:root{
  --bg:#070807;
  --board:#0b0d0b;
  --panel:#101210;
  --line:#242824;
  --volt:#E4F006;
  --volt-soft:#F0F77A;
  --volt-dim:#98A51F;
  --silk:#A2AB79;
  --silk-dim:#525A42;
  --text:#F4F5EF;
  --muted:#A4AA9E;
  --danger:#ff5d5d;
  --amber:#f2a623;
  --gold:#e8c547;
  --radius:18px;
  --mono:'JetBrains Mono',ui-monospace,monospace;
  --sans:'Inter',system-ui,sans-serif;
  --sp-1:6px; --sp-2:10px; --sp-3:14px; --sp-4:18px; --sp-5:28px; --sp-6:44px;
  --on-volt:#0a0c04;          /* text sitting on a volt fill */
  --placed:#f2f2f2;           /* the badge arc for prior expertise */
  --chip:#131512;             /* fast-track chip, resting */
  --chip-hover:#1A1D18;       /* and lifted — must differ, or hover reads as dead */
  --chip-line:#31362A;
  --chip-label:#D8E85C;
  --chip-muted:#909989;
  --line-lift:#30352f;        /* the lighter hairline, distinct from --line */
  --muted-2:#7E8579;          /* quieter caption than --muted */
  --label:#D5DF79;            /* palace and path-card titles */
  --field:#0d0f0d;            /* questions, cards, text inputs */
  --panel-2:#151714;          /* inset fields, a shade off --panel */
  --danger-soft:#ffd7d7;      /* wrong-answer text: pale reads, saturated does not */
  --danger-bg:#1a0d0d;
  --rail-line:#2b2f2b;
  --line-quiet:#202320;
  --on-volt-2:#0b0d07;
  --panel-lift:#171A16;       /* a soldered path card sits proud */
  --danger-line:#ff5c5c;
  --danger-text:#ffb4b4;
  --lesson-done:#98A51F;        /* an error box should look like one */
  --art-base-deep:#0d120e; --art-base-soft:#151b13; --art-base-surface:#1b2418; --art-base-board:#142218; --art-base-ink:#eef4e4; --art-base-line:#8a977d; --art-base-accent:#E4F006; --art-base-hot:#83c9ff; --art-base-glow:#E4F006;
  --art-elec-deep:#0d1117; --art-elec-soft:#111b20; --art-elec-surface:#13211d; --art-elec-board:#10271f; --art-elec-hot:#ff6c83;
  --art-mech-deep:#101111; --art-mech-soft:#171715; --art-mech-surface:#24251f; --art-mech-hot:#ffb44e;
  --art-mfg-deep:#101315; --art-mfg-soft:#151a1d; --art-mfg-surface:#20262a; --art-mfg-hot:#ff7a5c;
  --art-ai-deep:#101018; --art-ai-soft:#171624; --art-ai-surface:#211f32; --art-ai-hot:#bc87ff;
  --art-biz-deep:#101316; --art-biz-soft:#161c20; --art-biz-surface:#20272c; --art-biz-hot:#ff6d86;
  --art-ref-deep:#11120f; --art-ref-soft:#171a14; --art-ref-surface:#20251b; --art-ref-board:#171b15; --art-ref-hot:#ffb44e;
  --editorial-paper:#fbfbf6; --editorial-ink:#101214; --editorial-muted:#a7a7a1;
  --editorial-blue:#2f63d9; --editorial-red:#e9503e; --editorial-yellow:#e5ad25; --editorial-teal:#2a9d8f; --editorial-violet:#7961b2;
  --brand-editorial-ink:#f7f7f2; --brand-editorial-paper:#111214; --editorial-volt:#E4F006;
  --display:'Inter Tight','Inter',system-ui,sans-serif;
}

:root[data-theme="day"]{
  --bg:#ffffff;
  --board:#f4f6f9;
  --panel:#fafbfc;
  --line:#d9dfe9;
  --volt:#1341A0;
  --volt-soft:#0A3161;
  --volt-dim:#7a90c4;
  --silk:#B31942;
  --silk-dim:#d79aa7;
  --text:#101828;
  --muted:#5b6474;
  --danger:#B31942;
  --amber:#b05e00;
  --gold:#8a6d1a;
  --on-volt:#ffffff;
  --placed:#5b6474;
  --chip:#f4f6f9;
  --chip-hover:#e7ecf5;
  --chip-line:#c7d0e0;
  --chip-label:#1341A0;
  --chip-muted:#5b6474;
  --line-lift:#c7d0e0;
  --muted-2:#6b7385;
  --label:#1341A0;
  --field:#f7f9fc;
  --panel-2:#f4f6f9;
  --danger-soft:#8f1230;
  --danger-bg:#fdeff2;
  --rail-line:#d9dfe9;
  --line-quiet:#e4e9f1;
  --on-volt-2:#ffffff;
  --panel-lift:#eef2f8;
  --danger-line:#B31942;
  --danger-text:#8f1230;
  --day-blue:#1341A0; --day-navy:#0A3161; --day-red:#B31942; --day-pale:#f4f6f9; --level-ring-rest:#e1e7f0;
  --lesson-done:#8ea4ca;
  --art-base-deep:#eef3fb; --art-base-soft:#f7f9fc; --art-base-surface:#ffffff; --art-base-board:#e5edf8; --art-base-ink:#0A3161; --art-base-line:#8da1bf; --art-base-accent:#1341A0; --art-base-hot:#B31942; --art-base-glow:#8fa8d6;
  --art-elec-deep:#eef3fb; --art-elec-soft:#f7f9fc; --art-elec-surface:#ffffff; --art-elec-board:#e5edf8; --art-elec-hot:#B31942;
  --art-mech-deep:#eef3fb; --art-mech-soft:#f7f9fc; --art-mech-surface:#ffffff; --art-mech-hot:#B31942;
  --art-mfg-deep:#eef3fb; --art-mfg-soft:#f7f9fc; --art-mfg-surface:#ffffff; --art-mfg-hot:#B31942;
  --art-ai-deep:#eef3fb; --art-ai-soft:#f7f9fc; --art-ai-surface:#ffffff; --art-ai-hot:#B31942;
  --art-biz-deep:#eef3fb; --art-biz-soft:#f7f9fc; --art-biz-surface:#ffffff; --art-biz-hot:#B31942;
  --art-ref-deep:#eef3fb; --art-ref-soft:#f7f9fc; --art-ref-surface:#ffffff; --art-ref-board:#e5edf8; --art-ref-hot:#B31942;  --editorial-paper:#fbfbf6; --editorial-ink:#101214; --editorial-muted:#a7a7a1;
  --editorial-blue:#2f63d9; --editorial-red:#e9503e; --editorial-yellow:#e5ad25; --editorial-teal:#2a9d8f; --editorial-violet:#7961b2;
  --brand-editorial-ink:#0A3161; --brand-editorial-paper:#fbfbf6; --editorial-volt:#E4F006;
}
:root[data-theme="day"] .anim svg{background:#0b0b0a}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);font-size:16px;line-height:1.65}
a{color:var(--volt);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:980px;margin:0 auto;padding:20px 16px 80px}
header.learn{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:14px 0;border-bottom:1px solid var(--line);margin-bottom:20px}
header.learn .mark{font-family:var(--display);font-weight:600;letter-spacing:.02em}
header.learn .mark a{color:var(--text)}
header.learn nav{display:flex;gap:14px;font-family:var(--mono);font-size:13px}
h1{font-family:var(--display);font-weight:600;font-size:26px;line-height:1.2;letter-spacing:-.015em;margin:0 0 var(--sp-1)}
h2{font-family:var(--display);font-weight:600;font-size:19px;line-height:1.3;letter-spacing:-.01em;margin:var(--sp-5) 0 var(--sp-2)}
.silk{font-family:var(--mono);font-size:12px;color:var(--silk);letter-spacing:.04em}
.mono{font-family:var(--mono)}
.muted{color:var(--muted)}
.panel{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:16px}
.grid{display:grid;gap:16px}
@media(min-width:820px){.grid.dash{grid-template-columns:1fr 260px}}
button,.btn{appearance:none;border:1px solid var(--volt-dim);background:transparent;color:var(--volt);font-family:var(--mono);font-size:14px;padding:10px 16px;border-radius:8px;cursor:pointer;min-height:44px}
button:hover,.btn:hover{border-color:var(--volt);text-decoration:none}
button.primary,.btn.primary{background:var(--volt);color:var(--on-volt);border-color:var(--volt);font-weight:600}
button.quiet{border-color:var(--line);color:var(--muted)}
button:disabled{opacity:.35;cursor:default}
input[type=text],input[type=number],textarea,select{width:100%;background:var(--field);border:1px solid var(--line);border-radius:8px;color:var(--text);font-family:var(--mono);font-size:15px;padding:10px 12px}
textarea{min-height:140px;line-height:1.6;resize:vertical}
input:focus,textarea:focus,button:focus-visible,select:focus,a:focus-visible{outline:2px solid var(--volt);outline-offset:2px}
input[type=range]{width:100%;accent-color:var(--volt)}

/* readout */
.readout{display:flex;flex-direction:column;gap:14px}
.readout .big{font-family:var(--mono);font-size:40px;color:var(--volt);line-height:1}
.readout .label{font-family:var(--mono);font-size:12px;color:var(--silk);letter-spacing:.06em}
.readout .row{display:flex;justify-content:space-between;align-items:baseline;border-bottom:1px dashed var(--line);padding-bottom:8px}
.readout .val{font-family:var(--mono);color:var(--volt-soft)}
.readout .gloss{display:block;font-family:var(--mono);font-size:10.5px;color:var(--muted);letter-spacing:0;margin-top:2px;max-width:190px;line-height:1.45}

/* stage rail */
.rail{display:flex;gap:6px;flex-wrap:wrap;margin:14px 0 22px}
.rail .st{font-family:var(--mono);font-size:12px;color:var(--silk);border:1px solid var(--line);border-radius:999px;padding:6px 12px}
.rail .st.on{color:var(--on-volt);background:var(--volt);border-color:var(--volt)}
.rail .st.done{color:var(--volt-dim);border-color:var(--volt-dim)}

/* lesson content */
.lesson p{margin:0 0 var(--sp-3);max-width:66ch}
.lesson h2{margin:var(--sp-6) 0 var(--sp-2)}
.lesson h2:first-of-type{margin-top:var(--sp-4)}
.lesson h2::before{content:'';display:block;width:34px;height:4px;border-radius:2px;background:var(--volt);opacity:.9;margin-bottom:10px}
.lesson code{font-family:var(--mono);color:var(--volt-soft);font-size:.92em}
.bookref{font-family:var(--mono);font-size:12px;color:var(--silk);border-left:2px solid var(--silk-dim);padding:2px 0 2px 10px;margin:var(--sp-2) 0 var(--sp-4)}
.anim{background:var(--board);border:1px solid var(--line);border-radius:var(--radius);padding:var(--sp-3);margin:var(--sp-4) 0}
.anim .controls{display:flex;gap:10px;align-items:center;flex-wrap:wrap;margin-top:10px}
.anim svg{display:block;border-radius:10px;box-shadow:inset 0 0 0 1px var(--line)}
.anim .controls button{transition:border-color .15s ease,color .15s ease,transform .08s ease}
.anim .controls button:hover{border-color:var(--volt-dim)}
.anim .controls button:active{transform:translateY(1px)}
@media (prefers-reduced-motion: reduce){.anim .controls button{transition:none}}
.anim .cap{font-family:var(--mono);font-size:12px;color:var(--muted);margin-top:var(--sp-2);max-width:66ch}
.anim svg{display:block;width:100%;height:auto}
.sandbox{display:inline-block;margin:4px 0 16px}

/* quiz */
.q{border:1px solid var(--line);border-radius:var(--radius);padding:16px;margin:16px 0;background:var(--field)}
.q .prompt{font-weight:600;margin:0 0 12px}
.q .conf{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-bottom:12px}
.q .conf .label{font-family:var(--mono);font-size:12px;color:var(--silk)}
.q .conf button.sel{background:var(--volt);color:var(--on-volt);border-color:var(--volt)}
.q .opts{display:flex;flex-direction:column;gap:8px}
.q .opts button{text-align:left;font-family:var(--sans);color:var(--text);border-color:var(--line)}
.q .opts button.sel{border-color:var(--volt);color:var(--volt)}
.q .numrow{display:flex;gap:8px;align-items:center}
.q .numrow input{max-width:180px}
.q .unit{font-family:var(--mono);color:var(--muted)}
.q .fb{margin-top:12px;padding:12px;border-radius:8px;font-size:15px}
.q .fb.ok{border:1px solid var(--volt-dim);color:var(--volt-soft)}
.q .fb.no{border:1px solid var(--danger);color:var(--danger-soft)}
.q .fb .why{color:var(--muted);display:block;margin-top:6px}
.q .orderlist{display:flex;flex-direction:column;gap:8px}
.q .orderlist button{text-align:left;color:var(--text);border-color:var(--line)}
.q .picked{font-family:var(--mono);font-size:13px;color:var(--volt-soft);margin-top:8px;min-height:20px}
.q .matchrow{display:grid;grid-template-columns:1fr 1fr;gap:8px;align-items:center;margin-bottom:8px}

/* dump + summary */
.keypoints{list-style:none;padding:0;margin:12px 0}
.keypoints li{display:flex;gap:10px;align-items:flex-start;padding:8px 0;border-bottom:1px dashed var(--line)}
.keypoints input{width:auto;min-width:20px;accent-color:var(--volt)}

/* toast */
.toast-zone{position:fixed;left:0;right:0;bottom:18px;display:flex;flex-direction:column;align-items:center;gap:8px;pointer-events:none;z-index:50}
.toast{background:var(--volt);color:var(--on-volt);font-family:var(--mono);font-size:14px;font-weight:600;border-radius:8px;padding:10px 16px;opacity:0;transform:translateY(8px);transition:opacity .25s,transform .25s}
.toast.show{opacity:1;transform:none}

/* board */
.boardwrap{background:var(--board);border:1px solid var(--line);border-radius:14px;padding:10px}
.board-chip{cursor:default}
.board-chip.link{cursor:pointer}
.board-chip text{font-family:var(--mono)}

/* review */
.card{border:1px solid var(--line);border-radius:var(--radius);background:var(--field);padding:26px 20px;min-height:170px;display:flex;align-items:center;justify-content:center;text-align:center;font-size:19px;line-height:1.5}
.card .back{color:var(--volt-soft)}
.rate{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:14px}
.rate button.again{border-color:var(--danger);color:var(--danger)}
.rate button.hard{border-color:var(--amber);color:var(--amber)}
.progressbar{height:6px;background:var(--line);border-radius:3px;overflow:hidden;margin:12px 0}
.progressbar i{display:block;height:100%;background:var(--volt)}

.footer-silk{margin-top:40px;padding-top:14px;border-top:1px solid var(--line);font-family:var(--mono);font-size:12px;color:var(--silk-dim);display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap}

@media(prefers-reduced-motion:reduce){
  *{animation:none !important;transition:none !important}
}

/* drop 43: touch ergonomics — thumbs you can hit, sliders that use the phone's width */
input[type=range]{height:38px;margin:0}
@media (max-width:560px){
  .controls{gap:10px}
  .controls>div{width:100%;flex-wrap:wrap;row-gap:4px}
  .controls input[type=range]{max-width:none !important;width:100%;flex:1 1 100%}
  .controls .silk{min-width:0 !important}
  .controls input[type=number]{max-width:none !important;width:100%}
}

.theme-btn{min-height:32px;padding:4px 10px;font-size:12px;border-color:var(--line);color:var(--muted)}
.theme-btn:hover{border-color:var(--volt);color:var(--volt)}
.hook{font-family:var(--sans);font-size:13.5px;color:var(--muted);margin:2px 0 0;font-style:italic}

.sandbox-shell{margin:4px 0 18px}
.sandbox-frame{width:100%;height:min(62vh,520px);border:1px solid var(--line);border-radius:var(--radius);background:#0b0b0a;display:block}
.sandbox-note{display:flex;flex-wrap:wrap;gap:10px;align-items:baseline;margin:8px 0 0;font-size:12.5px;color:var(--muted);font-family:var(--mono)}
.sandbox-away{color:var(--volt-soft)}
@media(max-width:560px){.sandbox-frame{height:56vh}}

/* ---- the proving ground (gallery.html, unlisted) ---- */
.gal-bar{position:sticky;top:0;z-index:5;display:flex;flex-wrap:wrap;gap:8px;align-items:center;
  padding:10px 0;background:linear-gradient(var(--bg) 82%,transparent);}
.gal-filter{flex:1 1 220px;min-width:180px;background:var(--panel);border:1px solid var(--line);
  color:var(--text);border-radius:8px;padding:8px 12px;font:500 13px/1.2 'JetBrains Mono',monospace;}
.gal-filter:focus{outline:2px solid var(--volt-dim);outline-offset:1px;}
.gal-chip{background:var(--panel);border:1px solid var(--line);color:var(--muted);border-radius:999px;
  padding:5px 12px;font:600 12px/1 'JetBrains Mono',monospace;cursor:pointer;}
.gal-chip:hover{color:var(--volt);border-color:var(--volt-dim);}
.gal-h{margin:30px 0 12px;font-family:'Inter Tight',sans-serif;letter-spacing:.01em;}
.gal-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:14px;}
.gal-grid-sm{grid-template-columns:repeat(auto-fill,minmax(240px,1fr));}
.gal-card{transition:border-color .18s ease,transform .18s ease;}
.gal-card:hover{border-color:var(--volt-dim);transform:translateY(-1px);}
.gal-ph{min-height:120px;display:flex;align-items:center;justify-content:center;
  border:1px dashed var(--line);border-radius:8px;}
.beacon{position:fixed;top:0;bottom:0;left:-2px;width:2px;pointer-events:none;z-index:1;
  background:linear-gradient(180deg,transparent,var(--volt) 45%,var(--volt) 55%,transparent);
  opacity:.10;animation:beacon-sweep 16s linear infinite;}
@keyframes beacon-sweep{from{transform:translateX(-4px)}to{transform:translateX(100vw)}}
@media (prefers-reduced-motion: reduce){.beacon{display:none}.gal-card{transition:none}}
@media (max-width:520px){.gal-grid{grid-template-columns:1fr}}

/* ---- the bench (bench.html) ---- */
.bench-chassis{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:var(--sp-2)}
.bench-chassis input[type=range]{flex:1 1 84px;min-width:64px;height:26px}
.bench-chassis .cap{margin:0}
.bench-jog{accent-color:var(--silk-dim)}

/* ---- app shell (mobile) · d169 ---- */
.bottombar { display: none; }
@media (max-width: 720px) {
  body { padding-bottom: calc(66px + env(safe-area-inset-bottom, 0px)); }
  header.learn { padding: 10px 14px 6px; }
  header.learn .mark { font-size: 15px; }
  header.learn nav a { display: none; }
  .bottombar {
    position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
    display: grid; grid-template-columns: repeat(5, 1fr);
    background: var(--bg);
    border-top: 1px solid var(--silk-dim);
    padding: 6px 4px calc(6px + env(safe-area-inset-bottom, 0px));
  }
  .bb-item { display: flex; flex-direction: column; align-items: center; gap: 2px;
    text-decoration: none; color: var(--chip-muted); font-size: 10.5px; padding: 4px 0; min-height: 44px; }
  .bb-glyph { font-size: 17px; line-height: 1; }
  .bb-item.on { color: var(--volt); }
  .pathlist { display: flex; flex-direction: column; margin: 8px 0 12px; }
  .path-card { position: relative; display: flex; gap: 10px; padding: 11px 12px 11px 4px;
    border: 1px solid var(--silk-dim); border-radius: 14px; margin: 0 0 8px; background: var(--chip); cursor: pointer; }
  .pc-rail { width: 22px; display: flex; align-items: flex-start; justify-content: center; position: relative; flex: none; }
  .pc-rail::before { content: ''; position: absolute; top: -26px; bottom: -26px; width: 2px; background: var(--rail-line); }
  .path-card:first-child .pc-rail::before { top: 12px; }
  .path-card:last-child .pc-rail::before { bottom: auto; height: 12px; }
  .pc-dot { width: 12px; height: 12px; border-radius: 50%; background: var(--silk-dim); margin-top: 4px; z-index: 1; }
  .pc-body { display: flex; flex-direction: column; gap: 3px; min-width: 0; flex: 1; }
  .pc-top { display: flex; align-items: center; gap: 8px; justify-content: space-between; }
  .pc-title { font-family: var(--mono); font-size: 14.5px; color: var(--label); }
  .pc-state { font-size: 11px; color: var(--silk); font-family: var(--mono); }
  .pc-hook { font-size: 12.5px; color: var(--muted-2); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
  .pc-new { font-family: var(--mono); font-size: 10px; color: var(--on-volt-2); background: var(--volt); border-radius: 999px; padding: 2px 8px; }
  .pc-assume { font-size: 11px; margin-top: 2px; }
  .path-card.st-available { border-color: var(--volt-dim); }
  .path-card.st-available .pc-dot { background: var(--volt-dim); }
  .path-card.st-progress, .path-card.st-passed { border-color: var(--volt, #D6FF3F); box-shadow: 0 0 14px rgba(214, 255, 63, .08); }
  .path-card.st-progress .pc-dot, .path-card.st-passed .pc-dot { background: var(--volt, #D6FF3F); }
  .path-card.st-progress .pc-title, .path-card.st-passed .pc-title { color: var(--volt, #D6FF3F); }
  .path-card.st-soldered, .path-card.st-gold { border-color: var(--volt-dim); background: var(--panel-lift); }
  .path-card.st-soldered .pc-dot, .path-card.st-gold .pc-dot { background: var(--volt, #D6FF3F); }
  .path-card.st-locked { opacity: .62; }
  .grid.dash { grid-template-columns: 1fr; }
}

/* ---- the shelf: highlights, notes, bookmarks, tts · d170 ---- */
mark.hl { color: inherit; background: transparent; border-bottom: 2px solid; border-radius: 2px; padding: 0 1px; cursor: pointer; }
mark.hl-0 { border-color: var(--hl0, #f3e14c); background: color-mix(in srgb, var(--hl0, #f3e14c) 20%, transparent); }
mark.hl-1 { border-color: var(--hl1, #ff9d5c); background: color-mix(in srgb, var(--hl1, #ff9d5c) 20%, transparent); }
mark.hl-2 { border-color: var(--hl2, #6ecbff); background: color-mix(in srgb, var(--hl2, #6ecbff) 20%, transparent); }
mark.hl-3 { border-color: var(--hl3, #ff7fa8); background: color-mix(in srgb, var(--hl3, #ff7fa8) 20%, transparent); }
mark.hl-4 { border-color: var(--hl4, #8affc1); background: color-mix(in srgb, var(--hl4, #8affc1) 20%, transparent); }
.hl-palette { position: absolute; z-index: 70; display: none; gap: 7px; align-items: center;
  background: var(--chip); border: 1px solid var(--silk-dim); border-radius: 999px; padding: 7px 10px;
  box-shadow: 0 6px 22px rgba(0, 0, 0, .5); }
.hl-palette.show { display: flex; }
.hl-dot { width: 20px; height: 20px; border-radius: 50%; border: 1px solid rgba(0, 0, 0, .55); cursor: pointer; padding: 0; }
.hl-x { background: none; border: none; color: var(--muted-2); font-family: var(--mono); font-size: 13px; padding: 0 3px; cursor: pointer; }
.lsec { position: relative; }
.sec-head { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.sec-head h2 { margin-right: auto; }
.sec-tools { display: flex; gap: 5px; }
.sec-tools button { background: none; border: 1px solid var(--line-lift); color: var(--muted-2); border-radius: 8px;
  font-size: 12px; line-height: 1; padding: 4px 9px; cursor: pointer; font-family: var(--mono); }
.sec-tools button.on { color: var(--volt, #D6FF3F); border-color: var(--volt-dim); }
.note-box { width: 100%; min-height: 74px; background: var(--panel-2); color: inherit; border: 1px solid var(--line-lift);
  border-radius: 10px; padding: 8px 10px; font: inherit; font-size: 14px; margin: 4px 0 10px; }
.listen-bar { margin: 4px 0 14px; }
.shelf-item { border: 1px solid var(--line-lift); border-radius: 12px; padding: 10px 12px; margin: 0 0 10px; }
.shelf-item .hlchip { display: inline-block; width: 11px; height: 11px; border-radius: 50%; margin-right: 7px; vertical-align: baseline; }
.color-row { display: flex; gap: 12px; align-items: center; margin: 8px 0 4px; flex-wrap: wrap; }
.color-row input[type="color"] { width: 36px; height: 36px; border: 1px solid var(--line-lift); border-radius: 8px; background: none; padding: 2px; cursor: pointer; }
@media (max-width: 720px) { .bottombar { grid-template-columns: repeat(6, 1fr); } }

/* ---- error surface · d171 ---- */
.err-surface { position: fixed; top: 8px; left: 8px; right: 8px; z-index: 9999;
  background: var(--danger-bg); border: 1px solid var(--danger-line); color: var(--danger-text);
  font-family: var(--mono); font-size: 12px; line-height: 1.45;
  padding: 8px 11px; border-radius: 10px; white-space: pre-wrap; }

/* ---- fast-track rail + numbering note · d172 ---- */
.path-note { display: none; }
.paths-rail-wrap { margin: 14px 0 10px; }
.pr-head { display: block; text-decoration: none; margin: 0 0 4px; }
.pr-h1 { display: block; font-family: var(--display); font-weight: 600; font-size: 16px; color: var(--volt); }
.pr-h2 { display: block; font-size: 12.5px; color: var(--chip-muted); margin-top: 2px; }
.paths-rail { display: flex; gap: 12px; overflow-x: auto; padding: 8px 2px 6px;
  scrollbar-width: none; -webkit-overflow-scrolling: touch; }
.paths-rail::-webkit-scrollbar { display: none; }
.pr-chip { flex: none; width: 82px; display: flex; flex-direction: column; align-items: center;
  gap: 6px; text-decoration: none; }
.pr-chip svg { width: 56px; height: 56px; padding: 10px; box-sizing: border-box;
  border: 1.5px solid var(--chip-line); border-radius: 16px; background: var(--chip); display: block; }
.pr-chip:hover svg, .pr-chip:active svg { border-color: var(--volt); background: var(--chip-hover); }
.pr-label { font-family: var(--mono); font-size: 10.5px; color: var(--chip-label);
  text-align: center; white-space: nowrap; line-height: 1.35; }
@media (max-width: 720px) {
  .paths-rail-wrap { margin: 6px 0 12px; }
  .path-note { display: block; font-size: 11.5px; color: var(--silk); font-family: var(--mono);
    margin: 0 0 10px; }
  /* The rail was a sideways scroller on a phone, so most of the paths sat
     off-screen and undiscovered. Four to a row shows all of them at once. */
  .paths-rail { display: grid; grid-template-columns: repeat(4, 1fr);
    gap: 16px 8px; overflow-x: visible; padding: 10px 0 4px; }
  .pr-chip { width: auto; gap: 8px; }
  .pr-chip svg { width: 100%; max-width: 58px; height: auto; aspect-ratio: 1;
    margin: 0 auto; padding: 9px; }
  /* and a label has to wrap once it sits in a column rather than a strip */
  .pr-label { white-space: normal; font-size: 10px; line-height: 1.3;
    overflow-wrap: anywhere; hyphens: auto; }
}

/* ---- pegs · d174 ---- */
.peg-row { border-left: 2px solid var(--line-lift); padding: 6px 0 6px 12px; margin: 0 0 12px; }
.peg-mark { font-size: 13.5px; color: var(--label); line-height: 1.45; }
.peg-line { display: flex; gap: 8px; align-items: center; margin-top: 6px; }
.peg-input { flex: 1; min-width: 0; background: var(--panel-2); color: inherit; border: 1px solid var(--line-lift);
  border-radius: 9px; padding: 7px 10px; font: inherit; font-size: 14px; }
.peg-input:focus { border-color: var(--volt, #D6FF3F); outline: none; }
.peg-state { font-family: var(--mono); font-size: 11px; color: var(--volt, #D6FF3F); min-width: 62px; }
.card.peg-card { border-color: var(--volt-dim); }

/* ---- the memory palace · d175 ---- */
.room-card { border: 1px solid var(--silk-dim); border-radius: 14px; padding: 12px 14px; margin: 0 0 14px; background: var(--chip); }
.room-head { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; flex-wrap: wrap; }
.room-name { font-family: var(--display); font-weight: 600; font-size: 15.5px; color: var(--volt, #D6FF3F); margin-right: auto; }
.room-tools, .locus-tools { display: flex; gap: 5px; }
.room-tools button, .locus-tools button { background: none; border: 1px solid var(--line-lift); color: var(--muted-2);
  border-radius: 8px; font-size: 11.5px; line-height: 1; padding: 5px 8px; cursor: pointer; font-family: var(--mono); min-height: 30px; }
.room-tools button:hover, .locus-tools button:hover { border-color: var(--volt-dim); color: var(--chip-label); }
.locus-row { display: flex; gap: 10px; align-items: flex-start; padding: 8px 0; border-top: 1px solid var(--line-quiet); }
.locus-n { font-family: var(--mono); font-size: 11px; color: var(--silk); min-width: 16px; padding-top: 3px; }
.locus-mid { display: flex; flex-direction: column; gap: 3px; flex: 1; min-width: 0; }
.locus-name { font-size: 13.5px; color: var(--label); font-family: var(--mono); }
.locus-peg { font-size: 14px; color: var(--text, #e8ecdd); }
.locus-lm { font-size: 11.5px; color: var(--silk); }
.locus-sel { background: var(--panel-2); color: var(--muted-2); border: 1px solid var(--line-lift); border-radius: 8px;
  padding: 5px 8px; font: inherit; font-size: 12.5px; max-width: 100%; }
.locus-row.filled .locus-n { color: var(--volt, #D6FF3F); }
.walk-card { text-align: left; }
.walk-locus { font-family: var(--mono); font-size: 12px; color: var(--muted-2); margin-bottom: 8px; }
.walk-image { font-size: 19px; line-height: 1.4; color: var(--volt, #D6FF3F); }
.walk-back { font-size: 16px; margin-top: 10px; }
@media (max-width: 720px) { .bottombar { grid-template-columns: repeat(7, 1fr); } .bb-label { font-size: 9.5px; } }


/* ---- tighter rhythm · d180 ---- */
@media (max-width: 720px) {
  main { padding-top: 4px; }
  main > h1 { margin: 10px 0 4px; font-size: 26px; line-height: 1.15; }
  main > h2 { margin: 18px 0 6px; }
  main > p { margin: 6px 0; }
  main > p.silk, main > p.cap { margin: 3px 0 8px; }
  .pathlist { margin: 4px 0 10px; }
  .pc-rail::before { top: -18px; bottom: -18px; }
  .pc-body { gap: 2px; }
  .paths-rail-wrap { margin: 4px 0 10px; }
  .paths-rail { gap: 10px; padding: 6px 2px 4px; }
  .panel { padding: 11px 13px; margin: 8px 0; }
  .shelf-item { padding: 9px 11px; margin: 0 0 8px; }
  .room-card { padding: 10px 12px; margin: 0 0 10px; }
  .sim-controls { gap: 6px; margin: 6px 0; }
  .card { padding: 14px; }
}
/* track completion cards on the stats page */
.track-cards { display: grid; gap: .75rem; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.track-card { border: 1px solid var(--faint); border-left: 3px solid var(--volt); padding: .8rem .9rem; }
.track-card p { margin: .35rem 0 .6rem; }
.track-card button { margin-right: .4rem; }


/* --- mnemonics · shown after a recall attempt, never before one --- */
.mnemonic { margin: 18px 0 6px; padding: 14px 16px; border-left: 3px solid var(--volt);
  background: rgba(214,255,63,0.05); }
.mnem-of { margin: 0 0 6px; font-size: 12px; color: var(--muted); letter-spacing: .02em; }
.mnem-phrase { margin: 0 0 12px; font-family: var(--mono); font-size: 19px;
  color: var(--volt); letter-spacing: .01em; }
.mnem-steps { margin: 0; padding-left: 20px; }
.mnem-steps li { margin: 0 0 7px; font-size: 14px; line-height: 1.45; }
.mnem-steps li b { font-family: var(--mono); font-size: 13px; }
.mnem-why { margin: 12px 0 0; font-size: 13px; font-style: italic; }
@media (max-width: 640px) { .mnem-phrase { font-size: 16px; } }

.mnemcard { border-left: 3px solid var(--volt); }
.mnem-tag { margin: 0 0 10px; font-size: 11px; color: var(--volt);
  font-family: var(--mono); letter-spacing: .04em; }


/* ---- redesign first pass · mobile-first dashboard/course/lesson ---- */
body{font-size:16px;line-height:1.6;background:radial-gradient(circle at top, rgba(228,240,6,.06), transparent 28%), var(--bg)}
.wrap{max-width:1120px;padding:18px 16px 110px}
.panel{border-radius:20px;padding:18px;background:linear-gradient(180deg, rgba(255,255,255,.015), rgba(255,255,255,0)), var(--panel);box-shadow:0 18px 40px rgba(0,0,0,.22)}
button,.btn{border-radius:14px;border-color:var(--line-lift);font-family:var(--sans);font-weight:600;letter-spacing:-.01em}
button.primary,.btn.primary{box-shadow:0 8px 22px rgba(228,240,6,.16)}
header.learn{position:sticky;top:0;z-index:40;margin:0 0 20px;padding:14px 0 16px;background:linear-gradient(180deg,var(--bg) 78%,transparent);backdrop-filter:blur(14px);border-bottom:0}
header.learn .mark{display:flex;flex-direction:column;gap:2px}
header.learn .mark a{font-family:var(--display);font-size:17px;letter-spacing:-.02em}
.mark-sub{font-family:var(--sans);font-size:12px;color:var(--muted)}
header.learn nav{display:flex;align-items:center;gap:10px;font-family:var(--sans);font-size:14px}
header.learn nav a{color:var(--muted);padding:9px 12px;border-radius:999px}
header.learn nav a:hover,header.learn nav a.on{color:var(--text);background:rgba(255,255,255,.04);text-decoration:none}
.theme-btn{border-radius:999px;min-height:36px;padding:6px 12px}
.topnav{display:flex;align-items:center;gap:6px;flex-wrap:wrap}
h1{font-size:34px;letter-spacing:-.03em}
h2{font-size:24px;letter-spacing:-.025em}
.bookref{border-left:0;padding:0;color:var(--muted);font-family:var(--sans);font-size:15px;line-height:1.55}
.bookref--hero{max-width:60ch}
.hero-card,.action-card,.today-card,.course-hero,.lesson-pagehead{background:linear-gradient(180deg, rgba(255,255,255,.02), rgba(255,255,255,0)), var(--panel);border:1px solid var(--line);border-radius:24px;padding:22px;box-shadow:0 18px 44px rgba(0,0,0,.24)}
.hero-card--glow,.course-hero,.lesson-pagehead{position:relative;overflow:hidden}
.hero-card--glow::before,.course-hero::before,.lesson-pagehead::before{content:'';position:absolute;inset:auto -18% 78% -18%;height:120px;background:radial-gradient(circle, rgba(228,240,6,.18), rgba(228,240,6,0) 70%);pointer-events:none}
.hero-kicker,.section-kicker{font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--volt)}
.hero-title{margin:8px 0 8px;font-size:36px}
.hero-copy,.action-copy,.course-sub,.section-copy,.mini-course-card p,.library-card p,.tool-card p,.chapter-card p{color:var(--muted);max-width:70ch}
.home-layout,.course-layout{display:grid;gap:18px;align-items:start}
@media(min-width:930px){.home-layout,.course-layout{grid-template-columns:minmax(0,1fr) 320px}}
.home-shell{display:flex;flex-direction:column;gap:18px;min-width:0}
.action-head,.course-hero-head,.mini-course-top,.library-card-top,.chapter-top,.today-grid{display:flex;gap:14px;justify-content:space-between;align-items:flex-start}
.action-title{margin:4px 0 2px;font-size:28px}
.pct-badge{display:inline-flex;align-items:center;justify-content:center;min-width:68px;height:68px;padding:0 14px;border-radius:999px;background:rgba(228,240,6,.09);border:1px solid rgba(228,240,6,.22);font-family:var(--display);font-weight:700;font-size:22px;color:var(--volt)}
.pct-badge--lg{min-width:82px;height:82px;font-size:26px}
.progressbar{height:8px;background:rgba(255,255,255,.06);border-radius:999px}
.progressbar i{background:linear-gradient(90deg, var(--volt), var(--volt-soft))}
.progressbar--thick{height:10px}
.meta-row{display:flex;flex-wrap:wrap;gap:8px 16px;font-family:var(--mono);font-size:12px;color:var(--muted)}
.action-next,.mini-next,.library-note{margin:2px 0 0;color:var(--text)}
.cta-row,.chapter-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}
.section-head{display:flex;flex-direction:column;gap:4px;margin-top:2px}
.section-copy{margin:0}
.today-card{display:flex;flex-direction:column;gap:14px}
.today-grid{align-items:center}
.today-main{display:flex;gap:14px;align-items:center;flex:1;min-width:0}
.today-number{font-family:var(--display);font-size:46px;line-height:1;color:var(--volt);min-width:48px}
.today-copy{display:flex;flex-direction:column;gap:2px}
.today-copy strong{font-size:20px;letter-spacing:-.02em}
.today-copy span{color:var(--muted)}
.today-stats{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;width:100%}
.stat-pill{padding:14px 15px;border:1px solid var(--line);border-radius:18px;background:rgba(255,255,255,.02);display:flex;flex-direction:column;gap:4px}
.stat-pill strong{font-family:var(--display);font-size:18px;color:var(--text)}
.stat-pill span{font-size:12px;color:var(--muted);font-family:var(--mono)}
.mini-course-grid,.tool-grid,.library-stack{display:grid;gap:12px}
.mini-course-grid{grid-template-columns:repeat(auto-fit,minmax(240px,1fr))}
.tool-grid{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.mini-course-card,.tool-card,.library-card{position:relative;display:block;padding:18px;border:1px solid var(--line);border-radius:20px;background:var(--panel);text-decoration:none;transition:transform .14s ease,border-color .14s ease,background .14s ease}
.mini-course-card:hover,.tool-card:hover,.library-card:hover{transform:translateY(-1px);border-color:var(--volt-dim);text-decoration:none;background:var(--panel-lift)}
.mini-course-card h3,.tool-card h3,.library-card h3,.chapter-card h3{margin:0 0 3px;font-size:18px;font-family:var(--display);color:var(--text)}
.mini-course-card p,.tool-card p,.library-card p,.chapter-card p{margin:0;font-size:14px}
.mini-course-pct,.library-meta,.chapter-state{font-family:var(--mono);font-size:12px;color:var(--volt-soft)}
.mini-badge{position:absolute;right:14px;bottom:14px;opacity:.95}
.library-fold{padding:12px 14px}
.library-fold summary{cursor:pointer;list-style:none}
.library-fold summary::-webkit-details-marker{display:none}
.library-fold-summary{font-family:var(--display);font-size:18px;font-weight:600;color:var(--text)}
.library-stack{margin-top:12px}
.library-stage-head{margin:6px 0 2px}
.library-stage-name{font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--volt)}
.library-stage-copy{font-size:13px;color:var(--muted)}
.library-card--muted{opacity:.72}
.course-layout{margin-top:18px}
.chapter-list{display:flex;flex-direction:column;gap:12px}
.chapter-card{display:grid;grid-template-columns:56px minmax(0,1fr);gap:14px;padding:18px;border:1px solid var(--line);border-radius:22px;background:var(--panel)}
.chapter-index{display:flex;align-items:flex-start;justify-content:center;padding-top:2px;font-family:var(--display);font-size:28px;color:var(--volt)}
.chapter-body{min-width:0}
.chapter-card--progress,.chapter-card--next{border-color:rgba(228,240,6,.24);background:linear-gradient(180deg, rgba(228,240,6,.04), rgba(228,240,6,0)), var(--panel)}
.chapter-card--done{border-color:var(--line-lift)}
.course-map-fold{margin-top:16px}
.course-map-fold[open]{padding-bottom:16px}
.lesson-pagehead{margin-bottom:14px}
.crumb-back{display:inline-flex;align-items:center;gap:8px;margin-bottom:14px;color:var(--muted);font-family:var(--sans);font-weight:600}
.crumb-back:hover{color:var(--text);text-decoration:none}
.lesson-pill-row{display:flex;gap:8px;flex-wrap:wrap}
.lesson-pill{display:inline-flex;align-items:center;padding:7px 12px;border-radius:999px;background:rgba(255,255,255,.04);border:1px solid var(--line);font-family:var(--mono);font-size:11px;color:var(--muted)}
.lesson-stagebar{display:grid;grid-template-columns:repeat(5,1fr);gap:8px;margin:0 0 14px}
.lesson-stagebar .st{display:flex;align-items:center;justify-content:center;min-height:44px;padding:9px 10px;border-radius:14px;border:1px solid var(--line);background:rgba(255,255,255,.02);font-family:var(--sans);font-size:13px;color:var(--muted)}
.lesson-stagebar .st.on{background:var(--volt);color:var(--on-volt);border-color:var(--volt);font-weight:700}
.lesson-stagebar .st.done{border-color:rgba(228,240,6,.28);color:var(--volt-soft)}
.lesson-focus.panel{padding:22px}
.lesson-card .listen-bar{position:sticky;top:78px;z-index:5;padding:0 0 12px;background:linear-gradient(180deg, var(--panel) 72%, rgba(16,18,16,0))}
.lesson p{font-size:17px;line-height:1.72;max-width:68ch;color:var(--text)}
.lesson h2{font-size:26px;margin:30px 0 10px}
.lesson .anim,.q{border-radius:20px;border-color:var(--line-lift);background:linear-gradient(180deg, rgba(255,255,255,.02), rgba(255,255,255,0)), var(--field)}
.q .prompt{font-size:17px;line-height:1.5}
.sec-head{align-items:flex-start;gap:12px}
.sec-head h2{margin-right:auto}
.sec-tools{gap:8px}
.sec-tools button{min-height:36px;padding:7px 10px;border-radius:12px;background:rgba(255,255,255,.02)}
.note-box,.peg-input{border-radius:14px;background:var(--panel-2)}
.paths-rail-wrap{margin:0}
.pr-head{margin-bottom:10px}
.pr-h1{font-size:18px;color:var(--text)}
.pr-h2{font-size:14px}
.paths-rail{display:grid;grid-template-columns:repeat(auto-fit,minmax(90px,1fr));gap:12px;overflow:visible;padding:0}
.pr-chip{width:auto;border-radius:18px;padding:12px 10px 10px;border:1px solid var(--line);background:var(--panel);align-items:center;justify-content:flex-start}
.pr-chip svg{width:56px;height:56px;background:var(--chip);border-color:var(--line-lift)}
.pr-label{font-size:11px;color:var(--text)}
.readout{position:sticky;top:96px;border-radius:22px}
.readout .big{font-size:48px}
.readout .row{padding-bottom:10px}
.footer-silk{font-size:12px;gap:12px}
@media (max-width: 930px){
  .readout{position:static}
}
@media (max-width: 720px){
  body{padding-bottom:calc(78px + env(safe-area-inset-bottom, 0px))}
  .wrap{padding:12px 14px 98px}
  header.learn{padding:10px 0 12px}
  header.learn .mark a{font-size:16px}
  .mark-sub{display:none}
  header.learn nav a{display:none}
  .theme-btn{display:none}
  .bottombar{position:fixed;left:12px;right:12px;bottom:10px;z-index:70;display:grid;grid-template-columns:repeat(5,1fr);gap:4px;padding:7px 6px calc(7px + env(safe-area-inset-bottom, 0px));border:1px solid var(--line);border-radius:22px;background:color-mix(in srgb,var(--bg) 92%,transparent);backdrop-filter:blur(18px);box-shadow:0 16px 36px rgba(0,0,0,.36)}
  .bb-item{display:flex;flex-direction:column;align-items:center;gap:5px;padding:6px 0 4px;min-height:54px;color:var(--muted);text-decoration:none;border-radius:14px}
  .bb-item.on{color:var(--text);background:rgba(228,240,6,.08)}
  .bb-glyph{display:flex;align-items:center;justify-content:center;width:20px;height:20px}
  .bb-glyph svg{width:20px;height:20px;display:block}
  .bb-label{font-size:10.5px;font-family:var(--sans);font-weight:600}
  .hero-card,.action-card,.today-card,.course-hero,.lesson-pagehead,.panel{padding:18px;border-radius:22px}
  h1,.hero-title{font-size:30px}
  .action-title{font-size:24px}
  .today-grid,.action-head,.course-hero-head{flex-direction:column}
  .today-main{align-items:flex-start}
  .today-stats{grid-template-columns:1fr}
  .pct-badge,.pct-badge--lg{min-width:64px;height:64px;font-size:22px}
  .mini-course-grid,.tool-grid,.library-stack{grid-template-columns:1fr}
  .chapter-card{grid-template-columns:1fr}
  .chapter-index{justify-content:flex-start;font-size:22px;padding-top:0}
  .lesson-stagebar{grid-template-columns:1fr;gap:8px}
  .lesson-focus.panel{padding:18px}
  .lesson-card .listen-bar{top:68px}
  .lesson p{font-size:16.5px;line-height:1.68}
  .sec-head{flex-direction:column;align-items:flex-start}
  .sec-tools{width:100%;overflow:auto;padding-bottom:2px}
  .paths-rail{grid-template-columns:repeat(3,minmax(0,1fr))}
}


/* ---- pass 2 refinement: sessions, quizzes, stronger app feel ---- */
.session-shell{display:flex;flex-direction:column;gap:16px}
.session-hero,.session-meter-card,.session-stage-card{background:linear-gradient(180deg, rgba(255,255,255,.022), rgba(255,255,255,0)), var(--panel);border:1px solid var(--line);border-radius:24px;box-shadow:0 18px 44px rgba(0,0,0,.24)}
.session-hero{padding:22px;position:relative;overflow:hidden}
.session-hero::before{content:'';position:absolute;inset:auto -14% 76% -14%;height:120px;background:radial-gradient(circle, rgba(228,240,6,.16), rgba(228,240,6,0) 72%);pointer-events:none}
.session-meter-card,.session-stage-card{padding:18px 20px}
.session-meter-top{display:flex;justify-content:space-between;gap:12px;align-items:center;flex-wrap:wrap;font-family:var(--mono);font-size:12px;color:var(--muted)}
.session-meter-top strong{font-size:13px;color:var(--text)}
.session-pill-row{display:grid;grid-template-columns:repeat(auto-fit,minmax(120px,1fr));gap:10px;margin-top:16px}
.session-pill{padding:14px 15px;border-radius:18px;border:1px solid var(--line);background:rgba(255,255,255,.02);display:flex;flex-direction:column;gap:4px}
.session-pill strong{font-family:var(--display);font-size:20px;color:var(--text);letter-spacing:-.02em}
.session-pill span{font-family:var(--mono);font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.08em}
.session-stage-head{display:flex;flex-direction:column;gap:4px;margin-bottom:14px}
.session-stage-head h2{margin:0}
.session-flashcard{min-height:240px;border-radius:24px;background:linear-gradient(180deg, rgba(228,240,6,.035), rgba(255,255,255,0)), var(--field);box-shadow:inset 0 1px 0 rgba(255,255,255,.03)}
.session-primary-btn{min-width:180px}
.session-grade-row{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-top:16px}
.session-grade{min-height:54px;border-radius:16px;font-size:15px;font-weight:700;background:rgba(255,255,255,.02)}
.session-grade.again{border-color:rgba(238,87,99,.5);color:var(--danger-text)}
.session-grade.hard{border-color:rgba(255,177,74,.55);color:var(--amber)}
.session-grade.good{border-color:rgba(228,240,6,.28);color:var(--text);background:rgba(228,240,6,.06)}
.session-grade.easy{border-color:rgba(110,203,255,.34);color:var(--volt-soft)}
.session-input{height:52px;padding:0 14px;border-radius:16px;border:1px solid var(--line-lift);background:var(--panel-2);color:var(--text);font:600 17px/1 var(--sans)}
.session-input:focus{outline:none;border-color:var(--volt);box-shadow:0 0 0 3px rgba(228,240,6,.08)}
.session-input-row{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:6px}
.session-feedback{min-height:26px;margin:12px 0 0;color:var(--muted)}
.session-feedback.ok{color:var(--volt-soft)}
.session-feedback.warn{color:var(--amber)}
.q{padding:18px 18px 16px}
.q .prompt{font-size:18px;line-height:1.55;letter-spacing:-.01em}
.q .conf{gap:10px;margin-bottom:14px}
.q .conf .label{font-size:11px;letter-spacing:.08em;text-transform:uppercase}
.q .conf button{min-height:38px;padding:0 12px;border-radius:999px;background:rgba(255,255,255,.02)}
.q .opts button,.q .orderlist button,.q select,.q input[type='number']{min-height:48px;border-radius:14px;background:rgba(255,255,255,.02)}
.q .opts button,.q .orderlist button{padding:11px 14px;font-size:15px}
.q select,.q input[type='number']{padding:0 12px;color:var(--text);border:1px solid var(--line-lift)}
.q .numrow{align-items:center;flex-wrap:wrap}
.q .numrow input{height:48px;border-radius:14px;background:rgba(255,255,255,.02);color:var(--text);border:1px solid var(--line-lift)}
.q .fb{border-radius:14px;padding:14px 15px;font-size:15px;line-height:1.5}
.q .fb.ok{background:rgba(228,240,6,.05)}
.q .fb.no{background:rgba(238,87,99,.05)}
.note-box::placeholder,.peg-input::placeholder,.session-input::placeholder{color:var(--muted-2)}
@media (max-width:720px){
  .session-hero,.session-meter-card,.session-stage-card{padding:18px}
  .session-pill-row{grid-template-columns:repeat(2,minmax(0,1fr))}
  .session-flashcard{min-height:210px;font-size:18px}
  .session-grade-row{grid-template-columns:repeat(2,1fr)}
  .session-grade{min-height:50px}
  .q .prompt{font-size:17px}
}


/* ---- pass 3 brand polish: The Lighthouse ---- */
header.learn .mark a{font-size:18px;font-weight:700;letter-spacing:-.03em}
.mark-sub{letter-spacing:.01em}
header.learn nav a,.bb-label{font-weight:600}
@media (max-width:720px){
  .bb-label{font-size:10px}
}


/* ---- pass 4 identity polish: premium Lighthouse brand ---- */
header.learn{padding:12px 0 16px}
.brand-lockup{display:flex;align-items:center;gap:12px}
.brand-type{display:flex;flex-direction:column;gap:2px}
.brand-mark{display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;border-radius:14px;border:1px solid rgba(228,240,6,.2);background:linear-gradient(180deg, rgba(228,240,6,.09), rgba(228,240,6,.02));color:var(--volt);box-shadow:0 10px 24px rgba(0,0,0,.22), inset 0 1px 0 rgba(255,255,255,.05)}
.brand-mark svg{width:28px;height:28px;display:block}
header.learn .mark a{font-size:19px}
.mark-sub{font-size:11.5px;color:var(--silk);text-transform:uppercase;letter-spacing:.12em}
header.learn nav{gap:8px}
header.learn nav a{border:1px solid transparent;padding:9px 13px}
header.learn nav a:hover,header.learn nav a.on{border-color:rgba(228,240,6,.16);background:rgba(228,240,6,.06);color:var(--text);box-shadow:inset 0 1px 0 rgba(255,255,255,.03)}
.hero-card,.action-card,.today-card,.course-hero,.lesson-pagehead,.session-hero,.session-meter-card,.session-stage-card{box-shadow:0 20px 50px rgba(0,0,0,.28)}
.hero-kicker,.section-kicker{color:var(--volt-soft)}
.bb-item.on{box-shadow:inset 0 1px 0 rgba(255,255,255,.03)}
.footer-silk{border-top:1px solid rgba(255,255,255,.04);padding-top:18px;margin-top:18px}
@media (max-width:720px){
  .brand-lockup{gap:10px}
  .brand-mark{width:40px;height:40px;border-radius:12px}
  .brand-mark svg{width:24px;height:24px}
  header.learn .mark a{font-size:17px}
  .mark-sub{font-size:10px;letter-spacing:.11em}
}

/* ---- pass 5 final app polish: You, Shelf, Palace, Tools, empty states ---- */
.profile-hero,.personal-hero,.tools-hero,.about-hero{
  position:relative;overflow:hidden;
  background:linear-gradient(180deg,rgba(255,255,255,.025),rgba(255,255,255,0)),var(--panel);
  border:1px solid var(--line);border-radius:26px;padding:24px;
  box-shadow:0 22px 54px rgba(0,0,0,.3);margin-bottom:18px;
}
.profile-hero::before,.personal-hero::before,.tools-hero::before,.about-hero::before{
  content:'';position:absolute;left:-10%;right:-10%;top:-82px;height:170px;
  background:radial-gradient(circle at 28% 60%,rgba(228,240,6,.17),rgba(228,240,6,0) 58%);pointer-events:none;
}
.profile-hero-top{display:flex;justify-content:space-between;gap:18px;align-items:flex-start}
.rail-orb{width:92px;height:92px;flex:0 0 92px;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;
  border:1px solid rgba(228,240,6,.28);background:radial-gradient(circle at 50% 35%,rgba(228,240,6,.15),rgba(228,240,6,.035) 60%,transparent 61%);box-shadow:0 12px 30px rgba(0,0,0,.25)}
.rail-orb-label{font:500 10px/1 var(--mono);letter-spacing:.12em;text-transform:uppercase;color:var(--silk)}
.rail-orb strong{font:700 31px/1 var(--display);color:var(--volt);margin-top:6px}
.profile-metrics{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin-top:18px}
.profile-metric{padding:13px 14px;border:1px solid var(--line);border-radius:17px;background:rgba(255,255,255,.02);display:flex;flex-direction:column;gap:2px;min-width:0}
.profile-metric strong{font:700 20px/1.15 var(--display);color:var(--text);letter-spacing:-.02em}
.profile-metric span{font:500 10.5px/1.35 var(--mono);text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.profile-layout{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(300px,.9fr);gap:16px;align-items:start}
.profile-main{display:flex;flex-direction:column;gap:16px}
.profile-card,.personal-card{background:linear-gradient(180deg,rgba(255,255,255,.018),rgba(255,255,255,0)),var(--panel);border:1px solid var(--line);border-radius:22px;padding:19px;box-shadow:0 16px 36px rgba(0,0,0,.2)}
.profile-section-head{margin-bottom:15px}
.profile-section-head h2{margin:0 0 4px;font-size:21px}
.profile-section-head p{margin:0;color:var(--muted);font-size:14px}
.profile-stat-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.profile-stat-tile{border:1px solid var(--line);border-radius:16px;padding:14px;background:rgba(255,255,255,.018);display:flex;flex-direction:column;gap:4px}
.profile-stat-tile strong{font:700 23px/1 var(--display);color:var(--text)}
.profile-stat-tile span{font-size:12px;color:var(--muted)}
.cal-row{margin:0 0 14px}.cal-top{display:flex;justify-content:space-between;gap:10px;margin-bottom:7px;font-size:13px;color:var(--muted)}
.cal-top strong{font-family:var(--mono);font-size:12px;color:var(--text)}
.profile-note{margin:12px 0 0;padding:12px 13px;border-radius:14px;background:rgba(255,255,255,.025);color:var(--muted);font-size:13.5px}
.badge-grid{display:grid;grid-template-columns:1fr;gap:9px}
.badge-tile{display:grid;grid-template-columns:32px 1fr;gap:11px;padding:12px;border:1px solid var(--line);border-radius:16px;background:rgba(255,255,255,.015);opacity:.62}
.badge-tile.earned{opacity:1;border-color:rgba(228,240,6,.24);background:rgba(228,240,6,.035)}
.badge-icon{width:32px;height:32px;border-radius:10px;border:1px solid var(--line);display:flex;align-items:center;justify-content:center;font-family:var(--mono);color:var(--muted)}
.badge-tile.earned .badge-icon{color:var(--on-volt);background:var(--volt);border-color:var(--volt)}
.badge-tile strong{font-family:var(--display);font-size:14.5px;color:var(--text)}
.badge-tile p{margin:2px 0 4px;font-size:12.5px;color:var(--muted);line-height:1.45}
.badge-meta{font-family:var(--mono);font-size:10.5px;color:var(--silk)}
.settings-actions{display:flex;gap:9px;flex-wrap:wrap}.danger-action{border-color:rgba(255,93,93,.38)!important;color:var(--danger-text)!important}
.empty-state{padding:16px;border:1px dashed var(--line-lift);border-radius:17px;background:rgba(255,255,255,.012)}
.empty-state strong{display:block;font-family:var(--display);font-size:15px;color:var(--text)}
.empty-state p{margin:4px 0 0;color:var(--muted);font-size:13.5px;line-height:1.5}
.empty-state--large{padding:24px;text-align:center;margin-top:14px}
.personal-shell{display:flex;flex-direction:column;gap:16px}.personal-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.personal-card--collection{min-width:0}.collection-list{display:flex;flex-direction:column;gap:9px}
.collection-item{display:flex;gap:11px;align-items:flex-start;padding:12px 13px;border:1px solid var(--line);border-radius:16px;background:rgba(255,255,255,.015);min-width:0}
.collection-item--stacked{flex-direction:column}.collection-main{display:flex;flex-direction:column;gap:3px;min-width:0;flex:1}
.collection-main strong{font-size:14px;color:var(--text);line-height:1.45;overflow-wrap:anywhere}.collection-main span,.collection-main a{font-size:12px;color:var(--muted);line-height:1.4}
.collection-note{margin:7px 0 0}.icon-btn{min-width:34px;width:34px;height:34px;min-height:34px;padding:0;border-radius:11px;border:1px solid var(--line);background:rgba(255,255,255,.018);color:var(--muted);font-family:var(--sans);font-size:16px;flex:0 0 34px}
.icon-btn:hover{border-color:var(--volt-dim);color:var(--text)}
.color-row--polished{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:9px;margin-bottom:15px}.pen-chip{display:flex;flex-direction:column;gap:6px;align-items:center;padding:10px 6px;border:1px solid var(--line);border-radius:15px;background:rgba(255,255,255,.015);font-size:10px;color:var(--muted)}
.pen-chip input[type=color]{width:34px;height:34px;border-radius:50%;border:0;padding:0;overflow:hidden}.reading-settings{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(0,1fr) auto;gap:12px;align-items:end}
.reading-settings label{display:flex;flex-direction:column;gap:6px;color:var(--muted);font-size:12px}.shelf-select{min-height:44px;border-radius:13px;background:var(--field);color:var(--text);border:1px solid var(--line)}
.range-with-value{display:flex;gap:9px;align-items:center}.range-with-value input{flex:1}
.palace-body{display:flex;flex-direction:column;gap:16px}.palace-room-list{display:flex;flex-direction:column;gap:12px}.room-card--polished{padding:16px;border-color:var(--line);background:linear-gradient(180deg,rgba(255,255,255,.018),rgba(255,255,255,0)),var(--panel)}
.room-index{display:block;font:500 10px/1.2 var(--mono);letter-spacing:.1em;text-transform:uppercase;color:var(--silk);margin-bottom:4px}.room-card--polished .room-name{font-size:18px;color:var(--text)}
.room-card--polished .room-tools,.room-card--polished .locus-tools{gap:6px}.room-card--polished .locus-row{border-top:1px solid var(--line);padding:12px 0}.room-card--polished .locus-name{color:var(--text);font-family:var(--sans);font-weight:600}
.room-card--polished .locus-lm{color:var(--muted)}.room-card--polished .locus-sel{min-height:42px;border-radius:12px;background:var(--field);border-color:var(--line)}
.reveal-panel{margin-top:12px;padding:16px;border-radius:16px;border:1px solid rgba(228,240,6,.2);background:rgba(228,240,6,.045);color:var(--volt-soft)}
.tools-hero{margin-bottom:14px}.tool-machine-fold{margin:0 0 16px!important;border-color:var(--line)!important}.tool-machine-fold>summary{font-size:17px;color:var(--text)}
.tool-group-nav{display:flex;gap:8px;overflow-x:auto;scrollbar-width:none;padding:2px 0 14px;margin-bottom:4px;position:sticky;top:82px;z-index:20;background:linear-gradient(var(--bg) 72%,transparent)}.tool-group-nav::-webkit-scrollbar{display:none}
.tool-group-nav a{flex:none;padding:8px 12px;border:1px solid var(--line);border-radius:999px;background:color-mix(in srgb,var(--bg) 90%,transparent);backdrop-filter:blur(10px);font:500 11px/1 var(--mono);color:var(--muted);text-decoration:none}.tool-group-nav a:hover{color:var(--text);border-color:var(--volt-dim)}
.tool-group{scroll-margin-top:140px;margin:0 0 24px}.toolbench-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:13px}.toolbench-card{min-width:0;padding:17px;border:1px solid var(--line);border-radius:21px;background:linear-gradient(180deg,rgba(255,255,255,.02),rgba(255,255,255,0)),var(--panel);box-shadow:0 14px 34px rgba(0,0,0,.19)}
.toolbench-card-head h3{margin:5px 0 4px;font:600 18px/1.3 var(--display);color:var(--text)}.toolbench-card-head p{margin:0;color:var(--muted);font-size:13.5px;line-height:1.5}.toolbench-stage{margin-top:13px}.tool-learn-link{display:block;margin-top:13px;padding-top:11px;border-top:1px solid var(--line);font-size:12px;color:var(--volt-soft)}
.about-hero{margin-top:0}.about-hero h1{max-width:720px}.about-hero+.panel{margin-top:0}.about-hero~.panel{margin-bottom:14px}.about-hero~.panel h2{font-size:20px}.about-hero~.panel p{color:var(--muted);max-width:76ch}.about-hero~.panel p .mono{color:var(--text)!important}

/* motion stays subtle and functional */
@media (prefers-reduced-motion:no-preference){
  .mini-course-card,.tool-card,.library-card,.chapter-card,.profile-card,.personal-card,.toolbench-card,.collection-item,.room-card--polished{transition:transform .14s ease,border-color .14s ease,background .14s ease,box-shadow .14s ease}
  .profile-card:hover,.personal-card:hover,.toolbench-card:hover{border-color:var(--line-lift)}
  .toolbench-card:hover{transform:translateY(-1px);box-shadow:0 18px 40px rgba(0,0,0,.24)}
  button,.btn,.bb-item,.icon-btn{transition:transform .08s ease,border-color .14s ease,background .14s ease,color .14s ease}
  button:active,.btn:active,.bb-item:active,.icon-btn:active{transform:scale(.985)}
}

@media(max-width:930px){.profile-layout{grid-template-columns:1fr}.badge-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.toolbench-grid{grid-template-columns:1fr}.tool-group-nav{top:72px}}
@media(max-width:720px){
  .profile-hero,.personal-hero,.tools-hero,.about-hero{padding:19px;border-radius:22px}.profile-hero-top{flex-direction:column}.rail-orb{width:76px;height:76px;flex-basis:76px}.rail-orb strong{font-size:26px}
  .profile-metrics{grid-template-columns:repeat(2,minmax(0,1fr))}.profile-stat-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.personal-grid{grid-template-columns:1fr}.badge-grid{grid-template-columns:1fr}.color-row--polished{grid-template-columns:repeat(5,minmax(0,1fr));gap:5px}.pen-chip{padding:8px 2px}.pen-chip span{font-size:9px}.reading-settings{grid-template-columns:1fr}.reading-settings button{width:100%}
  .room-head{align-items:flex-start}.room-card--polished .room-tools{width:auto;flex-wrap:wrap;justify-content:flex-end}.locus-row{flex-wrap:wrap}.locus-tools{margin-left:26px}.tool-group-nav{top:64px;margin-left:-14px;margin-right:-14px;padding-left:14px;padding-right:14px}.toolbench-card{padding:15px}
}

/* ---- pass 6 product behavior: onboarding, discovery, resume, chapter spine ---- */
.onboarding-card{
  position:relative;overflow:hidden;padding:22px;border:1px solid rgba(228,240,6,.2);border-radius:24px;
  background:linear-gradient(145deg,rgba(228,240,6,.07),rgba(255,255,255,.018) 40%,rgba(255,255,255,0)),var(--panel);
  box-shadow:0 20px 46px rgba(0,0,0,.26)
}
.onboarding-card h2{margin:5px 0 5px;font-size:25px}
.onboarding-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-top:16px}
.onboarding-choice{display:flex;flex-direction:column;gap:6px;min-height:138px;padding:16px;border:1px solid var(--line);border-radius:18px;background:rgba(255,255,255,.018);text-decoration:none;color:var(--text);transition:transform .14s ease,border-color .14s ease,background .14s ease}
.onboarding-choice:hover{transform:translateY(-1px);border-color:rgba(228,240,6,.3);background:rgba(228,240,6,.035);text-decoration:none}
.onboarding-choice strong{font:700 17px/1.25 var(--display);color:var(--text)}
.onboarding-choice span{font-size:13.5px;line-height:1.5;color:var(--muted);flex:1}
.onboarding-choice b{font:600 12px/1.2 var(--mono);color:var(--volt);letter-spacing:.02em}
.onboarding-skip{margin-top:12px}
.library-browser{scroll-margin-top:92px;border:1px solid var(--line);border-radius:22px;padding:16px;background:linear-gradient(180deg,rgba(255,255,255,.018),transparent),var(--panel)}
.library-search-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:10px;align-items:center}
.library-search-input,.global-search-input{width:100%;height:50px;padding:0 15px;border:1px solid var(--line-lift);border-radius:15px;background:var(--field);color:var(--text);font:500 15px/1 var(--sans)}
.library-search-input:focus,.global-search-input:focus{outline:none;border-color:var(--volt);box-shadow:0 0 0 3px rgba(228,240,6,.08)}
.library-deep-search{white-space:nowrap}
.library-filter-row{display:flex;gap:8px;overflow-x:auto;padding:12px 0 8px;scrollbar-width:none}
.library-filter-row::-webkit-scrollbar{display:none}
.library-filter-chip{flex:none;min-height:38px;padding:7px 12px;border-radius:999px;border:1px solid var(--line);background:rgba(255,255,255,.015);color:var(--muted);font:600 12px/1 var(--sans)}
.library-filter-chip.on{border-color:rgba(228,240,6,.3);background:rgba(228,240,6,.09);color:var(--text)}
.library-browser-status{min-height:20px;margin:3px 2px 8px;font:500 11px/1.4 var(--mono);color:var(--muted)}
.library-browser-results .library-stack{gap:10px}
.search-hero{position:relative;overflow:hidden;margin-bottom:14px;padding:22px;border:1px solid var(--line);border-radius:24px;background:linear-gradient(180deg,rgba(255,255,255,.022),transparent),var(--panel);box-shadow:0 20px 46px rgba(0,0,0,.26)}
.search-hero::before{content:'';position:absolute;left:-8%;right:-8%;top:-92px;height:170px;background:radial-gradient(circle at 25% 70%,rgba(228,240,6,.16),transparent 58%);pointer-events:none}
.global-search-input{margin:0 0 4px}
.search-status{min-height:20px;margin:10px 2px 4px;font:500 11px/1.45 var(--mono);color:var(--muted)}
.search-results{display:flex;flex-direction:column;gap:9px;margin-top:6px}
.search-result-card{display:flex;flex-direction:column;gap:4px;padding:14px 16px;border:1px solid var(--line);border-radius:17px;background:var(--panel);text-decoration:none;transition:border-color .14s ease,transform .14s ease,background .14s ease}
.search-result-card:hover{border-color:rgba(228,240,6,.28);background:var(--panel-lift);transform:translateY(-1px);text-decoration:none}
.search-result-card strong{font:650 16px/1.35 var(--display);color:var(--text)}
.search-result-card span{font:500 11.5px/1.4 var(--mono);color:var(--muted)}
.chapter-spine{position:relative;padding-left:20px}
.chapter-spine::before{content:'';position:absolute;left:42px;top:25px;bottom:25px;width:2px;background:linear-gradient(180deg,rgba(228,240,6,.25),var(--line) 36%,var(--line));border-radius:999px}
.chapter-spine .chapter-card{position:relative;grid-template-columns:62px minmax(0,1fr);padding:18px 18px 18px 8px;background:linear-gradient(180deg,rgba(255,255,255,.018),transparent),var(--panel)}
.chapter-spine .chapter-index{position:relative;z-index:2;width:46px;height:46px;align-self:start;justify-self:center;display:flex;align-items:center;justify-content:center;padding:0;border-radius:50%;border:2px solid var(--line-lift);background:var(--bg);font:700 15px/1 var(--display);color:var(--muted);box-shadow:0 0 0 6px var(--bg)}
.chapter-card--done .chapter-index{background:var(--volt);border-color:var(--volt);color:var(--on-volt)}
.chapter-card--progress .chapter-index,.chapter-card--next .chapter-index{border-color:var(--volt);color:var(--volt);background:var(--panel-2);box-shadow:0 0 0 6px var(--bg),0 0 22px rgba(228,240,6,.13)}
.chapter-card--available .chapter-index{border-color:var(--volt-dim);color:var(--volt-soft)}
.chapter-card--locked{opacity:.58}
.chapter-card--locked .chapter-index{border-style:dashed}
.chapter-card--next{border-color:rgba(228,240,6,.38);box-shadow:0 18px 42px rgba(0,0,0,.23),inset 0 0 0 1px rgba(228,240,6,.04)}
.chapter-card--available{border-color:var(--line-lift)}
.chapter-state{display:inline-flex;align-items:center;min-height:28px;padding:5px 9px;border-radius:999px;border:1px solid var(--line);background:rgba(255,255,255,.018);white-space:nowrap}
.chapter-card--next .chapter-state,.chapter-card--progress .chapter-state{border-color:rgba(228,240,6,.25);background:rgba(228,240,6,.07);color:var(--volt-soft)}
.chapter-card--done .chapter-state{color:var(--text)}
@media (max-width:720px){
  .onboarding-grid{grid-template-columns:1fr}.onboarding-choice{min-height:0}
  .library-search-row{grid-template-columns:1fr}.library-deep-search{text-align:center}
  .chapter-spine{padding-left:0}.chapter-spine::before{left:23px}
  .chapter-spine .chapter-card{grid-template-columns:48px minmax(0,1fr);padding:16px 14px 16px 4px}
  .chapter-spine .chapter-index{width:40px;height:40px;box-shadow:0 0 0 5px var(--bg)}
  .chapter-top{gap:10px}.chapter-state{font-size:10px;min-height:26px}
  .home-layout>.readout{display:none}
}
@media (prefers-reduced-motion: reduce){
  .onboarding-choice,.search-result-card{transition:none}.onboarding-choice:hover,.search-result-card:hover{transform:none}
}

.loading-card{display:flex;gap:14px;align-items:center;padding:20px;border:1px solid var(--line);border-radius:22px;background:var(--panel);color:var(--muted);box-shadow:0 16px 36px rgba(0,0,0,.18)}
.loading-card strong{display:block;font:650 16px/1.3 var(--display);color:var(--text)}
.loading-card span{display:block;margin-top:3px;font-size:13px;color:var(--muted)}
.loading-mark{width:42px;height:42px;flex:0 0 42px;border-radius:14px;border:1px solid rgba(228,240,6,.18);background:linear-gradient(90deg,rgba(228,240,6,.03),rgba(228,240,6,.14),rgba(228,240,6,.03));background-size:220% 100%;animation:lighthouse-load 1.15s ease-in-out infinite}
@keyframes lighthouse-load{0%{background-position:100% 0}100%{background-position:-100% 0}}
@media (prefers-reduced-motion:reduce){.loading-mark{animation:none;background:rgba(228,240,6,.07)}}

/* ---- pass 7: actual application shell ---- */
html.lh-app{background:var(--bg);min-height:100%;-webkit-text-size-adjust:100%;text-size-adjust:100%}
body.app-shell{min-height:100dvh;min-height:var(--app-visual-height,100dvh);background:var(--bg);overflow-x:hidden;overscroll-behavior-x:none;-webkit-tap-highlight-color:transparent}
body.app-shell .app-content{min-height:calc(var(--app-visual-height,100dvh) - 1px)}
.shell-status{position:fixed;z-index:120;left:50%;top:calc(10px + env(safe-area-inset-top,0px));transform:translate(-50%,-12px);display:flex;align-items:center;gap:10px;max-width:min(92vw,520px);padding:9px 12px;border:1px solid var(--line-lift);border-radius:999px;background:color-mix(in srgb,var(--panel-2) 94%,transparent);color:var(--text);font:600 12px/1.2 var(--sans);box-shadow:0 14px 38px rgba(0,0,0,.38);backdrop-filter:blur(18px);opacity:0;pointer-events:none;transition:opacity .2s ease,transform .2s ease}
.shell-status.show{opacity:1;transform:translate(-50%,0);pointer-events:auto}
.shell-status button{min-height:30px;padding:5px 9px;border-radius:999px;border:1px solid rgba(228,240,6,.28);background:rgba(228,240,6,.1);color:var(--volt);font:600 11px/1 var(--sans)}
html[data-online="false"] .beacon{opacity:.22}
body.shell-navigating .app-content{opacity:.92;transform:translateY(1px)}
body.shell-leaving .app-content{pointer-events:none}
body.app-shell .app-content{transition:opacity .12s ease,transform .12s ease}

.app-install-row{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:14px 15px;margin:14px 0 0;border:1px solid var(--line);border-radius:16px;background:rgba(255,255,255,.018)}
.app-install-copy{display:flex;flex-direction:column;gap:3px;min-width:0}.app-install-copy strong{font-size:14px}.app-install-copy span{font-size:12px;color:var(--muted);line-height:1.45}
.app-installed-badge{display:inline-flex;align-items:center;justify-content:center;min-height:34px;padding:7px 10px;border:1px solid rgba(228,240,6,.22);border-radius:999px;color:var(--volt);background:rgba(228,240,6,.07);font:600 11px/1 var(--sans);white-space:nowrap}

@media (max-width:720px){
  body.app-shell{padding-top:env(safe-area-inset-top,0px);padding-bottom:calc(96px + env(safe-area-inset-bottom,0px))}
  body.app-shell .wrap{padding-bottom:24px}
  body.app-shell header.learn{top:0}
  body.app-shell .bottombar{bottom:calc(8px + env(safe-area-inset-bottom,0px));padding:7px 6px}
  body.app-shell.keyboard-open{padding-bottom:12px}
  body.app-shell.keyboard-open .bottombar{opacity:0;transform:translateY(24px);pointer-events:none}
  .bottombar{transition:opacity .16s ease,transform .16s ease,border-color .16s ease}
  .app-install-row{align-items:flex-start;flex-direction:column}.app-install-row .btn{width:100%}
}
@media (display-mode:standalone){
  body.app-shell header.learn{padding-top:12px}
  body.app-shell .bottombar{box-shadow:0 14px 34px rgba(0,0,0,.46),inset 0 1px 0 rgba(255,255,255,.025)}
}
@media (prefers-reduced-motion:reduce){
  body.app-shell .app-content,.shell-status,.bottombar{transition:none!important}
}


/* ---- pass 8: big-app simplification ---- */
.theme-btn{display:inline-flex;align-items:center;justify-content:center;gap:7px;font-family:var(--sans);font-weight:700}
.theme-btn svg{width:17px;height:17px;display:block}
.session-shell{width:min(100%,760px);margin:0 auto;gap:14px}
.session-hero{padding:26px 28px}
.session-hero h1{font-size:40px;line-height:1.05;margin:6px 0 0}
.session-hero .session-pill-row{margin-top:22px}
.session-meter-card{padding:15px 18px}
.session-stage-card{padding:26px 28px;min-height:380px}
.session-plan-line{margin-top:9px;color:var(--muted);font:600 12px/1.4 var(--sans)}
.session-stage-head h2{font-size:28px;margin-top:4px}
.session-stage-head .section-copy{font-size:13px;margin-top:2px!important}
.session-flashcard{min-height:250px;font-size:22px;border-radius:24px}
.session-input-row{max-width:460px}
.session-input{font-size:20px;min-height:58px}

/* Drill is deliberately one centered task, not a dashboard. */
.drill-shell{width:min(100%,720px);margin:0 auto;display:flex;flex-direction:column;gap:14px}
.drill-top{padding:12px 2px 0}
.drill-top h1{font-size:38px;margin:4px 0 0}
.drill-filter-row{display:flex;gap:8px;overflow-x:auto;padding:3px 0 5px;scrollbar-width:none}
.drill-filter-row::-webkit-scrollbar{display:none}
.drill-filter-chip{flex:none;min-height:40px;padding:8px 14px;border-radius:999px;border:1px solid var(--line);background:var(--panel);color:var(--muted);font:650 13px/1 var(--sans)}
.drill-filter-chip.on{background:var(--volt);color:var(--on-volt);border-color:var(--volt)}
.drill-card{padding:28px;border:1px solid var(--line);border-radius:28px;background:linear-gradient(180deg,rgba(255,255,255,.025),transparent),var(--panel);box-shadow:0 22px 55px rgba(0,0,0,.28)}
.drill-meta{display:flex;justify-content:space-between;gap:10px;color:var(--muted);font:650 12px/1.3 var(--sans)}
.drill-meta span:first-child{color:var(--volt-soft)}
.drill-prompt{font:650 24px/1.35 var(--display);letter-spacing:-.02em;margin:34px 0}
.drill-answer{display:flex;flex-direction:column;gap:14px}
.drill-input-wrap{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:10px}
.drill-answer-input{min-height:62px!important;border-radius:18px!important;font:650 22px/1 var(--display)!important;padding:14px 18px!important}
.drill-unit{font:600 14px/1 var(--sans);color:var(--muted);min-width:34px}
.drill-feedback{min-height:22px;font:600 14px/1.45 var(--sans);color:var(--muted)}
.drill-feedback.ok{color:var(--volt-soft)}
.drill-feedback.warn{color:var(--amber)}
.drill-feedback.hint{color:var(--muted)}
.drill-actions{display:grid;grid-template-columns:2fr 1fr;gap:10px}
.drill-actions .btn{min-height:54px}
.drill-stats-row{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.drill-stat{padding:14px;border-radius:18px;border:1px solid var(--line);background:var(--panel);text-align:center}
.drill-stat strong{display:block;font:700 22px/1 var(--display);color:var(--text)}
.drill-stat span{display:block;margin-top:5px;font:650 10px/1 var(--sans);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}

@media (min-width:721px){
  .session-shell{padding-top:4px}
  .session-hero,.session-meter-card,.session-stage-card{width:100%}
}

@media (max-width:720px){
  header.learn{align-items:center}
  header.learn .brand-lockup{min-width:0}
  header.learn nav{margin-left:auto;display:flex}
  header.learn nav a{display:none}
  header.learn .theme-btn{display:inline-flex!important;min-width:74px;min-height:40px;padding:8px 11px;border-radius:14px;background:var(--panel);color:var(--text)}
  .session-shell{gap:10px}
  .session-hero{padding:18px 18px 16px;border-radius:24px}
  .session-hero h1{font-size:31px}
  .session-hero .hero-copy{display:none}
  .session-pill-row{grid-template-columns:repeat(3,1fr)!important;gap:7px;margin-top:15px!important}
  .session-pill{padding:11px 8px;border-radius:16px;text-align:center;align-items:center}
  .session-pill strong{font-size:19px}
  .session-pill span{font-size:9px;letter-spacing:.05em}
  .session-meter-card{padding:12px 14px;border-radius:20px}
  .session-meter-top{font-family:var(--sans);font-size:11px}
  .session-plan-line{font-size:11px;margin-top:6px}
  .session-stage-card{padding:20px 18px;min-height:0;border-radius:24px}
  .session-stage-head{margin-bottom:15px}
  .session-stage-head h2{font-size:24px;margin:2px 0}
  .session-stage-head .section-copy{font-size:11.5px}
  .session-flashcard{min-height:220px;font-size:20px;padding:22px 18px}
  .session-input-row{display:grid;grid-template-columns:minmax(0,1fr) auto;align-items:center;width:100%;gap:8px}
  .session-input{max-width:none!important;width:100%;font-size:19px;min-height:58px}
  .cta-row{display:grid;grid-template-columns:1fr 1fr;gap:9px;width:100%}
  .cta-row>*{width:100%;justify-content:center;text-align:center}
  .session-primary-btn{width:100%}

  .drill-shell{gap:10px}
  .drill-top{padding:4px 2px 0}
  .drill-top h1{font-size:30px}
  .drill-filter-row{margin-left:-2px;margin-right:-2px}
  .drill-filter-chip{min-height:38px;padding:8px 12px;font-size:12px}
  .drill-card{padding:20px 18px;border-radius:24px}
  .drill-meta{font-size:11px}
  .drill-prompt{font-size:21px;line-height:1.38;margin:26px 0}
  .drill-answer-input{min-height:60px!important;font-size:20px!important}
  .drill-actions{grid-template-columns:1fr}
  .drill-actions .drill-check{order:1}
  .drill-actions .drill-next{order:2}
  .drill-stats-row{gap:7px}
  .drill-stat{padding:12px 6px}
  .drill-stat strong{font-size:20px}
  .drill-stat span{font-size:9px}

  /* Mobile cards should read like an app menu, not a catalog paragraph. */
  .mini-course-card p,.tool-card p,.library-card p{display:none}
  .mini-course-card,.tool-card,.library-card{min-height:82px;justify-content:center}
  .section-head .section-copy{display:none}
  .footer-silk{display:none}
}


/* ---- pass 9: visual app overhaul ---- */
body{background:var(--bg)}
body::before{content:"";position:fixed;inset:0;pointer-events:none;z-index:-1;background:radial-gradient(circle at 15% -10%,rgba(228,240,6,.08),transparent 31%),radial-gradient(circle at 100% 18%,rgba(52,92,255,.06),transparent 26%)}
:root[data-theme="day"] body::before{background:radial-gradient(circle at 12% -10%,rgba(19,65,160,.055),transparent 31%),radial-gradient(circle at 95% 10%,rgba(179,25,66,.045),transparent 26%)}

/* Product art. These are real SVG scenes, not decorative gradients. */
.app-art{--art-deep:var(--art-base-deep);--art-soft:var(--art-base-soft);--art-surface:var(--art-base-surface);--art-board:var(--art-base-board);--art-ink:var(--art-base-ink);--art-line:var(--art-base-line);--art-accent:var(--art-base-accent);--art-hot:var(--art-base-hot);--art-glow:var(--art-base-glow);overflow:hidden;min-width:0}
.app-art svg{display:block;width:100%;height:100%;object-fit:cover}
.app-art--electronics{--art-deep:var(--art-elec-deep);--art-soft:var(--art-elec-soft);--art-surface:var(--art-elec-surface);--art-board:var(--art-elec-board);--art-hot:var(--art-elec-hot)}
.app-art--mechanical{--art-deep:var(--art-mech-deep);--art-soft:var(--art-mech-soft);--art-surface:var(--art-mech-surface);--art-hot:var(--art-mech-hot)}
.app-art--manufacturing{--art-deep:var(--art-mfg-deep);--art-soft:var(--art-mfg-soft);--art-surface:var(--art-mfg-surface);--art-hot:var(--art-mfg-hot)}
.app-art--ai{--art-deep:var(--art-ai-deep);--art-soft:var(--art-ai-soft);--art-surface:var(--art-ai-surface);--art-hot:var(--art-ai-hot)}
.app-art--business{--art-deep:var(--art-biz-deep);--art-soft:var(--art-biz-soft);--art-surface:var(--art-biz-surface);--art-hot:var(--art-biz-hot)}
.app-art--reference{--art-deep:var(--art-ref-deep);--art-soft:var(--art-ref-soft);--art-surface:var(--art-ref-surface);--art-board:var(--art-ref-board);--art-hot:var(--art-ref-hot)}

.app-home{width:min(100%,1120px);margin:0 auto;display:flex;flex-direction:column;gap:30px}
.app-resume-hero{display:grid;grid-template-columns:minmax(0,1fr) minmax(330px,.82fr);min-height:430px;border-radius:34px;overflow:hidden;background:var(--panel);border:1px solid var(--line);color:var(--text);text-decoration:none;box-shadow:0 28px 80px rgba(0,0,0,.28);transition:transform .18s ease,border-color .18s ease,box-shadow .18s ease}
.app-resume-hero:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--line-lift);box-shadow:0 34px 90px rgba(0,0,0,.34)}
.app-resume-copy{display:flex;flex-direction:column;align-items:flex-start;justify-content:center;padding:48px 46px;min-width:0}
.app-eyebrow{font:750 12px/1 var(--sans);letter-spacing:.13em;text-transform:uppercase;color:var(--volt);margin-bottom:16px}
.app-resume-copy h1{font-size:50px;line-height:.98;letter-spacing:-.045em;margin:0;max-width:12ch}
.app-resume-lesson{font:650 18px/1.4 var(--sans);color:var(--muted);margin:18px 0 24px;max-width:36ch}
.app-resume-progress{display:grid;grid-template-columns:minmax(160px,300px) auto;gap:12px;align-items:center;width:100%;max-width:370px}
.app-resume-progress span{font:800 14px/1 var(--sans);color:var(--text)}
.app-progress{height:12px;background:var(--line-quiet)}
.app-hero-cta{display:inline-flex;align-items:center;justify-content:center;min-height:54px;margin-top:28px;padding:0 24px;border-radius:17px;background:var(--volt);color:var(--on-volt);font:800 15px/1 var(--sans);box-shadow:0 12px 28px rgba(228,240,6,.15)}
.app-resume-art{height:100%;min-height:430px;border-left:1px solid var(--line)}
:root[data-theme="day"] .app-hero-cta{box-shadow:0 12px 24px rgba(19,65,160,.16)}

.app-quick-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}
.app-quick-card{display:grid;grid-template-columns:64px minmax(0,1fr) auto;align-items:center;gap:15px;min-height:112px;padding:19px 20px;border-radius:26px;background:var(--panel);border:1px solid var(--line);color:var(--text);text-decoration:none;transition:transform .16s ease,border-color .16s ease,background .16s ease}
.app-quick-card:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--line-lift);background:var(--panel-lift)}
.app-action-icon{display:grid;place-items:center;width:60px;height:60px;border-radius:20px;background:var(--field);color:var(--volt)}
.app-action-icon svg{width:38px;height:38px}
.app-quick-card--today .app-action-icon{background:var(--volt);color:var(--on-volt)}
.app-quick-copy{display:flex;flex-direction:column;gap:5px;min-width:0}
.app-quick-copy span{font:700 12px/1 var(--sans);text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.app-quick-copy strong{font:750 19px/1.15 var(--display);letter-spacing:-.02em;color:var(--text)}
.app-chevron{font:500 31px/1 var(--sans);color:var(--muted)}

.app-section-title{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin-bottom:-14px}
.app-section-title>div{display:flex;align-items:baseline;gap:12px;min-width:0}
.app-section-title h2{font-size:27px;line-height:1;margin:0;letter-spacing:-.035em}
.app-section-title span{font:600 13px/1 var(--sans);color:var(--muted)}
.app-section-title>a{font:750 13px/1 var(--sans);color:var(--volt);text-decoration:none}

.app-course-rail{display:grid;grid-auto-flow:column;grid-auto-columns:minmax(250px,286px);gap:14px;overflow-x:auto;padding:2px 2px 8px;scroll-snap-type:x proximity;scrollbar-width:none}
.app-course-rail::-webkit-scrollbar{display:none}
.app-course-tile{display:block;overflow:hidden;border-radius:27px;background:var(--panel);border:1px solid var(--line);color:var(--text);text-decoration:none;scroll-snap-align:start;transition:transform .16s ease,border-color .16s ease}
.app-course-tile:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--line-lift)}
.app-course-art{height:160px;border-bottom:1px solid var(--line)}
.app-course-tile-body{padding:16px 17px 18px}
.app-course-tile-top{display:flex;justify-content:space-between;gap:8px;margin-bottom:8px;font:750 10px/1 var(--sans);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.app-course-tile-top strong{color:var(--volt)}
.app-course-tile h3{font:750 20px/1.15 var(--display);letter-spacing:-.025em;margin:0 0 16px;color:var(--text)}
.app-course-progress{height:7px}

.app-explore{display:flex;flex-direction:column;gap:26px}
.app-domain-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}
.app-domain-card{display:grid;grid-template-rows:150px auto;border-radius:27px;overflow:hidden;border:1px solid var(--line);background:var(--panel);color:var(--text);text-decoration:none;transition:transform .16s ease,border-color .16s ease}
.app-domain-card:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--line-lift)}
.app-domain-art{border-bottom:1px solid var(--line)}
.app-domain-copy{padding:17px 18px 19px}
.app-domain-copy h3{font:750 20px/1.1 var(--display);margin:0 0 7px;letter-spacing:-.025em;color:var(--text)}
.app-domain-copy p{font:550 13px/1.42 var(--sans);margin:0;color:var(--muted)}
.app-domain-copy span{display:block;margin-top:13px;font:750 12px/1 var(--sans);color:var(--volt)}

.app-library-fold{border:1px solid var(--line);border-radius:26px;background:var(--panel);overflow:hidden}
.app-library-fold>summary{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:20px 22px;cursor:pointer;list-style:none;font:750 18px/1 var(--display);color:var(--text)}
.app-library-fold>summary::-webkit-details-marker{display:none}
.app-library-fold>summary b{display:grid;place-items:center;min-width:38px;height:30px;padding:0 9px;border-radius:999px;background:var(--field);font:750 12px/1 var(--sans);color:var(--muted)}
.app-library-fold .library-browser{padding:0 18px 20px}

.app-onboarding{padding:34px;border:1px solid var(--line);border-radius:34px;background:var(--panel);box-shadow:0 28px 80px rgba(0,0,0,.25)}
.app-onboarding-head{margin-bottom:23px}.app-onboarding-head h1{font-size:46px;line-height:1;margin:0;letter-spacing:-.045em}
.app-onboarding-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px}
.app-onboarding-choice{position:relative;overflow:hidden;display:grid;grid-template-rows:130px auto;min-height:205px;border-radius:24px;border:1px solid var(--line);background:var(--field);color:var(--text);text-decoration:none}
.app-onboarding-choice:hover{text-decoration:none;border-color:var(--line-lift);transform:translateY(-2px)}
.app-onboarding-art{border-bottom:1px solid var(--line)}
.app-onboarding-choice>strong{padding:16px 42px 17px 16px;font:750 18px/1.15 var(--display);letter-spacing:-.02em;color:var(--text)}
.app-onboarding-choice>.app-chevron{position:absolute;right:16px;bottom:16px}
.app-onboarding-skip{margin-top:16px;width:100%}

/* Fast Tracks become a visual rail instead of a dense 25-item grid. */
.paths-rail-wrap{min-width:0}.paths-rail-wrap>.pr-head{display:none}
.paths-rail{display:grid;grid-auto-flow:column;grid-auto-columns:118px;gap:12px;overflow-x:auto;padding:2px 2px 8px;scrollbar-width:none;scroll-snap-type:x proximity}
.paths-rail::-webkit-scrollbar{display:none}.pr-chip{min-height:128px;border-radius:24px;padding:13px 10px;background:var(--panel);scroll-snap-align:start;border-color:var(--line)}
.pr-chip svg{width:66px;height:66px;border-radius:20px}.pr-label{font:700 11px/1.15 var(--sans);text-align:center}

/* Course pages get an image-led top instead of a text-only panel. */
.course-hero{display:grid;grid-template-columns:minmax(0,1fr) 340px;padding:0!important;overflow:hidden}
.course-hero-main{padding:30px 32px}.course-hero-art{min-height:300px;border-left:1px solid var(--line)}
.course-hero .hero-copy{font-size:14px;line-height:1.5;max-width:55ch}.course-hero .course-sub{font-size:16px}

/* Today is one coherent practice surface on desktop and mobile. */
.practice-shell{width:min(100%,820px);margin:0 auto;display:flex;flex-direction:column;gap:14px}
.practice-head{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:end;padding:8px 4px 4px}
.practice-head h1{font-size:44px;line-height:1;margin:0;letter-spacing:-.045em}.practice-head p{margin:8px 0 0;color:var(--muted);font:600 13px/1.4 var(--sans)}
.practice-count{font:800 15px/1 var(--sans);color:var(--muted)}.practice-count strong{font-size:32px;color:var(--text);margin-right:4px}
.practice-phases{display:grid;grid-template-columns:repeat(3,1fr);gap:9px}
.practice-phase{display:flex;align-items:center;gap:10px;min-height:58px;padding:10px 13px;border-radius:18px;border:1px solid var(--line);background:var(--panel);color:var(--muted)}
.practice-phase b{font:800 13px/1 var(--sans);color:var(--text)}.practice-phase span{font:700 11px/1 var(--sans)}
.practice-phase::before{content:"";width:10px;height:10px;border-radius:999px;background:var(--line-lift);box-shadow:0 0 0 5px var(--field)}
.practice-phase.on{border-color:color-mix(in srgb,var(--volt) 35%,var(--line));background:color-mix(in srgb,var(--volt) 5%,var(--panel))}.practice-phase.on::before{background:var(--volt)}
.practice-phase.done::before{background:var(--volt-soft)}
.practice-meter{padding:0 2px}.practice-meter .progressbar{height:10px}
.practice-card{min-height:430px;padding:30px;border:1px solid var(--line);border-radius:30px;background:var(--panel);box-shadow:0 24px 64px rgba(0,0,0,.24)}
.practice-card .session-stage-head{margin-bottom:20px}.practice-card .session-stage-head h2{font-size:31px}
.practice-card .hero-copy{font-size:20px;line-height:1.45;color:var(--text);max-width:34ch;margin:28px 0}
.practice-card .session-input-row{max-width:100%;grid-template-columns:minmax(0,1fr) auto}.practice-card .session-input{min-height:66px;font-size:24px}
.practice-card .cta-row{margin-top:18px}.practice-card .cta-row .btn{min-height:56px}

/* Drill: less dashboard, more full-screen exercise. */
.drill-top{display:flex;align-items:end;justify-content:space-between;gap:12px}.drill-top h1{font-size:42px}.drill-top::after{content:"Practice";font:750 11px/1 var(--sans);letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.drill-card{min-height:470px;display:flex;flex-direction:column;justify-content:center;padding:36px 38px}
.drill-prompt{font-size:29px;max-width:28ch}.drill-answer-input{min-height:70px!important;font-size:25px!important}.drill-actions .btn{min-height:58px}
.drill-stats-row{grid-template-columns:repeat(3,max-content);justify-content:center}.drill-stat{min-width:96px;background:transparent;border:0}.drill-stat span{font-family:var(--sans)}

@media (max-width:900px){
  .app-resume-hero{grid-template-columns:1fr;min-height:0}.app-resume-art{order:-1;min-height:250px;height:250px;border-left:0;border-bottom:1px solid var(--line)}.app-resume-copy{padding:30px}
  .app-domain-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.course-hero{grid-template-columns:1fr}.course-hero-art{order:-1;min-height:240px;height:240px;border-left:0;border-bottom:1px solid var(--line)}
}
@media (max-width:720px){
  .app-home{gap:24px}.wrap{padding-left:12px;padding-right:12px}
  .app-resume-hero{border-radius:28px}.app-resume-art{height:210px;min-height:210px}.app-resume-copy{padding:24px 21px 22px}.app-resume-copy h1{font-size:36px;max-width:14ch}.app-resume-lesson{font-size:15px;margin:12px 0 18px}.app-hero-cta{width:100%;margin-top:20px;min-height:52px}
  .app-quick-grid{grid-template-columns:1fr;gap:9px}.app-quick-card{min-height:86px;grid-template-columns:52px minmax(0,1fr) auto;padding:14px 15px;border-radius:21px}.app-action-icon{width:50px;height:50px;border-radius:16px}.app-action-icon svg{width:31px;height:31px}.app-quick-copy strong{font-size:18px}
  .app-section-title{margin-bottom:-10px}.app-section-title h2{font-size:23px}.app-section-title>div>span{display:none}.app-section-title>a{font-size:12px}
  .app-course-rail{grid-auto-columns:78vw;gap:11px;margin-right:-12px;padding-right:12px}.app-course-art{height:150px}.app-course-tile{border-radius:24px}
  .app-domain-grid{grid-template-columns:1fr 1fr;gap:9px}.app-domain-card{grid-template-rows:104px auto;border-radius:22px}.app-domain-copy{padding:13px}.app-domain-copy h3{font-size:17px}.app-domain-copy p{display:none}.app-domain-copy span{font-size:11px;margin-top:9px}
  .app-library-fold{border-radius:22px}.app-library-fold>summary{padding:18px;font-size:17px}
  .app-onboarding{padding:22px 16px;border-radius:28px}.app-onboarding-head h1{font-size:34px}.app-onboarding-grid{grid-template-columns:1fr 1fr;gap:9px}.app-onboarding-choice{grid-template-rows:100px auto;min-height:165px;border-radius:20px}.app-onboarding-choice>strong{font-size:15px;padding:13px 34px 14px 13px}.app-onboarding-choice>.app-chevron{right:12px;bottom:13px}
  .paths-rail{grid-auto-columns:105px;margin-right:-12px;padding-right:12px}.pr-chip{min-height:116px;border-radius:21px}.pr-chip svg{width:58px;height:58px}
  .course-hero-main{padding:22px 19px}.course-hero-art{height:190px;min-height:190px}.course-hero .hero-copy{display:none}
  .practice-shell{gap:10px}.practice-head{padding:2px 2px 6px}.practice-head h1{font-size:34px}.practice-head p{display:none}.practice-count strong{font-size:27px}.practice-phases{gap:6px}.practice-phase{min-height:50px;padding:8px;border-radius:15px;justify-content:center}.practice-phase::before{width:8px;height:8px;box-shadow:none}.practice-phase b{font-size:11px}.practice-phase span{display:none}.practice-card{min-height:0;padding:21px 18px;border-radius:25px}.practice-card .session-stage-head h2{font-size:25px}.practice-card .hero-copy{font-size:18px;margin:22px 0}.practice-card .session-input{min-height:62px;font-size:21px}
  .drill-top h1{font-size:32px}.drill-top::after{display:none}.drill-card{min-height:420px;padding:26px 18px}.drill-prompt{font-size:24px;margin:30px 0}.drill-stats-row{grid-template-columns:repeat(3,1fr)}.drill-stat{min-width:0}
}
@media (prefers-reduced-motion:reduce){.app-resume-hero,.app-quick-card,.app-course-tile,.app-domain-card,.app-onboarding-choice{transition:none}}

/* pass 9 small control fixes */
.drill-topic-select{width:auto;min-width:180px;max-width:280px;height:48px;padding:0 40px 0 15px;border-radius:15px;border:1px solid var(--line);background:var(--panel);color:var(--text);font:700 13px/1 var(--sans)}
:root[data-theme="day"] .brand-mark{border-color:rgba(19,65,160,.18);background:var(--day-pale);color:var(--day-blue);box-shadow:0 8px 20px rgba(10,49,97,.08)}
:root[data-theme="day"] header.learn nav a:hover,:root[data-theme="day"] header.learn nav a.on{border-color:rgba(19,65,160,.15);background:rgba(19,65,160,.06)}
:root[data-theme="day"] .bb-item.on{background:rgba(19,65,160,.08);color:var(--day-navy)}
:root[data-theme="day"] .progressbar i{background:linear-gradient(90deg,var(--day-blue),var(--day-navy))}
:root[data-theme="day"] .app-eyebrow,:root[data-theme="day"] .app-section-title>a,:root[data-theme="day"] .app-course-tile-top strong,:root[data-theme="day"] .app-domain-copy span{color:var(--day-blue)}
@media(max-width:720px){.drill-topic-select{min-width:0;max-width:155px;height:42px;padding-left:12px;font-size:12px}}
.review-mini-meta{display:flex;justify-content:space-between;gap:12px;padding:0 3px;color:var(--muted);font:700 12px/1 var(--sans)}
.review-practice .practice-card{display:flex;flex-direction:column;justify-content:center}
@media(max-width:720px){.review-mini-meta{font-size:11px}.review-practice .practice-card{min-height:390px}}
.app-tools-fold .tool-grid{padding:0 18px 20px}.app-fold-tool-grid{grid-template-columns:repeat(3,minmax(0,1fr))}
@media(max-width:720px){.app-fold-tool-grid{grid-template-columns:1fr 1fr}.app-tools-fold .tool-card{min-height:74px;padding:14px}.app-tools-fold .tool-card p{display:none}}


/* ---- pass 10: builder-brilliant home refinement ---- */
:root[data-theme="day"] .app-art{box-shadow:inset 0 1px 0 rgba(255,255,255,.85)}
:root[data-theme="day"] .app-course-tile,
:root[data-theme="day"] .app-domain-card,
:root[data-theme="day"] .path-feature-card,
:root[data-theme="day"] .app-quick-card,
:root[data-theme="day"] .app-resume-hero,
:root[data-theme="day"] .app-library-fold{box-shadow:0 12px 30px rgba(10,49,97,.06)}

.app-home{gap:34px}
.app-section-title{align-items:center;margin-bottom:2px}
.app-section-title>div{gap:10px}
.app-section-title h2{font-size:30px}
.app-section-title span{font-size:14px}
.app-section-cta{display:inline-flex;align-items:center;justify-content:center;min-height:40px;padding:0 15px;border:1px solid var(--line);border-radius:999px;background:var(--panel);font:750 13px/1 var(--sans);color:var(--text);text-decoration:none;position:relative;z-index:2;box-shadow:0 8px 20px rgba(0,0,0,.08)}
.app-section-cta:hover{text-decoration:none;border-color:var(--line-lift);background:var(--panel-lift)}

.app-course-rail{grid-auto-columns:minmax(300px,344px);gap:16px;padding:2px 2px 10px}
.app-course-art{height:188px}
.app-course-tile-body{padding:18px 18px 20px}
.app-course-tile h3{font-size:22px}

.path-feature-rail{display:grid;grid-auto-flow:column;grid-auto-columns:minmax(280px,340px);gap:16px;overflow-x:auto;padding:2px 2px 10px;scroll-snap-type:x proximity;scrollbar-width:none}
.path-feature-rail::-webkit-scrollbar{display:none}
.path-feature-card{display:grid;grid-template-rows:190px auto;overflow:hidden;border-radius:30px;background:var(--panel);border:1px solid var(--line);color:var(--text);text-decoration:none;scroll-snap-align:start;transition:transform .16s ease,border-color .16s ease,box-shadow .16s ease;box-shadow:0 16px 40px rgba(0,0,0,.14)}
.path-feature-card:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--line-lift);box-shadow:0 20px 46px rgba(0,0,0,.18)}
.path-feature-art{border-bottom:1px solid var(--line)}
.path-feature-body{padding:18px 18px 20px}
.path-feature-kicker{font:750 11px/1 var(--sans);letter-spacing:.1em;text-transform:uppercase;color:var(--volt);margin-bottom:10px}
.path-feature-body h3{margin:0;font:780 24px/1.06 var(--display);letter-spacing:-.03em;color:var(--text)}
.path-feature-body p{margin:11px 0 16px;font:560 14px/1.45 var(--sans);color:var(--muted);min-height:60px}
.path-feature-cta{display:inline-flex;align-items:center;min-height:38px;padding:0 14px;border-radius:999px;background:var(--field);font:750 12px/1 var(--sans);color:var(--text)}

.app-domain-grid{gap:16px}
.app-domain-card{grid-template-rows:168px auto}
.app-domain-copy h3{font-size:22px}

.app-library-fold>summary{min-height:86px}
.app-tools-fold summary,.app-library-fold summary{font-size:20px}

@media (max-width:720px){
  .app-home{gap:26px}
  .app-section-title{margin-bottom:4px}
  .app-section-title h2{font-size:24px}
  .app-section-cta{min-height:34px;padding:0 12px;font-size:12px}
  .app-course-rail{grid-auto-columns:84vw;gap:12px;margin-right:-12px;padding-right:12px}
  .app-course-art{height:174px}
  .path-feature-rail{grid-auto-columns:80vw;gap:12px;margin-right:-12px;padding-right:12px}
  .path-feature-card{grid-template-rows:166px auto;border-radius:26px}
  .path-feature-body{padding:16px 16px 18px}
  .path-feature-body h3{font-size:22px}
  .path-feature-body p{display:block;font-size:13px;min-height:54px}
  .app-domain-grid{grid-template-columns:1fr 1fr;gap:10px}
  .app-domain-card{grid-template-rows:118px auto}
}


/* ---- pass 11: premium app chrome and day-theme purge ---- */
/* The brand lockup must stay horizontal. An older header rule stacked .mark. */
header.learn .brand-lockup{flex-direction:row!important;align-items:center!important}
header.learn .brand-type{min-width:0}

/* Day mode is strictly Lighthouse red/white/blue. Override all surviving
   volt-tinted decorative treatments that otherwise read yellow/olive. */
:root[data-theme="day"] button.primary,
:root[data-theme="day"] .btn.primary{box-shadow:0 8px 22px rgba(19,65,160,.14)}
:root[data-theme="day"] .hero-card--glow::before,
:root[data-theme="day"] .course-hero::before,
:root[data-theme="day"] .lesson-pagehead::before,
:root[data-theme="day"] .session-hero::before,
:root[data-theme="day"] .search-hero::before{background:radial-gradient(circle,rgba(19,65,160,.12),rgba(19,65,160,0) 70%)}
:root[data-theme="day"] .pct-badge{background:rgba(19,65,160,.07);border-color:rgba(19,65,160,.18);color:var(--day-blue)}
:root[data-theme="day"] .chapter-card--progress,
:root[data-theme="day"] .chapter-card--next{border-color:rgba(19,65,160,.2);background:linear-gradient(180deg,rgba(19,65,160,.035),rgba(19,65,160,0)),var(--panel)}
:root[data-theme="day"] .lesson-stagebar .st.done{border-color:rgba(19,65,160,.22);color:var(--day-blue)}
:root[data-theme="day"] .session-flashcard{background:linear-gradient(180deg,rgba(19,65,160,.025),rgba(255,255,255,0)),var(--field)}
:root[data-theme="day"] .session-grade.good{border-color:rgba(19,65,160,.22);background:rgba(19,65,160,.045)}
:root[data-theme="day"] .session-input:focus,
:root[data-theme="day"] .library-search-input:focus,
:root[data-theme="day"] .global-search-input:focus{box-shadow:0 0 0 3px rgba(19,65,160,.08)}
:root[data-theme="day"] .q .fb.ok{background:rgba(19,65,160,.04)}
:root[data-theme="day"] .badge-tile.earned,
:root[data-theme="day"] .reveal-panel,
:root[data-theme="day"] .onboarding-choice:hover,
:root[data-theme="day"] .library-filter-chip.on,
:root[data-theme="day"] .app-installed-badge{border-color:rgba(19,65,160,.2);background:rgba(19,65,160,.045)}
:root[data-theme="day"] .chapter-spine::before{background:linear-gradient(180deg,rgba(19,65,160,.24),var(--line) 36%,var(--line))}
:root[data-theme="day"] .chapter-card--progress .chapter-index,
:root[data-theme="day"] .chapter-card--next .chapter-index{box-shadow:0 0 0 6px var(--bg),0 0 22px rgba(19,65,160,.1)}
:root[data-theme="day"] .chapter-card--next{border-color:rgba(19,65,160,.28)}
:root[data-theme="day"] .chapter-card--next .chapter-state,
:root[data-theme="day"] .chapter-card--progress .chapter-state{border-color:rgba(19,65,160,.2);background:rgba(19,65,160,.055);color:var(--day-blue)}
:root[data-theme="day"] .loading-mark{border-color:rgba(19,65,160,.16);background:linear-gradient(90deg,rgba(19,65,160,.02),rgba(19,65,160,.10),rgba(19,65,160,.02))}
:root[data-theme="day"] .shell-status button{border-color:rgba(19,65,160,.22);background:rgba(19,65,160,.06);color:var(--day-blue)}

/* Mobile app chrome: one compact top bar, not a website masthead. */
@media(max-width:720px){
  body{padding-bottom:calc(94px + env(safe-area-inset-bottom,0px))}
  header.learn{min-height:58px;margin-bottom:12px;padding:6px 2px 8px!important;background:color-mix(in srgb,var(--bg) 92%,transparent);border-bottom:1px solid color-mix(in srgb,var(--line) 72%,transparent)}
  header.learn .brand-lockup{gap:8px!important;flex:1 1 auto}
  .brand-mark{width:36px!important;height:36px!important;border-radius:11px!important;flex:0 0 36px}
  .brand-mark svg{width:22px!important;height:22px!important}
  .brand-type{justify-content:center}
  header.learn .brand-type a{font-size:16px!important;line-height:1.05;white-space:nowrap}
  .mark-sub{display:none!important}
  header.learn nav{flex:0 0 auto;margin-left:6px}
  header.learn .theme-btn{min-width:66px!important;min-height:36px!important;padding:6px 10px!important;border-radius:999px!important;font-size:12px!important;background:var(--panel)!important}
  .bottombar{left:14px;right:14px;bottom:calc(10px + env(safe-area-inset-bottom,0px));padding:8px 7px;border-radius:27px;box-shadow:0 18px 44px rgba(0,0,0,.22)}
  .bb-item{min-height:58px;border-radius:18px;justify-content:center}
  .bb-glyph,.bb-glyph svg{width:22px;height:22px}
  .bb-label{font-size:10.5px}
}

/* Make course-specific art read like a focal object rather than a banner. */
.app-course-art,.app-domain-art,.path-feature-art,.course-hero-art{background:var(--board)}
.app-course-art svg,.app-domain-art svg,.path-feature-art svg,.course-hero-art svg{transform:scale(1.01)}

/* ---- pass 12: learning experience overhaul ---- */
.lesson-pagehead--visual{display:grid;grid-template-columns:minmax(0,1fr) minmax(300px,.86fr);padding:0!important;overflow:hidden;min-height:330px}
.lesson-pagehead-copy{padding:30px 32px;display:flex;flex-direction:column;justify-content:center;min-width:0}
.lesson-pagehead-copy h1{font-size:44px;line-height:1.02;letter-spacing:-.045em;margin:16px 0 10px;max-width:13ch}
.lesson-chapter-label{margin:0 0 15px;color:var(--muted);font:650 14px/1.35 var(--sans)}
.lesson-hero-art{min-height:330px;border-left:1px solid var(--line)}
.lesson-pagehead--visual::before{display:none}
.lesson-pagehead .bookref--hero{margin:0;padding:0;font:600 12px/1.4 var(--sans);color:var(--muted)}
.lesson-pill-row{margin-top:14px}
.lesson-pill{font-size:11px;padding:7px 10px}

.lesson-stagebar{position:relative;display:grid;grid-template-columns:repeat(5,1fr);gap:6px;margin:14px auto 16px;width:min(100%,760px)}
.lesson-stagebar .st{min-height:38px;border-radius:999px;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.04em;background:var(--field)}
.lesson-stagebar .st.on{box-shadow:0 8px 22px rgba(228,240,6,.13)}

.lesson-focus.panel{width:min(100%,860px);margin:0 auto;padding:0;border:0;background:transparent;box-shadow:none}
.lesson-card{display:flex;flex-direction:column;gap:16px}
.lesson-pager{min-width:0}
.lesson-concept-top{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:2px 4px}
.lesson-concept-count{font:800 12px/1 var(--sans);letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.lesson-concept-dots{display:flex;align-items:center;gap:6px;flex:1;justify-content:flex-end}
.lesson-concept-dots span{width:22px;height:5px;border-radius:999px;background:var(--line)}
.lesson-concept-dots span.done{background:var(--volt-dim)}
.lesson-concept-dots span.on{width:34px;background:var(--volt)}
.lesson-concept-art{height:300px;border-radius:30px;border:1px solid var(--line);box-shadow:0 24px 60px rgba(0,0,0,.22)}
.lesson-concept-art svg{border-radius:29px}

.lesson-concept-card{position:relative;padding:28px 30px 30px;border:1px solid var(--line);border-radius:30px;background:var(--panel);box-shadow:0 20px 54px rgba(0,0,0,.18)}
.lesson-concept-head{display:flex;align-items:flex-start;justify-content:space-between;gap:14px;margin-bottom:8px}
.lesson-concept-head h2{font-size:32px;line-height:1.05;letter-spacing:-.035em;margin:0;max-width:19ch}
.lesson-concept-head h2:before{display:none}
.lesson-section-copy{margin-top:18px}
.lesson-section-copy p{font-size:18px;line-height:1.66;max-width:61ch;margin:0 0 18px}
.lesson-section-copy p:last-child{margin-bottom:0}
.lesson-listen-btn{margin-top:12px;min-height:38px;padding:7px 12px;align-self:flex-start}

.lesson-study-tools{margin-left:auto;position:relative}
.lesson-study-tools>summary{list-style:none;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:0 13px;border:1px solid var(--line);border-radius:999px;background:var(--field);font:750 11px/1 var(--sans);color:var(--muted)}
.lesson-study-tools>summary::-webkit-details-marker{display:none}
.lesson-study-tools[open]>summary{color:var(--text);border-color:var(--line-lift)}
.lesson-study-tools-body{margin-top:10px;padding:12px;border:1px solid var(--line);border-radius:18px;background:var(--field);display:flex;flex-direction:column;gap:8px;min-width:220px}
.lesson-study-tools-body .sec-tools{margin:0!important;display:flex;gap:7px;flex-wrap:wrap}
.lesson-study-tools-body button{font-size:11px;min-height:36px}

.lesson-concept-sim{margin:0;border-radius:28px;padding:18px;background:var(--panel);box-shadow:0 18px 46px rgba(0,0,0,.16)}
.lesson-checkpoint-label{font:800 12px/1 var(--sans);letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin:10px 4px -4px}
.lesson-pager>.q{margin:0;border-radius:28px;padding:25px 26px;background:var(--panel);box-shadow:0 18px 46px rgba(0,0,0,.16)}
.lesson-pager>.q .prompt{font-size:22px;line-height:1.4;margin-bottom:18px}
.lesson-pager>.q .conf{margin:18px 0;gap:8px}
.lesson-pager>.q .conf .label{width:100%;font:700 11px/1 var(--sans);text-transform:uppercase;letter-spacing:.08em}
.lesson-pager>.q .conf button{flex:1;min-height:46px;border-radius:14px;font-family:var(--sans);font-weight:750}
.lesson-pager>.q .opts{gap:10px}
.lesson-pager>.q .opts button{min-height:54px;border-radius:16px;padding:12px 15px;font-size:16px}
.lesson-pager>.q>div:last-child button.primary{min-width:160px;min-height:52px;border-radius:16px}
.q--complete{opacity:.8}

.lesson-concept-nav{display:grid;grid-template-columns:auto minmax(180px,1fr);gap:10px;align-items:center;padding:4px 0 6px}
.lesson-concept-nav button{min-height:56px;border-radius:18px;font-family:var(--sans);font-weight:800}
.lesson-nav-next{justify-self:stretch}
.lesson-nav-back{min-width:100px}

.lesson-stage-intro{padding:28px 30px;border:1px solid var(--line);border-radius:28px;background:var(--panel);margin-bottom:14px}
.lesson-stage-intro h2{font-size:34px;letter-spacing:-.04em;margin:8px 0 8px}
.lesson-stage-intro h2:before{display:none}
.lesson-stage-intro p{margin:0;color:var(--muted);font:600 15px/1.5 var(--sans);max-width:46ch}

/* Assessment stages should also feel like app activities, not form pages. */
.lesson-focus>.q{border-radius:28px;padding:25px 26px;background:var(--panel);box-shadow:0 18px 46px rgba(0,0,0,.16)}
.lesson-focus>.q .prompt{font-size:21px;line-height:1.4}
.lesson-focus textarea{min-height:220px;border-radius:22px;padding:18px;font-family:var(--sans);font-size:17px;line-height:1.55;background:var(--panel)}
.lesson-focus>div>button.primary,.lesson-focus>.primary{min-height:54px;border-radius:17px;font-family:var(--sans);font-weight:800}

:root[data-theme="day"] .lesson-stagebar .st.on{box-shadow:0 8px 22px rgba(19,65,160,.12)}
:root[data-theme="day"] .lesson-concept-dots span.done{background:var(--lesson-done)}
:root[data-theme="day"] .lesson-concept-dots span.on{background:var(--day-blue)}
:root[data-theme="day"] .lesson-concept-art,
:root[data-theme="day"] .lesson-concept-card,
:root[data-theme="day"] .lesson-pager>.q,
:root[data-theme="day"] .lesson-stage-intro{box-shadow:0 14px 34px rgba(10,49,97,.07)}

@media(max-width:900px){
  .lesson-pagehead--visual{grid-template-columns:1fr;min-height:0}
  .lesson-hero-art{order:-1;height:220px;min-height:220px;border-left:0;border-bottom:1px solid var(--line)}
  .lesson-pagehead-copy{padding:22px 22px 24px}
  .lesson-pagehead-copy h1{font-size:37px;max-width:15ch}
}

@media(max-width:720px){
  .lesson-pagehead--visual{border-radius:27px;margin-bottom:10px}
  .lesson-hero-art{height:176px;min-height:176px}
  .lesson-pagehead-copy{padding:18px 18px 20px}
  .lesson-pagehead-copy h1{font-size:31px;margin:12px 0 8px;max-width:17ch}
  .lesson-chapter-label{font-size:12px;margin-bottom:10px}
  .lesson-pagehead .bookref--hero{font-size:11px}
  .lesson-pill-row{margin-top:10px}
  .lesson-pill{font-size:9px;padding:6px 8px}

  .lesson-stagebar{grid-template-columns:repeat(5,1fr);gap:5px;margin:8px 0 12px}
  .lesson-stagebar .st{min-height:28px;padding:0;border-radius:999px;font-size:0;color:transparent}
  .lesson-stagebar .st::after{content:"";display:block;width:8px;height:8px;border-radius:50%;background:currentColor}
  .lesson-stagebar .st{color:var(--muted)}
  .lesson-stagebar .st.on{color:var(--on-volt)}
  .lesson-stagebar .st.done{color:var(--volt-dim)}

  .lesson-focus.panel{padding:0!important}
  .lesson-card{gap:11px}
  .lesson-concept-top{padding:1px 2px}
  .lesson-concept-count{font-size:10px}
  .lesson-concept-dots{gap:4px}
  .lesson-concept-dots span{width:14px;height:4px}.lesson-concept-dots span.on{width:24px}
  .lesson-concept-art{height:204px;border-radius:25px}
  .lesson-concept-art svg{border-radius:24px}
  .lesson-concept-card{padding:21px 18px 22px;border-radius:25px}
  .lesson-concept-head{display:flex;flex-direction:row;align-items:flex-start}
  .lesson-concept-head h2{font-size:27px;max-width:13ch}
  .lesson-section-copy{margin-top:14px}
  .lesson-section-copy p{font-size:17px;line-height:1.62;margin-bottom:16px}
  .lesson-study-tools{margin-left:auto}
  .lesson-study-tools>summary{font-size:0;width:38px;padding:0;border-radius:13px}
  .lesson-study-tools>summary::after{content:"•••";font-size:14px;letter-spacing:2px;color:var(--muted)}
  .lesson-study-tools-body{position:absolute;right:0;z-index:12;width:min(280px,78vw);box-shadow:0 18px 44px rgba(0,0,0,.24)}
  .lesson-concept-sim{padding:13px;border-radius:24px}
  .lesson-pager>.q,.lesson-focus>.q{padding:20px 17px;border-radius:24px}
  .lesson-pager>.q .prompt,.lesson-focus>.q .prompt{font-size:19px}
  .lesson-pager>.q .conf button{min-height:44px;padding:8px 4px;font-size:12px}
  .lesson-pager>.q .opts button{min-height:52px;font-size:15px}
  .lesson-concept-nav{position:sticky;bottom:calc(82px + env(safe-area-inset-bottom,0px));z-index:15;margin:3px -2px 0;padding:8px;border:1px solid var(--line);border-radius:22px;background:color-mix(in srgb,var(--bg) 92%,transparent);backdrop-filter:blur(18px);box-shadow:0 12px 34px rgba(0,0,0,.22)}
  .lesson-concept-nav button{min-height:50px;border-radius:15px}
  .lesson-nav-back{min-width:78px}
  .lesson-stage-intro{padding:22px 19px;border-radius:25px}
  .lesson-stage-intro h2{font-size:29px}
}

/* pass 12: pretest and completion as app states */
.pretest-progress{padding:16px 18px;border:1px solid var(--line);border-radius:22px;background:var(--panel);margin-bottom:14px}
.pretest-progress-copy{display:flex;align-items:baseline;justify-content:space-between;gap:12px}
.pretest-progress-copy strong{font:800 21px/1 var(--display);color:var(--text)}
.pretest-progress-copy span{font:700 11px/1 var(--sans);text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.pretest-progress .progressbar{height:9px;margin:11px 0 0}
.lesson-stage-action{display:flex;justify-content:flex-end;margin-top:12px}
.lesson-start-btn{min-width:220px;min-height:58px;border-radius:18px;font-family:var(--sans);font-weight:800}

.lesson-complete-screen{overflow:hidden;border:1px solid var(--line);border-radius:32px;background:var(--panel);box-shadow:0 24px 64px rgba(0,0,0,.22)}
.lesson-complete-art{height:285px;border-bottom:1px solid var(--line)}
.lesson-complete-copy{padding:28px 30px 32px}
.lesson-complete-copy h2{font-size:36px;line-height:1.04;letter-spacing:-.04em;margin:9px 0 22px}
.lesson-complete-copy h2:before{display:none}
.lesson-complete-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin:0 0 20px}
.lesson-complete-stats>div{padding:15px;border-radius:19px;background:var(--field);border:1px solid var(--line);display:flex;flex-direction:column;gap:5px}
.lesson-complete-stats strong{font:820 24px/1 var(--display);color:var(--text)}
.lesson-complete-stats span{font:700 10px/1.2 var(--sans);text-transform:uppercase;letter-spacing:.07em;color:var(--muted)}
.lesson-complete-copy>p{margin:0;color:var(--muted);font:600 15px/1.5 var(--sans);max-width:48ch}
.lesson-complete-actions{display:grid;grid-template-columns:1.4fr 1fr;gap:10px;margin-top:22px}
.lesson-complete-actions .btn{display:flex;align-items:center;justify-content:center;min-height:56px;border-radius:17px;font-family:var(--sans);font-weight:800}
.lesson-path-next{margin-top:14px;padding:24px;border:1px solid var(--line);border-radius:26px;background:var(--panel)}
.lesson-path-next h3{font-size:25px;letter-spacing:-.03em;margin:7px 0 8px}.lesson-path-next p{color:var(--muted);font-size:14px;line-height:1.5}.lesson-path-next .btn{margin-top:8px}
:root[data-theme="day"] .lesson-complete-screen,:root[data-theme="day"] .pretest-progress{box-shadow:0 14px 34px rgba(10,49,97,.07)}

@media(max-width:720px){
  .pretest-progress{padding:14px 15px;border-radius:20px}
  .lesson-stage-action{display:block}.lesson-start-btn{width:100%;min-width:0}
  .lesson-complete-screen{border-radius:27px}
  .lesson-complete-art{height:190px}
  .lesson-complete-copy{padding:22px 18px 23px}
  .lesson-complete-copy h2{font-size:30px;margin-bottom:17px}
  .lesson-complete-stats{gap:7px}.lesson-complete-stats>div{padding:12px 10px;border-radius:16px}.lesson-complete-stats strong{font-size:21px}.lesson-complete-stats span{font-size:8px}
  .lesson-complete-actions{grid-template-columns:1fr;gap:8px}
  .lesson-path-next{padding:20px 18px;border-radius:23px}
}


/* ---- pass 13: stronger day-mode cleanup + premium icon polish ---- */
:root[data-theme="day"] .brand-mark{border-color:rgba(19,65,160,.16);background:linear-gradient(180deg,rgba(19,65,160,.06),rgba(19,65,160,.015));box-shadow:0 10px 24px rgba(10,49,97,.10), inset 0 1px 0 rgba(255,255,255,.88)}
:root[data-theme="day"] .profile-hero::before,
:root[data-theme="day"] .personal-hero::before,
:root[data-theme="day"] .tools-hero::before,
:root[data-theme="day"] .about-hero::before{background:radial-gradient(circle,rgba(19,65,160,.10),rgba(19,65,160,0) 72%)}
:root[data-theme="day"] .rail-orb{background:rgba(19,65,160,.055)!important;border-color:rgba(19,65,160,.18)!important;box-shadow:none!important}
:root[data-theme="day"] .rail-orb strong,
:root[data-theme="day"] .profile-card .section-kicker,
:root[data-theme="day"] .profile-note strong,
:root[data-theme="day"] .badge-meta,
:root[data-theme="day"] .track-card strong{color:var(--day-blue)}
:root[data-theme="day"] .badge-tile.earned .badge-icon{background:var(--day-blue);border-color:var(--day-blue);color:#fff}
:root[data-theme="day"] .track-card{border-left-color:var(--day-red)}
:root[data-theme="day"] .lesson-stagebar .st.done,
:root[data-theme="day"] .lesson-concept-dots span.done{background:var(--day-red);color:#fff;border-color:rgba(179,25,66,.22)}
:root[data-theme="day"] .lesson-concept-dots span.on{background:var(--day-blue)}
:root[data-theme="day"] .shell-status{border-color:rgba(19,65,160,.18)}

/* --- pass 13 refinements --- */
:root[data-theme="day"] .rail-orb strong{color:var(--day-blue)}
:root[data-theme="day"] .rail-orb{background:linear-gradient(180deg,rgba(19,65,160,.07),rgba(19,65,160,.02));border-color:rgba(19,65,160,.18)}
:root[data-theme="day"] .badge-tile.earned .badge-icon{background:var(--day-blue);border-color:var(--day-blue);color:#fff}
:root[data-theme="day"] .badge-icon,:root[data-theme="day"] .profile-metric,:root[data-theme="day"] .profile-stat-tile,:root[data-theme="day"] .profile-card,:root[data-theme="day"] .profile-hero{background:var(--panel)}
:root[data-theme="day"] .profile-hero::before{background:radial-gradient(circle,rgba(179,25,66,.06),rgba(19,65,160,.08) 40%,rgba(19,65,160,0) 72%)}
:root[data-theme="day"] .shell-status{border-color:rgba(19,65,160,.16);background:rgba(255,255,255,.95)}
:root[data-theme="day"] .done-chip,:root[data-theme="day"] .st.done,:root[data-theme="day"] .lesson-chip--done,:root[data-theme="day"] .session-grade.ok,:root[data-theme="day"] .session-grade.good{color:var(--day-blue)!important}
:root[data-theme="day"] .brand-mark{background:linear-gradient(180deg,rgba(19,65,160,.08),rgba(19,65,160,.02));color:var(--day-blue)}
.brand-mark svg path[fill="var(--bg)"]{fill:var(--bg)}
.path-feature-card,.app-course-tile,.app-domain-card{overflow:hidden}
.path-feature-art,.app-course-art,.app-domain-art{display:block}

:root[data-theme="day"] .readout .big,:root[data-theme="day"] .readout .val{color:var(--day-blue)}
:root[data-theme="day"] .readout .label{color:var(--day-navy)}


/* ---- pass 14: journey-first courses + premium You ---- */
.course-layout--single{display:flex;flex-direction:column;gap:18px;max-width:980px;margin:0 auto}
.course-layout--single>.chapter-spine{width:100%}
.course-secondary-row{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.course-secondary-row>details{margin:0;min-width:0}
.course-progress-fold>.readout{position:static!important;border:0!important;background:transparent!important;box-shadow:none!important;padding:8px 0 2px!important}
.course-journey-head{display:flex;align-items:flex-end;justify-content:space-between;gap:14px;margin:12px 0 4px;padding:0 2px}
.course-journey-head h2{font-size:31px;line-height:1.05;letter-spacing:-.035em;margin:4px 0 0}
.course-journey-next{display:inline-flex;align-items:center;justify-content:center;min-height:42px;padding:0 14px;border-radius:999px;border:1px solid var(--line);background:var(--panel);font:750 12px/1 var(--sans);color:var(--text);text-decoration:none}
.course-journey-next:hover{text-decoration:none;border-color:var(--line-lift)}
.chapter-spine{gap:10px}
.chapter-card{transition:transform .16s ease,border-color .16s ease,background .16s ease,box-shadow .16s ease}
.chapter-card--next,.chapter-card--progress{box-shadow:0 18px 44px rgba(0,0,0,.14)}
.chapter-card--next{transform:scale(1.012)}
.course-action-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;max-width:980px;margin:18px auto 0}
.course-action-card{display:grid;grid-template-columns:54px 1fr;gap:13px;align-items:center;min-height:92px;padding:16px;border:1px solid var(--line);border-radius:23px;background:var(--panel);color:var(--text);text-decoration:none;box-shadow:0 14px 34px rgba(0,0,0,.12)}
.course-action-card:hover{text-decoration:none;border-color:var(--line-lift);transform:translateY(-1px)}
.course-action-icon{display:grid;place-items:center;width:52px;height:52px;border-radius:17px;background:var(--field);font:800 20px/1 var(--display);color:var(--volt)}
.course-action-card strong{display:block;font:800 17px/1.1 var(--display);letter-spacing:-.02em}.course-action-card span:not(.course-action-icon){display:block;margin-top:5px;font:600 12px/1.35 var(--sans);color:var(--muted)}
.course-action-card--locked{opacity:.58}

.you-hero{overflow:hidden;border:1px solid var(--line);border-radius:32px;background:var(--panel);padding:26px;box-shadow:0 22px 58px rgba(0,0,0,.18);margin-bottom:16px}
.you-hero-main{display:flex;align-items:center;gap:24px}
.you-level-ring{width:150px;height:150px;flex:0 0 150px;border-radius:50%;padding:12px;background:conic-gradient(var(--volt) var(--level-pct),var(--line) 0deg);box-shadow:0 16px 36px rgba(0,0,0,.14)}
.you-level-core{width:100%;height:100%;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--panel);border:8px solid var(--bg)}
.you-level-core span{font:750 10px/1 var(--sans);letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.you-level-core strong{font:850 43px/1 var(--display);letter-spacing:-.04em;margin-top:6px;color:var(--text)}
.you-hero-copy h1{font-size:42px;line-height:1.02;letter-spacing:-.045em;margin:8px 0 8px}.you-hero-copy p{font:600 14px/1.45 var(--sans);color:var(--muted);margin:0}
.you-metric-row{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:9px;margin-top:24px}.you-metric-row .profile-metric{min-width:0}
.you-shortcuts{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px;margin-top:10px}
.you-shortcuts>a{position:relative;display:block;padding:15px 42px 15px 15px;border:1px solid var(--line);border-radius:18px;background:var(--field);color:var(--text);text-decoration:none}.you-shortcuts>a:hover{text-decoration:none;border-color:var(--line-lift)}
.you-shortcuts strong{display:block;font:800 14px/1.1 var(--display)}.you-shortcuts span{display:block;margin-top:5px;font:600 11px/1.2 var(--sans);color:var(--muted)}.you-shortcuts b{position:absolute;right:15px;top:50%;transform:translateY(-50%);font:500 25px/1 var(--sans);color:var(--muted)}
:root[data-theme="day"] .you-level-ring{background:conic-gradient(var(--day-blue) var(--level-pct),var(--level-ring-rest) 0deg);box-shadow:0 14px 34px rgba(10,49,97,.10)}
:root[data-theme="day"] .you-hero,:root[data-theme="day"] .course-action-card,:root[data-theme="day"] .chapter-card--next,:root[data-theme="day"] .chapter-card--progress{box-shadow:0 14px 34px rgba(10,49,97,.07)}
:root[data-theme="day"] .course-action-icon{color:var(--day-blue)}

@media(max-width:760px){
  .course-secondary-row{grid-template-columns:1fr}
  .course-journey-head{align-items:center}.course-journey-head h2{font-size:27px}.course-journey-next{min-height:36px;font-size:11px}
  .chapter-card--done,.chapter-card--locked{grid-template-columns:44px minmax(0,1fr);padding:12px 13px;border-radius:19px;box-shadow:none}
  .chapter-card--done .chapter-body>.progressbar,.chapter-card--done .meta-row,.chapter-card--done .chapter-actions,.chapter-card--done .chapter-top p,
  .chapter-card--locked .chapter-body>.progressbar,.chapter-card--locked .meta-row,.chapter-card--locked .chapter-actions,.chapter-card--locked .chapter-top p{display:none}
  .chapter-card--done .chapter-top,.chapter-card--locked .chapter-top{align-items:center}.chapter-card--done .chapter-top h3,.chapter-card--locked .chapter-top h3{font-size:16px;margin:0}.chapter-card--done .chapter-index,.chapter-card--locked .chapter-index{width:34px;height:34px;font-size:14px}
  .chapter-card--next,.chapter-card--progress,.chapter-card--available{padding:17px 15px;border-radius:23px}.chapter-card--next{transform:none}
  .course-action-grid{grid-template-columns:1fr;gap:9px;margin-top:14px}.course-action-card{min-height:78px;border-radius:20px}.course-action-icon{width:46px;height:46px;border-radius:15px}
  .you-hero{padding:20px 16px;border-radius:28px}.you-hero-main{gap:16px}.you-level-ring{width:104px;height:104px;flex-basis:104px;padding:8px}.you-level-core{border-width:6px}.you-level-core strong{font-size:30px}.you-hero-copy h1{font-size:30px;margin:6px 0}.you-hero-copy p{font-size:12px}
  .you-metric-row{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin-top:18px}.you-shortcuts{grid-template-columns:1fr}.you-shortcuts>a{min-height:64px}
}


/* ---- pass 15: snappy navigation + graphical questions ---- */
body.app-shell::after{content:'';position:fixed;z-index:500;left:0;top:0;width:0;height:3px;background:var(--volt);opacity:0;pointer-events:none;box-shadow:0 0 18px color-mix(in srgb,var(--volt) 45%,transparent)}
body.shell-navigating::after{width:74%;opacity:1;transition:width .18s cubic-bezier(.2,.8,.2,1),opacity .08s}
body.shell-leaving::after{width:100%;opacity:1;transition:width .09s linear}
:root[data-theme="day"] body.app-shell::after{background:var(--day-blue);box-shadow:0 0 14px rgba(19,65,160,.24)}
.app-course-tile,.app-domain-card,.path-feature-card,.fasttracks-card,.fasttrack-station,.chapter-card,.app-quick-card,.personal-link-card,.bb-item{touch-action:manipulation}
.q.q-visual{padding:0;overflow:hidden}
.q-visual-stage{min-height:210px;display:grid;place-items:center;background:var(--board);border-bottom:1px solid var(--line);padding:12px}
.q-visual-stage svg{display:block;width:100%;height:auto;max-height:230px}
.q.q-visual>.prompt{padding:20px 20px 0;margin:0;font:750 21px/1.3 var(--display);letter-spacing:-.02em}
.q.q-visual>.conf{margin:14px 20px 0}
.q.q-visual>div:not(.q-visual-stage):not(.conf):not(.fb){margin-left:20px;margin-right:20px}
.q.q-visual>.fb{margin:16px 20px 20px}
.q.q-visual .opts{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:14px}
.q.q-visual .opts button{min-height:72px;border-radius:18px;padding:13px 15px;font:700 14px/1.3 var(--sans);text-align:left;background:var(--panel)}
.q.q-visual .opts button.sel{background:color-mix(in srgb,var(--volt) 7%,var(--panel));box-shadow:inset 0 0 0 2px var(--volt)}
.q-visual-tag{display:inline-flex;align-items:center;min-height:28px;padding:0 10px;border-radius:999px;font:750 10px/1 var(--sans);letter-spacing:.08em;text-transform:uppercase;background:var(--panel);border:1px solid var(--line);color:var(--muted)}
@media(max-width:720px){
  .q-visual-stage{min-height:180px;padding:8px}
  .q.q-visual>.prompt{font-size:20px;padding:18px 17px 0}
  .q.q-visual>.conf{margin-left:17px;margin-right:17px}
  .q.q-visual>div:not(.q-visual-stage):not(.conf):not(.fb){margin-left:17px;margin-right:17px}
  .q.q-visual .opts{grid-template-columns:1fr}
  .q.q-visual .opts button{min-height:64px}
}

/* ---- pass 15b: instant lesson opening ---- */
.lesson-loading-screen{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(260px,.85fr);gap:16px;align-items:stretch}
.lesson-loading-art{min-height:300px;border-radius:30px;overflow:hidden;border:1px solid var(--line)}
.lesson-loading-card{align-self:stretch;justify-content:center;min-height:180px}
@media(max-width:720px){
  .lesson-loading-screen{grid-template-columns:1fr;gap:12px}
  .lesson-loading-art{min-height:210px;border-radius:24px}
  .lesson-loading-card{min-height:104px}
}

/* ---- pass 16: manipulate the engineering object ---- */
.q.q-interactive{padding:0;overflow:hidden}
.q-play{border-bottom:1px solid var(--line);background:var(--board)}
.q-play-head{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:14px 18px 8px}
.q-play-kicker{font:800 10px/1 var(--sans);letter-spacing:.12em;text-transform:uppercase;color:var(--volt)}
.q-play-hint{font:600 12px/1.35 var(--sans);color:var(--muted);text-align:right;max-width:58ch}
.q-play-stage{min-height:220px;display:grid;place-items:center;padding:0 10px 4px}
.q-play-stage svg{display:block;width:100%;height:auto;max-height:270px}
.q-play-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;padding:10px 18px 18px}
.q-play-range{display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:10px;min-height:52px;padding:10px 12px;border:1px solid var(--line);border-radius:16px;background:var(--panel)}
.q-play-range>span{font:700 11px/1 var(--sans);color:var(--muted);white-space:nowrap}
.q-play-range input{margin:0;min-width:80px}
.q-play-value{font:800 12px/1 var(--sans);color:var(--text);min-width:52px;text-align:right;font-variant-numeric:tabular-nums}
.q-play-choice{min-height:52px;border-radius:16px!important;border:1px solid var(--line)!important;background:var(--panel)!important;color:var(--text)!important;font:750 12px/1.2 var(--sans)!important;padding:10px 14px!important}
.q-play-choice.on{border-color:var(--volt)!important;box-shadow:inset 0 0 0 2px var(--volt);background:color-mix(in srgb,var(--volt) 6%,var(--panel))!important}
.q.q-interactive>.prompt{padding:20px 20px 0;margin:0;font:760 21px/1.3 var(--display);letter-spacing:-.02em}
.q.q-interactive>.conf{margin:14px 20px 0}
.q.q-interactive>div:not(.q-play):not(.conf):not(.fb){margin-left:20px;margin-right:20px}
.q.q-interactive>.fb{margin:16px 20px 20px}
.q.q-interactive .opts{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:14px}
.q.q-interactive .opts button{min-height:64px;border-radius:18px;padding:13px 15px;font:700 14px/1.3 var(--sans);text-align:left;background:var(--panel)}
.q.q-interactive .opts button.sel{background:color-mix(in srgb,var(--volt) 7%,var(--panel));box-shadow:inset 0 0 0 2px var(--volt)}
:root[data-theme="day"] .q-play-kicker{color:var(--day-blue)}
:root[data-theme="day"] .q-play-choice.on{border-color:var(--day-blue)!important;box-shadow:inset 0 0 0 2px var(--day-blue);background:rgba(19,65,160,.045)!important}

@media(max-width:720px){
  .q-play-head{align-items:flex-start;flex-direction:column;padding:13px 15px 6px;gap:6px}
  .q-play-hint{text-align:left;font-size:11px}
  .q-play-stage{min-height:190px;padding:0 4px}
  .q-play-controls{grid-template-columns:1fr;padding:8px 14px 14px;gap:8px}
  .q-play-range{grid-template-columns:88px minmax(0,1fr) 58px;gap:8px;border-radius:15px}
  .q.q-interactive>.prompt{font-size:19px;padding:17px 16px 0}
  .q.q-interactive>.conf{margin-left:16px;margin-right:16px}
  .q.q-interactive>div:not(.q-play):not(.conf):not(.fb){margin-left:16px;margin-right:16px}
  .q.q-interactive .opts{grid-template-columns:1fr}
  .q.q-interactive .opts button{min-height:60px}
}
.q-play-stage--arm svg,.q-play-stage--poles svg{touch-action:none;cursor:grab}
.q-play-stage--arm svg:active,.q-play-stage--poles svg:active{cursor:grabbing}
.q .conf-after-answer{margin-top:16px!important;padding-top:14px;border-top:1px solid var(--line)}
.q-submit-row{margin-top:10px!important;padding-bottom:2px}
.q-submit-row .primary{width:100%;min-height:52px;border-radius:16px;font:800 14px/1 var(--sans)}
.q.q-interactive>.conf-after-answer,.q.q-visual>.conf-after-answer{margin-left:20px;margin-right:20px}
@media(max-width:720px){
  .q.q-interactive>.conf-after-answer,.q.q-visual>.conf-after-answer{margin-left:16px;margin-right:16px}
}


/* ---- pass 17: answer on the engineering object ---- */
.q.q-interactive>.prompt{padding:22px 20px 16px;margin:0;font:800 23px/1.25 var(--display);letter-spacing:-.025em}
.q.q-interactive>.q-play{border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.q-direct-selection{display:flex;align-items:center;min-height:48px;margin-top:14px!important;padding:11px 14px;border:1px solid color-mix(in srgb,var(--volt) 24%,var(--line));border-radius:15px;background:color-mix(in srgb,var(--volt) 4%,var(--panel));font:750 13px/1.3 var(--sans);color:var(--text)}
.q-answer-fallback{margin-top:10px;border:1px solid var(--line);border-radius:15px;background:var(--field);overflow:hidden}
.q-answer-fallback>summary{min-height:42px;display:flex;align-items:center;padding:0 13px;cursor:pointer;list-style:none;font:700 12px/1 var(--sans);color:var(--muted)}
.q-answer-fallback>summary::-webkit-details-marker{display:none}
.q-answer-fallback>summary::after{content:'›';margin-left:auto;font-size:19px;transform:rotate(90deg);transition:transform .15s ease}
.q-answer-fallback[open]>summary::after{transform:rotate(-90deg)}
.q-answer-fallback .opts,.q-answer-fallback .numrow{margin:0 10px 10px!important}
.q-direct-object .q-play-stage [data-tight],.q-direct-object .q-play-stage [data-wide],.q-direct-object .q-play-stage [data-radial],.q-direct-object .q-play-stage [data-axial]{transition:opacity .14s ease,filter .14s ease}
.q-direct-object .q-play-stage [data-tight]:hover,.q-direct-object .q-play-stage [data-wide]:hover,.q-direct-object .q-play-stage [data-radial]:hover,.q-direct-object .q-play-stage [data-axial]:hover{filter:drop-shadow(0 0 8px color-mix(in srgb,var(--volt) 44%,transparent))}
.q .conf-after-answer[hidden]{display:none!important}
.q .conf-after-answer.ready{animation:qConfidenceIn .14s ease-out both}
@keyframes qConfidenceIn{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:none}}
:root[data-theme="day"] .q-direct-selection{border-color:rgba(19,65,160,.2);background:rgba(19,65,160,.035)}
@media(max-width:720px){
  .q.q-interactive>.prompt{font-size:21px;padding:18px 16px 14px}
  .q-direct-selection{min-height:46px;margin-top:11px!important;border-radius:14px;font-size:12.5px}
  .q-answer-fallback{border-radius:14px}
  .q-play-controls{padding-bottom:12px}
}

.q-play-answer-row{grid-column:1/-1;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px}
.q-play-answer-tile{display:grid;grid-template-columns:42px 1fr;align-items:center;gap:9px;min-height:68px!important;padding:10px 12px!important;border-radius:17px!important;border:1px solid var(--line)!important;background:var(--panel)!important;color:var(--text)!important;text-align:left!important}
.q-play-answer-tile strong{font:800 12px/1.15 var(--sans);color:inherit}
.q-play-answer-glyph{display:grid;place-items:center;width:42px;height:42px;border-radius:13px;background:var(--field);color:var(--volt)}
.q-play-answer-glyph svg{width:30px;height:30px;display:block}
.q-play-answer-tile.on{border-color:var(--volt)!important;box-shadow:inset 0 0 0 2px var(--volt);background:color-mix(in srgb,var(--volt) 5%,var(--panel))!important}
:root[data-theme="day"] .q-play-answer-glyph{color:var(--day-blue)}
:root[data-theme="day"] .q-play-answer-tile.on{border-color:var(--day-blue)!important;box-shadow:inset 0 0 0 2px var(--day-blue);background:rgba(19,65,160,.04)!important}
@media(max-width:720px){
  .q-play-answer-row{grid-template-columns:1fr 1fr 1fr;gap:7px}
  .q-play-answer-tile{grid-template-columns:1fr;justify-items:center;text-align:center!important;min-height:86px!important;padding:9px 7px!important}
  .q-play-answer-tile strong{font-size:11px}
}

/* ---- pass 18: navigation architecture — Courses / Builds / Practice / Tools / You ---- */
.app-courses-home{gap:26px}
.course-category-shell{position:sticky;top:0;z-index:58;margin:0 -16px;padding:8px 16px 10px;background:color-mix(in srgb,var(--bg) 91%,transparent);backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border-bottom:1px solid color-mix(in srgb,var(--line) 68%,transparent)}
.course-category-rail{display:flex;gap:8px;overflow-x:auto;overscroll-behavior-x:contain;scrollbar-width:none;padding:2px 0;scroll-snap-type:x proximity}
.course-category-rail::-webkit-scrollbar{display:none}
.course-category-tab{flex:none;min-height:42px;padding:0 16px;border-radius:999px;border:1px solid var(--line);background:var(--panel);color:var(--muted);font:750 13px/1 var(--sans);white-space:nowrap;scroll-snap-align:start;box-shadow:none}
.course-category-tab:hover{border-color:var(--line-lift);color:var(--text)}
.course-category-tab.on{background:var(--volt);border-color:var(--volt);color:var(--on-volt);box-shadow:0 8px 20px color-mix(in srgb,var(--volt) 16%,transparent)}
:root[data-theme="day"] .course-category-shell{background:color-mix(in srgb,var(--bg) 94%,transparent)}
:root[data-theme="day"] .course-category-tab.on{background:var(--day-blue);border-color:var(--day-blue);color:#fff;box-shadow:0 8px 20px rgba(19,65,160,.14)}

.courses-hero-slot{display:block;transition:opacity .14s ease,max-height .18s ease,margin .18s ease;max-height:640px;overflow:visible}
.courses-hero-slot.is-filtered{max-height:0;opacity:0;overflow:hidden;margin-top:-18px;pointer-events:none}
.course-catalog{scroll-margin-top:70px;display:flex;flex-direction:column;gap:16px}
.course-catalog-head{display:flex;align-items:flex-end;justify-content:space-between;gap:18px}
.course-catalog-head .app-eyebrow{margin:0 0 7px}
.course-catalog-head h1{font-size:34px;line-height:1.03;letter-spacing:-.04em;margin:0;max-width:16ch}
.course-count{flex:none;padding:8px 11px;border:1px solid var(--line);border-radius:999px;background:var(--field);font:750 11px/1 var(--sans);color:var(--muted)}
.course-catalog-search{width:100%;height:52px;padding:0 17px;border:1px solid var(--line);border-radius:17px;background:var(--field);color:var(--text);font:600 15px/1 var(--sans)}
.course-catalog-search::placeholder{color:var(--muted-2)}
.course-catalog-search:focus{outline:none;border-color:var(--volt);box-shadow:0 0 0 3px color-mix(in srgb,var(--volt) 10%,transparent)}
:root[data-theme="day"] .course-catalog-search:focus{border-color:var(--day-blue);box-shadow:0 0 0 3px rgba(19,65,160,.08)}
.course-catalog-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.course-catalog-card{display:grid;grid-template-rows:190px auto;overflow:hidden;border:1px solid var(--line);border-radius:28px;background:var(--panel);color:var(--text);text-decoration:none;box-shadow:0 16px 40px rgba(0,0,0,.12);transition:transform .14s ease,border-color .14s ease,box-shadow .14s ease}
.course-catalog-card:hover{text-decoration:none;transform:translateY(-2px);border-color:var(--line-lift);box-shadow:0 20px 46px rgba(0,0,0,.16)}
.course-catalog-art{border-bottom:1px solid var(--line)}
.course-catalog-card-body{display:flex;flex-direction:column;padding:18px 19px 19px}
.course-catalog-card-meta{display:flex;justify-content:space-between;gap:12px;align-items:center;font:750 10.5px/1 var(--sans);text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.course-catalog-card-meta strong{color:var(--volt)}
:root[data-theme="day"] .course-catalog-card-meta strong{color:var(--day-blue)}
.course-catalog-card h2{font-size:23px;line-height:1.08;letter-spacing:-.03em;margin:10px 0 7px;color:var(--text)}
.course-catalog-card p{font:550 13px/1.45 var(--sans);color:var(--muted);margin:0;min-height:38px}
.course-catalog-progress{height:7px;margin:17px 0 12px}
.course-catalog-next{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:auto;font:700 12px/1.25 var(--sans);color:var(--muted)}
.course-catalog-next span{font-size:24px;line-height:1;color:var(--text)}
:root[data-theme="day"] .course-catalog-card{box-shadow:0 12px 28px rgba(10,49,97,.055)}

.courses-build-promo{display:grid;grid-template-columns:260px minmax(0,1fr);min-height:210px;overflow:hidden;border:1px solid var(--line);border-radius:30px;background:var(--panel);color:var(--text);text-decoration:none;box-shadow:0 16px 40px rgba(0,0,0,.12)}
.courses-build-promo:hover{text-decoration:none;border-color:var(--line-lift)}
.courses-build-promo-art{border-right:1px solid var(--line)}
.courses-build-promo-copy{display:flex;flex-direction:column;justify-content:center;padding:26px 28px}
.courses-build-promo-copy .app-eyebrow{margin:0 0 9px}
.courses-build-promo-copy h2{font-size:28px;letter-spacing:-.035em;margin:0 0 8px}
.courses-build-promo-copy p{font:550 14px/1.5 var(--sans);color:var(--muted);margin:0 0 15px;max-width:48ch}
.courses-build-promo-copy strong{font:800 13px/1 var(--sans);color:var(--volt)}
:root[data-theme="day"] .courses-build-promo-copy strong{color:var(--day-blue)}

/* Practice is a hub. Today is a mode inside it, not a primary app destination. */
.practice-hub{display:flex;flex-direction:column;gap:18px;max-width:860px;margin:0 auto}
.practice-hub-hero{display:grid;grid-template-columns:minmax(0,1fr) 320px;overflow:hidden;border:1px solid var(--line);border-radius:32px;background:var(--panel);box-shadow:0 20px 52px rgba(0,0,0,.16)}
.practice-hub-copy{display:flex;flex-direction:column;justify-content:center;padding:30px}
.practice-hub-copy .app-eyebrow{margin:0 0 10px}
.practice-hub-copy h1{font-size:42px;line-height:1.02;letter-spacing:-.045em;margin:0 0 11px;max-width:11ch}
.practice-hub-copy p{font:560 15px/1.5 var(--sans);color:var(--muted);margin:0;max-width:42ch}
.practice-hub-art{border-left:1px solid var(--line);min-height:250px}
.practice-primary{display:grid;grid-template-columns:64px minmax(0,1fr) 28px;align-items:center;gap:16px;min-height:112px;padding:18px 20px;border:1px solid color-mix(in srgb,var(--volt) 34%,var(--line));border-radius:26px;background:linear-gradient(135deg,color-mix(in srgb,var(--volt) 7%,var(--panel)),var(--panel));color:var(--text);text-decoration:none}
.practice-primary:hover{text-decoration:none;border-color:var(--volt)}
.practice-primary .app-action-icon{width:64px;height:64px}
.practice-primary>div span{display:block;font:700 12px/1 var(--sans);color:var(--muted);margin-bottom:7px}
.practice-primary>div strong{display:block;font:800 23px/1.12 var(--display);letter-spacing:-.025em;color:var(--text)}
.practice-primary-arrow{font-size:30px;color:var(--text)}
.practice-mode-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.practice-mode-card{display:grid;grid-template-columns:54px minmax(0,1fr) 18px;gap:13px;align-items:center;min-height:120px;padding:17px;border:1px solid var(--line);border-radius:23px;background:var(--panel);color:var(--text);text-decoration:none}
.practice-mode-card:hover{text-decoration:none;border-color:var(--line-lift);background:var(--panel-lift)}
.practice-mode-card .app-action-icon{width:54px;height:54px;border-radius:17px}
.practice-mode-top{display:flex;justify-content:space-between;gap:10px;align-items:center}
.practice-mode-top h2{font-size:19px;margin:0;color:var(--text)}
.practice-mode-top span{font:750 10.5px/1 var(--sans);color:var(--volt)}
.practice-mode-copy p{font:550 12.5px/1.4 var(--sans);color:var(--muted);margin:6px 0 0}
.practice-mode-arrow{font-size:24px;color:var(--muted)}
.practice-continue{display:flex;justify-content:space-between;gap:16px;align-items:center;padding:17px 19px;border:1px solid var(--line);border-radius:20px;background:var(--field);color:var(--text);text-decoration:none}
.practice-continue:hover{text-decoration:none;border-color:var(--line-lift)}
.practice-continue span{display:block;font:700 11px/1 var(--sans);color:var(--muted);margin-bottom:6px}.practice-continue strong{font:750 16px/1.2 var(--display);color:var(--text)}
:root[data-theme="day"] .practice-hub-hero,:root[data-theme="day"] .practice-mode-card,:root[data-theme="day"] .practice-primary{box-shadow:0 12px 28px rgba(10,49,97,.05)}
:root[data-theme="day"] .practice-mode-top span{color:var(--day-blue)}

@media(max-width:720px){
  .course-category-shell{margin:0 -14px;padding:7px 14px 9px;top:0}
  .course-category-tab{min-height:39px;padding:0 14px;font-size:12.5px}
  .app-courses-home{gap:22px}
  .course-catalog-head{align-items:flex-end}
  .course-catalog-head h1{font-size:29px;max-width:13ch}
  .course-catalog-grid{grid-template-columns:1fr;gap:12px}
  .course-catalog-card{grid-template-columns:126px minmax(0,1fr);grid-template-rows:auto;min-height:155px;border-radius:23px}
  .course-catalog-art{height:100%;min-height:155px;border-right:1px solid var(--line);border-bottom:0}
  .course-catalog-card-body{padding:15px 15px 14px}
  .course-catalog-card h2{font-size:19px;margin:8px 0 5px}
  .course-catalog-card p{display:none}
  .course-catalog-progress{margin:13px 0 9px}
  .course-catalog-next{font-size:11.5px}
  .courses-build-promo{grid-template-columns:126px minmax(0,1fr);min-height:170px;border-radius:24px}
  .courses-build-promo-art{height:100%;border-right:1px solid var(--line)}
  .courses-build-promo-copy{padding:18px 16px}
  .courses-build-promo-copy h2{font-size:21px;margin-bottom:7px}
  .courses-build-promo-copy p{font-size:12.5px;line-height:1.4;margin-bottom:12px}
  .courses-build-promo-copy strong{font-size:12px}
  .practice-hub{gap:14px}
  .practice-hub-hero{grid-template-columns:1fr;border-radius:27px}
  .practice-hub-copy{padding:23px 19px 20px}
  .practice-hub-copy h1{font-size:34px;max-width:13ch}
  .practice-hub-copy p{font-size:14px}
  .practice-hub-art{height:170px;min-height:170px;border-left:0;border-top:1px solid var(--line)}
  .practice-primary{grid-template-columns:58px minmax(0,1fr) 20px;min-height:100px;padding:15px;border-radius:22px}
  .practice-primary .app-action-icon{width:58px;height:58px;border-radius:18px}
  .practice-primary>div strong{font-size:20px}
  .practice-mode-grid{grid-template-columns:1fr;gap:10px}
  .practice-mode-card{min-height:94px;padding:14px;border-radius:20px}
}
.tool-destination-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:16px 0 18px}
.tool-destination-card{display:flex;align-items:center;justify-content:space-between;gap:12px;min-height:86px;padding:15px 16px;border:1px solid var(--line);border-radius:20px;background:var(--panel);color:var(--text);text-decoration:none}
.tool-destination-card:hover{text-decoration:none;border-color:var(--line-lift);background:var(--panel-lift)}
.tool-destination-card strong{display:block;font:760 15px/1.15 var(--display);color:var(--text)}
.tool-destination-card span{display:block;margin-top:5px;font:550 11.5px/1.35 var(--sans);color:var(--muted)}
.tool-destination-card b{font-size:22px;color:var(--muted)}
@media(max-width:720px){.tool-destination-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}.tool-destination-card{min-height:92px;padding:14px;border-radius:18px}}

/* ---- pass 19: flagship Courses experience ---- */
.app-courses-home{gap:24px}
.app-resume-promise{margin:8px 0 0;font:650 14px/1.45 var(--sans);color:var(--muted);max-width:48ch}
.course-search-shell{position:relative;display:block}
.course-search-glyph{position:absolute;left:16px;top:50%;transform:translateY(-51%);z-index:1;color:var(--muted);font:800 22px/1 var(--sans);pointer-events:none}
.course-search-shell .course-catalog-search{padding-left:46px}
.course-catalog-zone{min-width:0}
.course-discipline-stack{display:flex;flex-direction:column;gap:28px;min-width:0}
.course-discipline{min-width:0}
.course-discipline-head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin:0 0 12px}
.course-discipline-head h2{margin:0;font:800 26px/1 var(--display);letter-spacing:-.035em;color:var(--text)}
.course-discipline-head span{display:block;margin-top:5px;font:650 11px/1 var(--sans);color:var(--muted)}
.course-discipline-see{min-height:36px;padding:0 12px;border-radius:999px;border:1px solid var(--line);background:var(--field);color:var(--text);font:750 12px/1 var(--sans);box-shadow:none}
.course-discipline-see:hover{border-color:var(--line-lift);background:var(--panel-lift)}
.course-discipline-rail{display:flex;gap:13px;overflow-x:auto;overscroll-behavior-x:contain;scrollbar-width:none;scroll-snap-type:x mandatory;padding:1px 1px 7px}
.course-discipline-rail::-webkit-scrollbar{display:none}
.course-catalog-card--rail{flex:0 0 min(350px,78vw);width:min(350px,78vw);scroll-snap-align:start;grid-template-rows:174px auto;box-shadow:0 13px 34px rgba(0,0,0,.11)}
.course-card-tags{display:flex;gap:6px;flex-wrap:wrap;margin:11px 0 0}
.course-card-tags span{display:inline-flex;align-items:center;min-height:26px;padding:0 8px;border:1px solid var(--line);border-radius:999px;background:var(--field);font:700 10px/1 var(--sans);color:var(--muted);white-space:nowrap}
.course-card-promise{min-height:0!important}
:root[data-theme="day"] .course-discipline-see{background:#fff}
:root[data-theme="day"] .course-card-tags span{background:var(--field)}

/* Course pages: identity first, one enormous next action, telemetry second. */
.course-hero--identity .course-hero-main{display:flex;flex-direction:column;justify-content:center}
.course-identity-promise{margin:8px 0 0;max-width:44ch;font:650 17px/1.45 var(--sans);color:var(--muted)}
.course-identity-tags{display:flex;gap:8px;flex-wrap:wrap;margin:18px 0 0}
.course-identity-tags span{display:inline-flex;align-items:center;min-height:31px;padding:0 10px;border:1px solid var(--line);border-radius:999px;background:var(--field);font:750 11px/1 var(--sans);color:var(--muted)}
.course-hero-progress{margin:22px 0 10px!important}
.course-hero-meta{margin:0}
.course-next-card{display:grid;grid-template-columns:minmax(300px,.9fr) minmax(0,1.1fr);overflow:hidden;margin:16px 0 22px;border:1px solid color-mix(in srgb,var(--volt) 28%,var(--line));border-radius:32px;background:var(--panel);box-shadow:0 20px 52px rgba(0,0,0,.16)}
.course-next-art{min-height:300px;border-right:1px solid var(--line)}
.course-next-copy{display:flex;flex-direction:column;justify-content:center;padding:30px 32px}
.course-next-copy .app-eyebrow{margin:0 0 10px}
.course-next-id{font:750 11px/1.2 var(--mono);color:var(--muted);text-transform:uppercase;letter-spacing:.06em}
.course-next-copy h2{margin:8px 0 9px;font:800 clamp(29px,4vw,44px)/1.02 var(--display);letter-spacing:-.045em;color:var(--text);max-width:14ch}
.course-next-copy p{margin:0;font:560 14px/1.48 var(--sans);color:var(--muted);max-width:48ch}
.course-next-button{align-self:flex-start;min-width:180px;margin-top:22px;text-align:center}
.course-next-card--complete{border-color:var(--line)}
:root[data-theme="day"] .course-next-card{border-color:rgba(19,65,160,.18);box-shadow:0 15px 36px rgba(10,49,97,.07)}

/* Finished/locked chapters become context, not competing calls to action. */
.chapter-card--done,.chapter-card--locked{box-shadow:none}
.chapter-card--done .chapter-top p,.chapter-card--locked .chapter-top p{display:none}
.chapter-card--done .chapter-actions,.chapter-card--locked .chapter-actions{display:none}
.chapter-card--done{opacity:.82}
.chapter-card--locked{opacity:.62}
.course-journey-next--label{pointer-events:none;color:var(--muted)!important;border-color:var(--line)!important;background:var(--field)!important}

@media(max-width:720px){
  .course-category-shell{padding-top:5px;padding-bottom:8px}
  .course-category-rail{gap:7px;scroll-snap-type:x mandatory}
  .course-category-tab{min-height:38px;padding:0 13px}
  .courses-hero-slot{transition:opacity .10s ease,max-height .13s ease,margin .13s ease}
  .app-resume-promise{font-size:13px;margin-top:6px}
  .course-catalog{gap:13px}
  .course-catalog-head h1{font-size:27px}
  .course-search-shell .course-catalog-search{height:48px;border-radius:16px}
  .course-discipline-stack{gap:25px}
  .course-discipline-head{margin-bottom:10px}
  .course-discipline-head h2{font-size:23px}
  .course-discipline-rail{margin-right:-14px;padding-right:14px;gap:11px}
  .course-catalog-card--rail{flex-basis:82vw;width:82vw;grid-template-columns:1fr;grid-template-rows:172px auto;min-height:0;border-radius:25px}
  .course-catalog-card--rail .course-catalog-art{height:172px;min-height:172px;border-right:0;border-bottom:1px solid var(--line)}
  .course-catalog-card--rail .course-catalog-card-body{padding:16px 17px 17px}
  .course-catalog-card--rail h2{font-size:22px;margin:9px 0 6px}
  .course-catalog-card--rail .course-card-promise{display:block;font-size:12.5px;line-height:1.4}
  .course-catalog-card--rail .course-card-tags{display:flex}
  .course-catalog-grid{grid-template-columns:1fr;gap:12px}
  .course-catalog-grid .course-catalog-card{grid-template-columns:1fr;grid-template-rows:174px auto;min-height:0;border-radius:25px}
  .course-catalog-grid .course-catalog-art{height:174px;min-height:174px;border-right:0;border-bottom:1px solid var(--line)}
  .course-catalog-grid .course-catalog-card-body{padding:16px 17px 17px}
  .course-catalog-grid .course-catalog-card h2{font-size:22px;margin:9px 0 6px}
  .course-catalog-grid .course-card-promise{display:block;font-size:12.5px;line-height:1.4}
  .course-catalog-grid .course-card-tags{display:flex}
  .course-catalog-progress{margin:13px 0 10px}

  .course-hero--identity{border-radius:27px}
  .course-hero--identity .course-hero-art{height:205px;min-height:205px}
  .course-identity-promise{font-size:14px;line-height:1.42}
  .course-identity-tags{margin-top:13px;gap:6px}
  .course-identity-tags span{min-height:28px;font-size:10px}
  .course-hero-progress{margin-top:16px!important}
  .course-next-card{grid-template-columns:1fr;margin:13px 0 20px;border-radius:27px}
  .course-next-art{height:210px;min-height:210px;border-right:0;border-bottom:1px solid var(--line)}
  .course-next-copy{padding:21px 19px 20px}
  .course-next-copy h2{font-size:31px;max-width:15ch;margin-top:7px}
  .course-next-copy p{font-size:13px}
  .course-next-button{width:100%;margin-top:18px;min-height:52px}
  .chapter-card--done,.chapter-card--locked{min-height:0}
}

/* ---- pass 20: editorial Bauhaus / constructivist art system ---- */
/* One visual factory: paper, heavy structure, small saturated accents. */
.app-art{
  --art-paper:var(--editorial-paper);
  --art-ink:var(--editorial-ink);
  --art-muted:var(--editorial-muted);
  --art-accent:var(--editorial-blue);
  --art-hot:var(--editorial-red);
  --art-secondary:var(--editorial-yellow);
  color:var(--art-ink);
  background:var(--editorial-paper);
}
.app-art--robotics{--art-accent:var(--editorial-blue);--art-hot:var(--editorial-red);--art-secondary:var(--editorial-yellow)}
.app-art--electronics{--art-accent:var(--editorial-teal);--art-hot:var(--editorial-red);--art-secondary:var(--editorial-blue)}
.app-art--mechanical{--art-accent:var(--editorial-yellow);--art-hot:var(--editorial-blue);--art-secondary:var(--editorial-red)}
.app-art--manufacturing{--art-accent:var(--editorial-red);--art-hot:var(--editorial-yellow);--art-secondary:var(--editorial-blue)}
.app-art--ai{--art-accent:var(--editorial-violet);--art-hot:var(--editorial-teal);--art-secondary:var(--editorial-blue)}
.app-art--business{--art-accent:var(--editorial-teal);--art-hot:var(--editorial-red);--art-secondary:var(--editorial-yellow)}
.app-art--reference{--art-accent:var(--editorial-blue);--art-hot:var(--editorial-violet);--art-secondary:var(--editorial-yellow)}
.editorial-svg{display:block;width:100%;height:100%;overflow:visible;background:var(--editorial-paper)}
.editorial-svg *{vector-effect:non-scaling-stroke}

/* Art is a piece of editorial paper, not a dark pseudo-render. */
.app-course-art,.app-domain-art,.path-feature-art,.course-hero-art,.course-catalog-art,.app-resume-art,.course-next-art,.courses-build-promo-art,.lesson-hero-art{
  background:var(--editorial-paper)!important;
}
.app-course-art svg,.app-domain-art svg,.path-feature-art svg,.course-hero-art svg,.course-catalog-art svg,.app-resume-art svg,.course-next-art svg,.courses-build-promo-art svg,.lesson-hero-art svg{
  transform:none!important;
  padding:10px 12px;
  box-sizing:border-box;
}
:root[data-theme="day"] .app-art,
:root[data-theme="day"] .app-course-art,
:root[data-theme="day"] .app-domain-art,
:root[data-theme="day"] .path-feature-art,
:root[data-theme="day"] .course-hero-art,
:root[data-theme="day"] .course-catalog-art,
:root[data-theme="day"] .app-resume-art,
:root[data-theme="day"] .course-next-art,
:root[data-theme="day"] .courses-build-promo-art,
:root[data-theme="day"] .lesson-hero-art{background:var(--editorial-paper)!important}

/* Let the art breathe like a spot illustration instead of filling a banner. */
.course-catalog-art{padding:8px 18px;border-bottom:1px solid var(--line)}
.course-catalog-card--rail{grid-template-rows:190px auto}
.course-catalog-card--rail .course-catalog-art{height:190px}
.path-feature-card{grid-template-rows:205px auto}
.path-feature-art{padding:6px 16px}
.app-resume-art,.course-next-art,.course-hero-art{padding:12px 22px}

/* Stronger editorial cards: quieter chrome, art and typography do the work. */
.course-catalog-card,.path-feature-card,.app-resume-hero,.course-next-card,.courses-build-promo{
  box-shadow:0 10px 28px rgba(0,0,0,.10)!important;
  border-color:color-mix(in srgb,var(--line) 82%,transparent)!important;
}
:root[data-theme="day"] .course-catalog-card,
:root[data-theme="day"] .path-feature-card,
:root[data-theme="day"] .app-resume-hero,
:root[data-theme="day"] .course-next-card,
:root[data-theme="day"] .courses-build-promo{box-shadow:0 9px 24px rgba(10,49,97,.065)!important}
.course-card-tags span{border-radius:4px;text-transform:uppercase;letter-spacing:.05em;background:transparent!important}
.course-discipline-see,.app-section-cta{border-radius:4px}
.course-category-tab{border-radius:4px!important}
.course-category-tab.on{box-shadow:none!important}

/* Brand lockup follows one vertical unit: mark top to tagline baseline. */
.brand-mark{
  --brand-ink:var(--brand-editorial-paper);
  --brand-paper:var(--editorial-paper);
  --brand-beam:var(--editorial-volt);
  width:58px!important;height:58px!important;flex:0 0 58px;
  border:0!important;border-radius:0!important;
  background:transparent!important;box-shadow:none!important;
  color:inherit!important;
}
.brand-mark svg{width:58px!important;height:58px!important;display:block}
.brand-lockup{gap:17px!important;align-items:center}
.brand-type{min-height:58px;justify-content:space-between;gap:0!important;padding:2px 0 3px}
header.learn .brand-type a{font-size:23px!important;line-height:1.02!important;letter-spacing:-.035em;font-weight:800!important}
.mark-sub{font-size:10.5px!important;line-height:1!important;letter-spacing:.19em!important;font-weight:750;color:var(--muted)!important}
header.learn{padding-top:10px;padding-bottom:13px}

/* In dark mode the mark stays a crisp black/white editorial object. */
.brand-mark{--brand-ink:var(--brand-editorial-ink);--brand-paper:var(--brand-editorial-paper);--brand-beam:var(--editorial-volt)}

@media(max-width:720px){
  /* Keep the mobile size the user already liked. */
  .brand-mark{width:36px!important;height:36px!important;flex-basis:36px!important}
  .brand-mark svg{width:36px!important;height:36px!important}
  .brand-lockup{gap:9px!important}
  .brand-type{min-height:0;padding:0}
  header.learn .brand-type a{font-size:16px!important}
  .course-catalog-card--rail{grid-template-rows:184px auto}
  .course-catalog-card--rail .course-catalog-art{height:184px;min-height:184px}
  .course-catalog-grid .course-catalog-card{grid-template-rows:184px auto}
  .course-catalog-grid .course-catalog-art{height:184px;min-height:184px}
  .path-feature-card{grid-template-rows:188px auto}
  .path-feature-art{padding:4px 10px}
}
.fasttracks-card-art,.fasttrack-hero-art{background:var(--editorial-paper)!important}
.fasttracks-card-art svg,.fasttrack-hero-art svg{padding:8px 14px;box-sizing:border-box;transform:none!important}

/* Pass 29 — 507 Mechanical Movements showcase animations */
.mech-showcase{margin:14px 0 4px;border:1px solid var(--line);border-radius:26px;overflow:hidden;background:var(--editorial-paper,#fbfbf6);box-shadow:0 18px 46px rgba(0,0,0,.12)}
.mech-showcase-svg{display:block;width:100%;height:auto;aspect-ratio:740/420;background:var(--editorial-paper,#fbfbf6)}
.mech-showcase-controls{display:grid;grid-template-columns:auto auto minmax(140px,1fr) 52px;gap:9px;align-items:center;padding:10px 12px 12px;border-top:1px solid color-mix(in srgb,var(--line) 78%,transparent);background:color-mix(in srgb,var(--panel) 94%,var(--editorial-paper,#fbfbf6))}
.mech-showcase-controls button,.mech-showcase-controls select{min-height:38px;padding:7px 11px;border-radius:11px}
.mech-showcase-controls input[type="range"]{width:100%;accent-color:var(--volt)}
.mech-showcase-phase{text-align:right;font-size:11px}
.mech-showcase-badge{display:inline-flex;align-items:center;gap:7px;padding:6px 9px;border:1px solid var(--line);border-radius:999px;font-size:11px;color:var(--muted);background:var(--panel)}
@media(max-width:720px){.mech-showcase{border-radius:20px}.mech-showcase-controls{grid-template-columns:auto auto 1fr}.mech-showcase-phase{display:none}.mech-showcase-svg{min-height:248px}}

/* 507 Mechanical Movements · Motion Lab */
.mech-motion-lab{max-width:1180px;margin:0 auto;padding:42px 24px 100px}
.mech-motion-hero{max-width:760px;margin-bottom:28px}
.mech-motion-hero h1{font-size:clamp(42px,7vw,78px);line-height:.94;margin:8px 0 14px;letter-spacing:-.055em}
.mech-motion-hero .lede{font-size:18px;line-height:1.55;color:var(--muted);max-width:700px}
.mech-motion-selector{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;margin:28px 0 18px}
.mech-motion-choice{appearance:none;border:1px solid var(--line);background:var(--panel);color:var(--text);min-height:68px;padding:12px 14px;text-align:left;display:flex;gap:12px;align-items:center;cursor:pointer;border-radius:10px;font:inherit}
.mech-motion-choice .mono{font-size:11px;color:var(--muted);letter-spacing:.08em}
.mech-motion-choice.on{border-color:var(--editorial-blue);box-shadow:inset 0 -3px 0 var(--editorial-blue)}
.mech-motion-stage{border-top:1px solid var(--line);padding-top:22px}
.mech-motion-stage-head{display:grid;grid-template-columns:minmax(0,1fr) minmax(260px,.7fr);gap:20px;align-items:end;margin-bottom:14px}
.mech-motion-stage-head h2{font-size:clamp(28px,4vw,46px);line-height:1;margin:5px 0 0;letter-spacing:-.035em}
.mech-motion-stage>.mech-showcase{margin-top:10px}
@media(max-width:800px){.mech-motion-lab{padding:24px 14px 84px}.mech-motion-selector{grid-template-columns:repeat(2,minmax(0,1fr))}.mech-motion-stage-head{grid-template-columns:1fr}.mech-motion-choice{min-height:58px;padding:10px}}

/* Pass 33 — experiment-first lesson interaction */
.lesson-experiment-first{margin:14px 0 16px;padding:12px;border:1px solid var(--line);border-radius:20px;background:color-mix(in srgb,var(--panel) 88%,var(--volt) 4%);box-shadow:0 12px 32px rgba(0,0,0,.07)}
.lesson-experiment-eyebrow{display:inline-flex;align-items:center;min-height:27px;padding:4px 9px;border-radius:999px;background:var(--ink);color:var(--bg);font-size:11px;font-weight:850;letter-spacing:.09em;text-transform:uppercase}
.lesson-experiment-prompt{margin:9px 2px 10px;font-size:14px;line-height:1.45;color:var(--muted);max-width:68ch}
.lesson-experiment-first .lesson-concept-sim{margin:10px 0 0}
.lesson-explain-cue{display:flex;align-items:center;gap:10px;margin:17px 0 7px;font-size:11px;font-weight:850;letter-spacing:.09em;text-transform:uppercase;color:var(--muted)}
.lesson-explain-cue:after{content:"";height:1px;flex:1;background:var(--line)}
@media(max-width:720px){.lesson-experiment-first{margin-inline:-4px;padding:10px;border-radius:17px}.lesson-experiment-prompt{font-size:13px}}
.mech-showcase-argument{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:1px;border-top:1px solid var(--line);background:var(--line)}
.mech-showcase-argument-cell{min-width:0;padding:10px 12px;background:var(--panel)}
.mech-showcase-argument-cell span{display:block;margin-bottom:3px;font-size:9px;font-weight:900;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.mech-showcase-argument-cell strong{display:block;font-size:11px;line-height:1.3;color:var(--ink)}
@media(max-width:720px){.mech-showcase-argument{grid-template-columns:1fr 1fr}.mech-showcase-argument-cell{padding:8px 9px}}

/* Pass 34 — exhibit-first lesson interactions */
.lesson-watch-row{display:flex;gap:8px;flex-wrap:wrap;margin:10px 0 14px}
.lesson-watch-chip{min-height:34px;padding:0 11px;border:1px solid var(--line);border-radius:999px;background:transparent;color:var(--muted);font:750 11px/1 var(--sans);text-transform:uppercase;letter-spacing:.055em;box-shadow:none}
.lesson-watch-chip.on{border-color:var(--volt);background:color-mix(in srgb,var(--volt) 13%,transparent);color:var(--text)}
.lesson-explain-cue{display:flex!important;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap}
.lesson-explain-rule{font:650 11px/1.35 var(--sans);color:var(--muted);text-transform:none;letter-spacing:0}
.concept-motion{margin:10px 0 0;border:1px solid var(--line);border-radius:24px;overflow:hidden;background:var(--panel);box-shadow:0 16px 38px rgba(0,0,0,.12)}
.concept-motion-head{display:flex;align-items:flex-start;justify-content:space-between;gap:18px;padding:16px 17px 13px;border-bottom:1px solid var(--line)}
.concept-motion-head>div{display:flex;flex-direction:column;gap:4px}
.concept-motion-kicker{font:800 10px/1 var(--mono);text-transform:uppercase;letter-spacing:.09em;color:var(--volt)}
.concept-motion-head strong{font:800 18px/1.1 var(--display);letter-spacing:-.025em;color:var(--text)}
.concept-motion-head p{max-width:44ch;margin:0;font:560 12px/1.45 var(--sans);color:var(--muted)}
.concept-motion-stage{background:var(--field)}
.concept-motion-stage svg{display:block;width:100%;height:auto;aspect-ratio:640/330}
.concept-motion-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;padding:13px 14px 15px;border-top:1px solid var(--line)}
.concept-motion-range{display:grid;grid-template-columns:auto minmax(80px,1fr) auto;gap:10px;align-items:center;min-width:0;padding:9px 10px;border:1px solid var(--line);border-radius:14px;background:var(--field)}
.concept-motion-range span{font:700 11px/1.2 var(--sans);color:var(--muted)}
.concept-motion-range input{min-width:0;width:100%;accent-color:var(--volt)}
.concept-motion-range strong{min-width:46px;text-align:right;font:800 11px/1 var(--mono);color:var(--text)}
@media(max-width:720px){
  .lesson-watch-row{display:grid;grid-template-columns:repeat(3,1fr);gap:6px}
  .lesson-watch-chip{padding:0 5px;font-size:9.5px}
  .lesson-explain-rule{width:100%}
  .concept-motion{border-radius:20px}
  .concept-motion-head{display:block;padding:14px}
  .concept-motion-head p{margin-top:7px}
  .concept-motion-controls{grid-template-columns:1fr;padding:11px}
  .concept-motion-stage svg{min-height:220px}
}

/* Pass 34 — course path cards become visual chapter exhibits on phone */
.chapter-card{position:relative;overflow:hidden}
.chapter-card-art{width:138px;min-width:138px;align-self:stretch;border-right:1px solid var(--line);background:var(--field)}
.chapter-card-art svg{display:block;width:100%;height:100%;min-height:154px;object-fit:contain}
.chapter-card--visual{display:grid;grid-template-columns:138px minmax(0,1fr);padding:0!important}
.chapter-card--visual .chapter-index{position:absolute;left:10px;top:10px;z-index:2;width:30px;height:30px;border-radius:50%;display:grid;place-items:center;background:var(--panel);border:1px solid var(--line);box-shadow:0 5px 14px rgba(0,0,0,.18)}
.chapter-card--visual .chapter-body{padding:17px 17px 16px;min-width:0}
@media(max-width:720px){
  .chapter-card--visual{grid-template-columns:112px minmax(0,1fr);min-height:150px}
  .chapter-card-art{width:112px;min-width:112px}
  .chapter-card-art svg{min-height:150px}
  .chapter-card--visual .chapter-body{padding:14px 13px 13px}
  .chapter-card--visual .chapter-top{display:block}
  .chapter-card--visual .chapter-top h3{font-size:17px;line-height:1.08}
  .chapter-card--visual .chapter-state{display:inline-flex;margin-top:7px}
  .chapter-card--visual .chapter-top p{display:none}
}

/* Board palettes are product chrome, not permanently olive. */
:root{
 --board-bg:var(--art-base-deep);--board-hole:var(--art-base-line);--board-dim:var(--art-base-line);--board-mid:var(--art-base-accent);--board-live:var(--volt);--board-text:var(--volt);--board-sub:var(--muted);--board-gold:var(--warning);
}
:root[data-theme="day"]{
 --board-bg:var(--art-base-surface);--board-hole:var(--art-base-line);--board-dim:var(--art-base-line);--board-mid:var(--day-blue);--board-live:var(--day-red);--board-text:var(--day-navy);--board-sub:var(--muted);--board-gold:var(--warning);
}

/* Pass 34 — phone lesson deck */
@media(max-width:720px){
  .lesson-pager{touch-action:pan-y}
  .lesson-concept-nav{position:sticky;bottom:calc(8px + env(safe-area-inset-bottom));z-index:20;margin:22px -6px 0;padding:8px;background:color-mix(in srgb,var(--panel) 92%,transparent);border:1px solid var(--line);border-radius:18px;backdrop-filter:blur(14px);box-shadow:0 12px 34px rgba(0,0,0,.22)}
  .lesson-concept-nav .lesson-nav-next{min-height:50px;flex:1}
  .lesson-concept-nav .lesson-nav-back{min-height:50px}
}

/* Pass 35 — lesson blueprint rail + denser engineering exhibit hierarchy */
.lesson-concept-rail{display:flex;gap:8px;overflow-x:auto;overscroll-behavior-inline:contain;scroll-snap-type:x proximity;padding:4px 2px 12px;margin:-2px 0 4px;scrollbar-width:thin}
.lesson-concept-rail-item{scroll-snap-align:center;display:grid;grid-template-columns:auto minmax(72px,150px);align-items:center;gap:7px;min-height:42px;padding:7px 10px;border:1px solid var(--line);border-radius:13px;background:var(--panel);color:var(--muted);text-align:left;white-space:nowrap}
.lesson-concept-rail-item.on{border-color:var(--volt);background:color-mix(in srgb,var(--volt) 10%,var(--panel));color:var(--text);box-shadow:0 7px 22px rgba(0,0,0,.12)}
.lesson-concept-rail-item:hover{border-color:color-mix(in srgb,var(--volt) 60%,var(--line))}
.lesson-concept-rail-num{font:850 10px/1 var(--mono);letter-spacing:.05em;color:var(--volt)}
.lesson-concept-rail-label{overflow:hidden;text-overflow:ellipsis;font:720 11px/1.15 var(--sans)}
.concept-motion--pass35 .concept-motion-kicker{color:var(--editorial-red,var(--volt))}
.concept-motion--pass35 .concept-motion-head{background:linear-gradient(90deg,color-mix(in srgb,var(--panel) 96%,transparent),color-mix(in srgb,var(--volt) 4%,var(--panel)))}
@media(max-width:720px){.lesson-concept-rail{margin-inline:-3px;padding-bottom:9px}.lesson-concept-rail-item{grid-template-columns:auto minmax(66px,118px);min-height:38px;padding:6px 8px}.lesson-concept-rail-label{font-size:10px}}

/* Pass 36 — make hands-on density visible at the course-path level. */
.chapter-experience-meta{align-items:center;flex-wrap:wrap}
.chapter-experiment-chip{display:inline-flex;align-items:center;gap:5px;padding:4px 8px;border-radius:999px;border:1px solid color-mix(in srgb,var(--volt) 42%,var(--line));background:color-mix(in srgb,var(--volt) 8%,var(--panel));color:var(--text);font:800 10px/1 var(--mono);text-transform:uppercase;letter-spacing:.04em}
.chapter-experiment-chip::before{content:'↔';color:var(--volt);font-size:12px}
:root[data-theme="day"] .chapter-experiment-chip{border-color:color-mix(in srgb,var(--day-blue) 34%,var(--line));background:color-mix(in srgb,var(--day-blue) 6%,var(--panel));color:var(--day-navy)}
:root[data-theme="day"] .chapter-experiment-chip::before{color:var(--day-red)}
.pass36-bespoke-exhibit{border:1px solid color-mix(in srgb,var(--volt) 32%,var(--line));border-radius:22px;overflow:hidden;background:var(--panel);box-shadow:0 18px 42px rgba(0,0,0,.12)}
.pass36-bespoke-exhibit>.sim-controls{padding:12px 14px;border-top:1px solid var(--line)}

/* Pass 37 — failure-first mechanism exhibits. */
.pass37-bespoke-exhibit{border:1px solid color-mix(in srgb,var(--volt) 38%,var(--line));border-radius:22px;overflow:hidden;background:var(--panel);box-shadow:0 20px 46px rgba(0,0,0,.14)}
.pass37-bespoke-exhibit>.sim-controls{padding:12px 14px;border-top:1px solid var(--line)}
.exhibit-challenge{display:grid;grid-template-columns:auto 1fr;gap:10px;align-items:center;padding:11px 14px;border-top:1px solid var(--line);background:color-mix(in srgb,var(--volt) 6%,var(--panel))}
.exhibit-challenge span{font:900 9px/1 var(--mono);letter-spacing:.08em;color:var(--volt);white-space:nowrap}
.exhibit-challenge strong{font:650 11px/1.35 var(--sans);color:var(--text)}
:root[data-theme="day"] .exhibit-challenge{background:color-mix(in srgb,var(--day-blue) 5%,var(--panel))}
:root[data-theme="day"] .exhibit-challenge span{color:var(--day-red)}
@media(max-width:720px){.exhibit-challenge{grid-template-columns:1fr;gap:5px;padding:10px 11px}}

/* Pass 40 · hidden-root-cause virtual engineering bench */
.diag-hero{margin:28px 0 18px;padding:clamp(20px,4vw,42px);border:1px solid var(--line);border-radius:28px;background:linear-gradient(145deg,var(--surface),var(--surface2));overflow:hidden}.diag-hero h1{max-width:840px;margin:.18em 0}.diag-contract{display:flex;gap:14px;align-items:center;flex-wrap:wrap;margin-top:18px;padding:14px 16px;border:1px solid var(--line);border-radius:16px;background:var(--bg)}.diag-contract span{color:var(--muted);font-size:13px}.diag-scenario-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:10px;margin:18px 0}.diag-scenario-card{min-height:108px;text-align:left;padding:15px;border:1px solid var(--line);border-radius:18px;background:var(--surface);color:var(--ink);display:flex;flex-direction:column;gap:7px;align-items:flex-start;justify-content:flex-start}.diag-scenario-card strong{font-size:15px;line-height:1.15}.diag-scenario-card small{margin-top:auto;color:var(--muted);font-family:var(--mono)}.diag-scenario-card.on{border-color:var(--hot);box-shadow:inset 0 0 0 1px var(--hot)}.diag-page-mount{margin:16px 0 34px}.diag-bench{border:1px solid var(--line);border-radius:26px;background:var(--surface);padding:clamp(16px,3vw,28px);box-shadow:0 14px 46px rgba(0,0,0,.08)}.diag-bench-head{display:flex;gap:20px;justify-content:space-between;align-items:flex-start;margin-bottom:14px}.diag-bench-head h3{font-size:clamp(22px,4vw,34px);margin:.15em 0}.diag-bench-head p{max-width:760px;margin:.4em 0}.diag-score{min-width:82px;text-align:center;padding:11px;border:1px solid var(--line);border-radius:16px;background:var(--bg)}.diag-score strong{display:block;font:700 25px var(--mono);color:var(--hot)}.diag-score span{display:block;color:var(--muted);font-size:10px;text-transform:uppercase;letter-spacing:.08em}.diag-system{border:1px solid var(--line);border-radius:18px;overflow:hidden;background:var(--bg);margin:12px 0 18px}.diag-system svg{display:block;max-height:360px}.diag-probes,.diag-diagnoses,.diag-result{border-top:1px solid var(--line);padding-top:17px;margin-top:17px}.diag-stage-title{font:700 11px var(--mono);letter-spacing:.1em;text-transform:uppercase;color:var(--muted);margin-bottom:10px}.diag-probe,.diag-diagnosis{min-height:46px;border:1px solid var(--line);border-radius:13px;background:var(--bg);color:var(--ink);padding:10px 13px;margin:0 7px 8px 0;text-align:left}.diag-probe:hover,.diag-diagnosis:hover,.diag-probe:focus-visible,.diag-diagnosis:focus-visible{border-color:var(--hot)}.diag-probe.used{border-color:var(--read);color:var(--read)}.diag-reading{display:flex;justify-content:space-between;gap:14px;align-items:center;margin:0 0 8px;padding:10px 12px;border-left:3px solid var(--read);background:var(--bg);border-radius:0 12px 12px 0}.diag-reading span{color:var(--muted);font-size:12px}.diag-reading strong{font:600 12px var(--mono);text-align:right}.diag-result{border-color:var(--read)}.diag-result>strong{font-size:20px;color:var(--read)}.diag-result-meta{font:600 11px var(--mono);color:var(--muted);margin:12px 0}.diag-boundary{font-size:10px;color:var(--muted);margin:16px 0 0}.diag-philosophy{margin:34px 0;padding:24px;border-top:1px solid var(--line);border-bottom:1px solid var(--line)}.diag-bench-compact{padding:16px;border-radius:18px}.diag-bench-compact .diag-bench-head h3{font-size:22px}.diag-bench-compact .diag-system svg{max-height:260px}.diag-bench-compact .diag-boundary{display:none}
@media(max-width:900px){.diag-scenario-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.diag-bench-head{align-items:stretch}.diag-score{min-width:70px}.diag-reading{align-items:flex-start;flex-direction:column;gap:4px}.diag-reading strong{text-align:left}}
@media(max-width:560px){.diag-scenario-grid{display:flex;overflow-x:auto;scroll-snap-type:x mandatory;padding-bottom:4px}.diag-scenario-card{min-width:190px;scroll-snap-align:start}.diag-bench{padding:14px;border-radius:20px}.diag-bench-head{display:grid;grid-template-columns:1fr auto}.diag-bench-head p{grid-column:1/-1}.diag-system{margin-left:-4px;margin-right:-4px}.diag-probe,.diag-diagnosis{width:100%;margin-right:0}.diag-contract{display:block}.diag-contract span{display:block;margin-top:6px}}

/* Pass 41 · compound commissioning bench */
.commission-hero{position:relative}.commission-hero:after{content:'VERIFY';position:absolute;right:-8px;top:18px;font:800 clamp(56px,12vw,150px)/1 var(--display);letter-spacing:-.06em;color:var(--ink);opacity:.025;pointer-events:none}.commission-instruments,.commission-repair,.commission-verify{border-top:1px solid var(--line);padding-top:17px;margin-top:17px}.commission-instrument,.commission-action{min-height:48px;border:1px solid var(--line);border-radius:14px;background:var(--bg);color:var(--ink);padding:11px 14px;margin:0 8px 8px 0;text-align:left;font-weight:650}.commission-instrument:hover,.commission-action:hover,.commission-instrument:focus-visible,.commission-action:focus-visible{border-color:var(--hot)}.commission-instrument.used{border-color:var(--read);color:var(--read);box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--read) 28%,transparent)}.commission-probe-tray{margin:0 0 12px 18px;padding:10px 12px;border-left:2px solid var(--read);background:color-mix(in srgb,var(--surface2) 72%,transparent);border-radius:0 14px 14px 0}.commission-repair>strong{display:block;font-size:20px;color:var(--read);margin-bottom:6px}.commission-action{display:block;width:min(100%,780px)}.commission-verify{padding:18px;border:1px solid color-mix(in srgb,var(--hot) 30%,var(--line));border-radius:16px;background:color-mix(in srgb,var(--hot) 4%,var(--surface));}.commission-pass{border:1px solid color-mix(in srgb,var(--read) 40%,var(--line));border-radius:18px;padding:18px;background:color-mix(in srgb,var(--read) 4%,var(--surface))}.commission-pass>strong{font-size:24px}.commission-bench .diag-system svg{max-height:300px}
@media(max-width:560px){.commission-instrument,.commission-action{width:100%;margin-right:0}.commission-probe-tray{margin-left:7px;padding-left:9px}.commission-hero:after{display:none}.commission-verify{padding:14px}}

/* Pass 42 · Systems Bring-Up Lab */
.bringup-hero{position:relative}.bringup-hero:after{content:'BRING-UP';position:absolute;right:-12px;top:14px;font:800 clamp(52px,10vw,132px)/1 var(--display);letter-spacing:-.06em;color:var(--ink);opacity:.025;pointer-events:none}.bringup-state-panel,.bringup-hypotheses{border-top:1px solid var(--line);padding-top:17px;margin-top:17px}.bringup-state-row{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px}.bringup-state{min-height:88px;text-align:left;border:1px solid var(--line);border-radius:15px;background:var(--bg);color:var(--ink);padding:12px}.bringup-state strong{display:block;font:700 11px var(--mono);letter-spacing:.08em}.bringup-state small{display:block;color:var(--muted);font-size:11px;line-height:1.35;margin-top:7px}.bringup-state.on{border-color:var(--read);box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--read) 35%,transparent);background:color-mix(in srgb,var(--read) 5%,var(--bg))}.bringup-hypothesis{margin:0 0 10px}.bringup-hypothesis-label{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:3px 12px;align-items:end}.bringup-hypothesis-label strong{font-size:13px}.bringup-hypothesis-label small{grid-column:1;color:var(--muted);font:500 10px var(--mono);text-transform:uppercase;letter-spacing:.06em}.bringup-hypothesis-label b{grid-column:2;grid-row:1/3;font:700 13px var(--mono);color:var(--read)}.bringup-confidence{height:7px;border-radius:999px;background:var(--line);overflow:hidden;margin-top:6px}.bringup-confidence span{display:block;height:100%;border-radius:inherit;background:var(--read);transition:width .22s ease}.bringup-required-state{font:650 11px var(--mono);color:var(--hot);margin:8px 0 13px}.bringup-bench .commission-action:disabled,.bringup-bench .diag-probe:disabled{opacity:.47;cursor:not-allowed}.bringup-bench .diag-system svg{max-height:290px}
@media(max-width:650px){.bringup-state-row{grid-template-columns:1fr}.bringup-state{min-height:0}.bringup-hero:after{display:none}.bringup-hypothesis-label{grid-template-columns:minmax(0,1fr) auto}}

/* Pass 43 — Evidence & Test Planning Lab */
.evidence-hero{position:relative}.evidence-hero:after{content:'EVIDENCE';position:absolute;right:-10px;top:14px;font:800 clamp(48px,10vw,128px)/1 var(--display);letter-spacing:-.06em;color:var(--ink);opacity:.025;pointer-events:none}.evidence-bench{border:1px solid var(--line);border-radius:26px;background:var(--surface);padding:clamp(16px,3vw,28px);box-shadow:0 14px 46px rgba(0,0,0,.08)}.evidence-bench.compact{border-radius:18px;padding:16px}.evidence-planner,.evidence-plan-locked,.evidence-run,.evidence-history,.evidence-reading-card,.evidence-tree{border-top:1px solid var(--line);padding-top:17px;margin-top:17px}.evidence-plan-seq{display:flex;flex-wrap:wrap;gap:7px;margin:10px 0 14px}.evidence-plan-chip{border:1px solid var(--read);background:color-mix(in srgb,var(--read) 6%,var(--bg));color:var(--ink);border-radius:999px;padding:8px 11px;font:600 10px var(--mono)}.evidence-plan-choices{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin-bottom:12px}.evidence-plan-choices .commission-instrument{margin:0;width:100%;display:flex;flex-direction:column;gap:5px}.evidence-plan-choices small{color:var(--muted);font:500 10px var(--mono)}.evidence-plan-locked{display:grid;gap:6px}.evidence-plan-row{display:grid;grid-template-columns:28px minmax(0,1fr) auto auto;gap:9px;align-items:center;padding:9px 11px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.evidence-plan-row.on{border-color:var(--hot);box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--hot) 30%,transparent)}.evidence-plan-row b{font:700 11px var(--mono);color:var(--hot)}.evidence-plan-row small,.evidence-plan-row em{color:var(--muted);font:500 9px var(--mono);font-style:normal}.evidence-measure-controls{display:flex;gap:8px;flex-wrap:wrap;margin:12px 0}.evidence-reading-card{display:grid;grid-template-columns:minmax(120px,1fr) minmax(220px,1.4fr);gap:16px;align-items:end}.evidence-samples{height:92px;display:flex;align-items:flex-end;gap:7px;padding:8px;border:1px solid var(--line);border-radius:14px;background:var(--bg)}.evidence-sample-dot{display:block;flex:1;height:var(--eh);min-height:4px;border-radius:5px 5px 2px 2px;background:var(--read);opacity:.75;transition:height .2s ease}.evidence-reading-stats{display:grid;gap:5px}.evidence-reading-stats strong{font:650 13px var(--mono)}.evidence-reading-stats span,.evidence-reading-stats small{color:var(--muted);font-size:11px}.evidence-intermittent{color:var(--hot);font:700 10px var(--mono);letter-spacing:.05em}.evidence-tree-root{padding:13px 15px;border:1px solid var(--line);border-radius:14px;background:var(--bg);font-weight:650}.evidence-tree-branches{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px;margin-top:9px}.evidence-tree-branch{position:relative;padding:11px;border:1px solid var(--line);border-radius:13px;background:var(--bg);min-height:105px}.evidence-tree-branch:before{content:'';position:absolute;left:50%;top:-10px;width:1px;height:9px;background:var(--line)}.evidence-tree-branch small{display:block;color:var(--muted);font:600 9px var(--mono);text-transform:uppercase}.evidence-tree-branch strong{display:block;font-size:12px;line-height:1.25;margin:5px 0 9px}.evidence-tree-branch b{font:700 10px var(--mono);color:var(--read)}.evidence-tree-branch.active{border-color:var(--hot);background:color-mix(in srgb,var(--hot) 4%,var(--bg))}.evidence-history svg{display:block;width:100%;max-height:230px;border:1px solid var(--line);border-radius:14px}.evidence-timeline{display:grid;gap:5px;margin-top:10px}.evidence-event{display:grid;grid-template-columns:34px minmax(0,1fr) minmax(110px,auto) minmax(130px,auto);gap:8px;align-items:center;padding:8px 10px;border:1px solid var(--line);border-radius:11px;background:var(--bg)}.evidence-event b{color:var(--hot);font:700 10px var(--mono)}.evidence-event span{font-size:11px}.evidence-event code,.evidence-event small{font:500 9px var(--mono);color:var(--muted)}.diag-diagnosis.selected{border-color:var(--read);color:var(--read);box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--read) 30%,transparent)}
@media(max-width:700px){.evidence-tree-branches{grid-template-columns:repeat(2,minmax(0,1fr))}.evidence-plan-choices{grid-template-columns:1fr}.evidence-reading-card{grid-template-columns:1fr}.evidence-event{grid-template-columns:28px 1fr}.evidence-event code,.evidence-event small{grid-column:2}.evidence-plan-row{grid-template-columns:24px 1fr}.evidence-plan-row small,.evidence-plan-row em{grid-column:2}.evidence-hero:after{display:none}}

/* Pass 44 — Engineering Notebook & Commissioning Report */
.notebook-hero{position:relative}.notebook-hero:after{content:'NOTEBOOK';position:absolute;right:-12px;top:14px;font:800 clamp(48px,10vw,128px)/1 var(--display);letter-spacing:-.06em;color:var(--ink);opacity:.025;pointer-events:none}.notebook-layout{display:grid;grid-template-columns:minmax(220px,300px) minmax(0,1fr);gap:18px;align-items:start;margin:18px 0 36px}.notebook-list{display:grid;gap:8px;position:sticky;top:86px;max-height:calc(100vh - 110px);overflow:auto;padding-right:2px}.notebook-report-card{width:100%;text-align:left;border:1px solid var(--line);border-radius:15px;background:var(--surface);color:var(--ink);padding:13px;display:flex;flex-direction:column;gap:6px}.notebook-report-card strong{font-size:13px;line-height:1.25}.notebook-report-card small{color:var(--muted);font:500 9px var(--mono)}.notebook-report-card.on{border-color:var(--read);box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--read) 35%,transparent);background:color-mix(in srgb,var(--read) 4%,var(--surface))}.notebook-detail{min-width:0}.notebook-report{border:1px solid var(--line);border-radius:25px;background:var(--surface);padding:clamp(17px,3vw,30px);box-shadow:0 14px 46px rgba(0,0,0,.07)}.notebook-report-head{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:start}.notebook-report-head h1{margin:.15em 0;font-size:clamp(26px,4vw,42px)}.notebook-status{min-width:94px;padding:12px;border:1px solid var(--line);border-radius:15px;text-align:center;background:var(--bg)}.notebook-status strong{display:block;font:750 11px var(--mono);letter-spacing:.08em}.notebook-status span{display:block;font:700 23px var(--mono);margin-top:5px}.notebook-status.pass{border-color:color-mix(in srgb,var(--read) 50%,var(--line));color:var(--read)}.notebook-status.fail{border-color:color-mix(in srgb,var(--hot) 50%,var(--line));color:var(--hot)}.notebook-meta{display:flex;gap:8px;flex-wrap:wrap;margin:12px 0 16px}.notebook-meta span{border:1px solid var(--line);border-radius:999px;padding:6px 9px;color:var(--muted);font:550 9px var(--mono)}.notebook-actions{display:flex;gap:8px;flex-wrap:wrap;margin:14px 0 6px}.notebook-actions button{min-height:40px}.danger-ghost{border-color:color-mix(in srgb,var(--hot) 35%,var(--line));color:var(--hot)}.notebook-section,.notebook-critique{border-top:1px solid var(--line);padding-top:18px;margin-top:18px}.notebook-plan{display:grid;gap:7px}.notebook-plan-row{display:grid;grid-template-columns:34px minmax(0,1fr) auto;gap:9px;align-items:center;padding:10px 12px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.notebook-plan-row b{font:700 10px var(--mono);color:var(--hot)}.notebook-plan-row span{font-size:12px;font-weight:650}.notebook-plan-row small{font:500 9px var(--mono);color:var(--muted);text-align:right}.notebook-measurements{display:grid;gap:7px}.notebook-measurement{display:grid;grid-template-columns:38px minmax(0,1fr);gap:9px;padding:11px 12px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.notebook-measurement>b{color:var(--hot);font:700 9px var(--mono)}.notebook-measurement strong,.notebook-measurement small,.notebook-measurement code{display:block}.notebook-measurement strong{font-size:12px}.notebook-measurement small{color:var(--muted);font:500 9px var(--mono);margin:3px 0 5px}.notebook-measurement code{color:var(--read);font:550 10px var(--mono);white-space:normal}.notebook-measurement p{margin:6px 0 0;font-size:10px}.notebook-confidence{display:grid;gap:5px}.notebook-confidence-step{display:grid;grid-template-columns:30px minmax(0,1fr) minmax(150px,auto);gap:8px;align-items:center;padding:8px 10px;border-left:2px solid var(--read);background:var(--bg);border-radius:0 10px 10px 0}.notebook-confidence-step b{font:700 9px var(--mono);color:var(--hot)}.notebook-confidence-step span{font-size:10px}.notebook-confidence-step small{font:500 9px var(--mono);color:var(--muted);text-align:right}.notebook-repairs{display:grid;gap:7px;margin:10px 0}.notebook-repairs>div{display:flex;justify-content:space-between;gap:12px;padding:9px 11px;border:1px solid var(--line);border-radius:11px;background:var(--bg)}.notebook-repairs strong{font-size:11px}.notebook-repairs small{color:var(--muted);font:500 9px var(--mono);text-align:right}.notebook-accept-pass{color:var(--read);font-weight:700}.notebook-critique{padding:20px;border:1px solid color-mix(in srgb,var(--hot) 26%,var(--line));border-radius:18px;background:color-mix(in srgb,var(--hot) 3%,var(--surface))}.notebook-critique h2{font-size:clamp(21px,3vw,30px);margin:.2em 0 .35em}.notebook-compare{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin:15px 0}.notebook-compare>div{padding:11px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.notebook-compare small,.notebook-compare strong{display:block}.notebook-compare small{font:600 8px var(--mono);letter-spacing:.08em;color:var(--muted)}.notebook-compare strong{font:750 20px var(--mono);margin-top:5px;color:var(--read)}.notebook-advice{margin-top:12px;padding-left:13px;border-left:2px solid var(--read)}.notebook-advice>b{font:700 9px var(--mono);letter-spacing:.08em;color:var(--read)}.notebook-advice p{margin:5px 0;font-size:11px}.notebook-empty{min-height:300px;border:1px dashed var(--line);border-radius:22px;padding:clamp(24px,5vw,50px);display:flex;flex-direction:column;align-items:flex-start;justify-content:center;background:var(--surface)}
@media(max-width:820px){.notebook-layout{grid-template-columns:1fr}.notebook-list{position:static;display:flex;overflow-x:auto;scroll-snap-type:x mandatory;max-height:none;padding-bottom:5px}.notebook-report-card{min-width:210px;scroll-snap-align:start}.notebook-report-head{grid-template-columns:1fr auto}.notebook-plan-row{grid-template-columns:28px 1fr}.notebook-plan-row small{grid-column:2;text-align:left}.notebook-confidence-step{grid-template-columns:26px 1fr}.notebook-confidence-step small{grid-column:2;text-align:left}.notebook-hero:after{display:none}}
@media(max-width:520px){.notebook-report{margin-left:-4px;margin-right:-4px;padding:14px;border-radius:19px}.notebook-status{min-width:78px}.notebook-actions button{flex:1 1 44%}.notebook-compare{grid-template-columns:1fr}.notebook-repairs>div{display:grid}.notebook-repairs small{text-align:left}}
@media print{body{background:#fff!important;color:#000!important}.app-header,.bottom-nav,.notebook-list,.notebook-actions,.diag-hero,footer{display:none!important}.wrap{max-width:none!important;padding:0!important}.notebook-layout{display:block!important}.notebook-report{box-shadow:none!important;border:0!important;padding:0!important;background:#fff!important}.notebook-section,.notebook-critique{break-inside:avoid;background:#fff!important}.notebook-report *{color:#000!important;border-color:#bbb!important}.notebook-status.pass{border:1px solid #000!important}}

/* Pass 45 — app-first lab notebook, native-safe evidence capture */
button,a,input,select,textarea{-webkit-tap-highlight-color:transparent}
body.is-native{overscroll-behavior-y:none;-webkit-touch-callout:none}
body.is-native input,body.is-native select,body.is-native textarea{font-size:16px}
.lab-resume-chip{display:inline-flex;align-items:center;min-height:34px;margin:0 0 10px;padding:6px 10px;border:1px solid color-mix(in srgb,var(--read) 40%,var(--line));border-radius:999px;background:color-mix(in srgb,var(--read) 6%,var(--surface));color:var(--read);font:700 9px/1 var(--mono);letter-spacing:.06em}
.evidence-plan-specs{display:grid;gap:9px;margin:14px 0}.evidence-plan-spec{display:grid;grid-template-columns:minmax(150px,1fr) minmax(160px,1.1fr) minmax(150px,.9fr) minmax(150px,.9fr);gap:8px;align-items:center;padding:11px;border:1px solid var(--line);border-radius:14px;background:var(--bg)}.evidence-plan-spec>b{font-size:11px}.evidence-plan-spec input,.evidence-plan-spec select,.evidence-preflight-contract textarea,.evidence-observation,.bringup-observation{width:100%;min-height:46px;border:1px solid var(--line);border-radius:11px;background:var(--field);color:var(--text);padding:10px 11px;font:500 12px/1.35 var(--sans)}.evidence-preflight-contract{display:grid;grid-template-columns:1fr 1fr;gap:8px;margin:13px 0}.evidence-preflight-contract>.diag-stage-title{grid-column:1/-1}.evidence-observation,.bringup-observation{margin:8px 0 2px;resize:vertical;min-height:68px}.commission-probe-tray .bringup-observation{flex:1 1 100%}
.notebook-preflight{display:grid;grid-template-columns:1fr 1fr;gap:9px}.notebook-preflight>.diag-stage-title{grid-column:1/-1}.notebook-contract{padding:13px;border:1px solid color-mix(in srgb,var(--read) 38%,var(--line));border-radius:13px;background:color-mix(in srgb,var(--read) 4%,var(--bg))}.notebook-contract.stop{border-color:color-mix(in srgb,var(--hot) 38%,var(--line));background:color-mix(in srgb,var(--hot) 4%,var(--bg))}.notebook-contract>b{display:block;font:750 9px var(--mono);letter-spacing:.08em;color:var(--read)}.notebook-contract.stop>b{color:var(--hot)}.notebook-contract p{font-size:11px;margin:6px 0 0}.notebook-observations{display:grid;gap:7px}.notebook-observations article{padding:11px 12px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.notebook-observations b{font:700 10px var(--mono);color:var(--read)}.notebook-observations p{margin:5px 0 0;font-size:12px}.notebook-evidence-attach{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px;margin:10px 0}.notebook-evidence-attach select{min-height:46px;border:1px solid var(--line);border-radius:11px;background:var(--field);color:var(--text);padding:0 11px}.notebook-evidence-links{display:grid;gap:6px}.notebook-evidence-links>div{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:9px 11px;border:1px solid var(--line);border-radius:11px;background:var(--bg)}.notebook-evidence-links span{font-size:11px;font-weight:650}.notebook-evidence-links button{min-height:36px;padding:7px 10px;font-size:9px}
.fasttrack-evidence{margin:2px 0 10px;padding:18px 20px;border:1px dashed var(--line);border-radius:22px;background:var(--panel)}.fasttrack-evidence.has-evidence{border-style:solid;border-color:color-mix(in srgb,var(--read) 42%,var(--line));background:color-mix(in srgb,var(--read) 3%,var(--panel))}.fasttrack-evidence-head{display:flex;align-items:flex-start;justify-content:space-between;gap:12px}.fasttrack-evidence-head h2{margin:3px 0 0;font-size:22px}.fasttrack-evidence-head>a{font:700 10px var(--mono);white-space:nowrap}.fasttrack-evidence-list{display:grid;gap:7px;margin-top:12px}.fasttrack-evidence-list>a{display:flex;justify-content:space-between;gap:12px;padding:10px 11px;border:1px solid var(--line);border-radius:12px;background:var(--bg);color:var(--text)}.fasttrack-evidence-list strong{font-size:11px}.fasttrack-evidence-list span{color:var(--muted);font:550 9px var(--mono)}
@media(max-width:820px){.evidence-plan-spec{grid-template-columns:1fr}.evidence-preflight-contract{grid-template-columns:1fr}.notebook-preflight{grid-template-columns:1fr}.notebook-preflight>.diag-stage-title{grid-column:auto}.fasttrack-evidence-head{display:grid}.fasttrack-evidence-list>a{display:grid}.notebook-evidence-attach{grid-template-columns:1fr}.notebook-evidence-attach button{width:100%}}
@media(max-width:620px){body.is-native .notebook-actions,body.is-standalone .notebook-actions{position:sticky;bottom:calc(72px + env(safe-area-inset-bottom,0px));z-index:30;margin-left:-6px;margin-right:-6px;padding:7px;border:1px solid var(--line);border-radius:16px;background:color-mix(in srgb,var(--bg) 94%,transparent);backdrop-filter:blur(18px)}body.is-native .notebook-actions button,body.is-standalone .notebook-actions button{min-height:48px}.notebook-evidence-links>div{display:grid}.notebook-evidence-links button{width:max-content}}


/* Pass 46 — touch is the baseline input across web/PWA + Android + iOS. */
@media (pointer:coarse){
  button,select,[role="button"],.lesson-watch-chip,.mech-showcase-controls button,.mech-showcase-controls select{min-height:44px}
  input[type="range"]{min-height:44px;touch-action:pan-y}
  .bb-item,.course-category-tab,.notebook-report-card{min-height:44px}
}
:root[data-runtime^="native-"] .app-content{padding-left:max(0px,env(safe-area-inset-left));padding-right:max(0px,env(safe-area-inset-right))}
@media(prefers-reduced-motion:reduce){html:focus-within{scroll-behavior:auto}.shell-navigating,.shell-leaving{transition:none!important}}

/* Pass 48 — mobile interaction, keyboard, focus and reduced-motion hardening. */
:root{--keyboard-inset:0px;--app-visual-width:100vw}
:where(button,a,input,select,textarea,[role="button"],[tabindex]):focus-visible{outline:3px solid var(--read);outline-offset:3px}
:where(.anim,.concept-motion,.sandbox-shell) svg{max-width:100%;touch-action:pan-y}
body.keyboard-open .bottombar{transform:translateY(calc(100% + env(safe-area-inset-bottom,0px)));pointer-events:none}
body.keyboard-open .notebook-actions{bottom:12px!important}
body.keyboard-open .app-content{padding-bottom:max(18px,var(--keyboard-inset))}
@media(pointer:coarse){
  :where(button,.btn,a.bb-item,[role="button"],select,input[type="checkbox"],input[type="radio"]){min-height:44px}
  :where(button,.btn,a.bb-item,[role="button"]){touch-action:manipulation}
  input[type="range"]{height:44px;min-height:44px;touch-action:pan-y}
  .controls{row-gap:10px}
  .controls>button,.controls>.btn{min-width:44px}
}
@media(max-width:720px){
  .anim,.concept-motion,.sandbox-shell{scroll-margin-top:12px}
  input,select,textarea{scroll-margin-bottom:calc(96px + var(--keyboard-inset))}
}
@media(prefers-reduced-motion:reduce){
  *,*::before,*::after{scroll-behavior:auto!important;animation-duration:.001ms!important;animation-iteration-count:1!important;transition-duration:.001ms!important}
  .shell-navigating,.shell-leaving{transition:none!important}
}

/* Pass 53 — Virtual BCI Research Bench: same replay, predeclare, lock, test, explain. */
.bci-research-hero{position:relative;overflow:hidden;margin:18px 0 16px;padding:clamp(24px,5vw,52px);border:1px solid var(--line);border-radius:28px;background:linear-gradient(135deg,color-mix(in srgb,var(--read) 8%,var(--surface)),var(--surface));box-shadow:0 22px 60px rgba(0,0,0,.12)}
.bci-research-hero:after{content:"";position:absolute;right:-50px;top:-65px;width:270px;height:270px;border:34px solid color-mix(in srgb,var(--volt) 15%,transparent);border-radius:50%;pointer-events:none}
.bci-research-hero h1{max-width:850px;margin:.18em 0 .35em;font-size:clamp(35px,6vw,68px);line-height:.94}
.bci-research-main{display:grid;gap:14px;margin-bottom:28px}
.bci-research-panel{padding:clamp(18px,3vw,28px);border:1px solid var(--line);border-radius:22px;background:var(--surface);box-shadow:0 14px 34px rgba(0,0,0,.07)}
.bci-research-panel h2{margin:.18em 0 .55em;font-size:clamp(22px,3.5vw,34px)}
.bci-research-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin:12px 0}
.bci-research-toolbar select,.bci-research-toolbar .btn,.bci-research-lock button{min-height:44px}
.bci-research-toolbar select{min-width:190px;padding:0 11px;border:1px solid var(--line);border-radius:11px;background:var(--field);color:var(--text)}
.bci-stress-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;margin:14px 0}
.bci-stress-grid label{display:grid;gap:5px;padding:10px 12px;border:1px solid var(--line);border-radius:13px;background:var(--bg)}
.bci-stress-grid label>span{display:flex;justify-content:space-between;gap:10px;font:650 10px var(--mono);color:var(--muted)}
.bci-stress-grid label b{color:var(--text)}
.bci-stress-grid input[type="range"]{width:100%}
.bci-pipeline-table{display:grid;gap:6px;margin:14px 0}.bci-pipeline-row{display:grid;grid-template-columns:minmax(190px,1.6fr) repeat(4,minmax(78px,.7fr));gap:8px;align-items:center;width:100%;min-height:54px;padding:9px 11px;border:1px solid var(--line);border-radius:13px;background:var(--bg);color:var(--text);text-align:left}.bci-pipeline-row button{width:100%}.bci-pipeline-row>span:first-child{display:grid}.bci-pipeline-row small{margin-top:3px;color:var(--muted);font:600 8px var(--mono);letter-spacing:.06em}.bci-pipeline-row strong{font:750 15px var(--mono);color:var(--read)}.bci-pipeline-row.head{min-height:auto;border:0;background:transparent;color:var(--muted);font:650 8px var(--mono);letter-spacing:.08em;text-transform:uppercase}.bci-pipeline-row.on{border-color:color-mix(in srgb,var(--read) 58%,var(--line));box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--read) 34%,transparent)}.bci-pipeline-row.candidate{border-color:color-mix(in srgb,var(--volt) 62%,var(--line))}.bci-pipeline-row.best{background:color-mix(in srgb,var(--read) 5%,var(--bg))}
.bci-research-lock{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:10px;align-items:center;padding:13px;border:1px solid color-mix(in srgb,var(--volt) 35%,var(--line));border-radius:15px;background:color-mix(in srgb,var(--volt) 3%,var(--bg))}.bci-research-lock>div{display:grid;gap:4px}.bci-research-lock span{color:var(--muted);font:500 9px var(--mono)}
.bci-postmortem,.bci-research-metrics{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin:12px 0}.bci-research-metrics{grid-template-columns:repeat(5,minmax(0,1fr))}.bci-metric{display:grid;gap:3px;padding:10px 11px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.bci-metric small{font:650 8px var(--mono);letter-spacing:.06em;color:var(--muted);text-transform:uppercase}.bci-metric strong{font:750 18px var(--mono);color:var(--read)}.bci-metric span{font-size:9px;color:var(--muted)}
.bci-trial-slider{display:grid;gap:7px;margin:10px 0}.bci-trial-slider>span{font:650 10px var(--mono);color:var(--muted)}.bci-wave-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}.bci-wave{position:relative;min-height:140px;padding:10px;border:1px solid var(--line);border-radius:15px;background:var(--bg);color:var(--volt)}.bci-wave.c4{color:var(--read)}.bci-wave svg{display:block;width:100%;height:auto}.bci-wave small{position:absolute;left:12px;bottom:8px;font:650 8px var(--mono);color:var(--muted)}
.bci-trial-preds{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:7px;margin:10px 0}.bci-trial-preds>div{display:flex;justify-content:space-between;gap:10px;padding:9px 10px;border:1px solid var(--line);border-radius:11px;background:var(--bg)}.bci-trial-preds b{font:700 9px var(--mono)}.bci-trial-preds span{font:600 9px var(--mono);color:var(--muted)}.bci-trial-preds .good{border-color:color-mix(in srgb,var(--read) 45%,var(--line))}.bci-trial-preds .bad{border-color:color-mix(in srgb,var(--hot) 55%,var(--line));background:color-mix(in srgb,var(--hot) 4%,var(--bg))}.bci-trial-preds .abstain{border-style:dashed}
.bci-accept-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin:13px 0}.bci-accept-grid>div{display:grid;gap:5px;padding:12px;border:1px solid var(--line);border-radius:13px;background:var(--bg)}.bci-accept-grid b{font:800 9px var(--mono)}.bci-accept-grid span{font-size:11px;font-weight:700}.bci-accept-grid small{font:600 9px var(--mono);color:var(--muted)}.bci-accept-grid .pass{border-color:color-mix(in srgb,var(--read) 46%,var(--line))}.bci-accept-grid .pass b{color:var(--read)}.bci-accept-grid .fail{border-color:color-mix(in srgb,var(--hot) 55%,var(--line));background:color-mix(in srgb,var(--hot) 4%,var(--bg))}.bci-accept-grid .fail b{color:var(--hot)}
.bci-research-note{width:100%;min-height:120px;resize:vertical;border:1px solid var(--line);border-radius:14px;background:var(--field);color:var(--text);padding:13px;font:500 12px/1.45 var(--sans)}
.notebook-research-benchmark{padding:18px;border:1px solid color-mix(in srgb,var(--read) 35%,var(--line));border-radius:17px;background:color-mix(in srgb,var(--read) 3%,var(--surface))}.notebook-research-table{display:grid;gap:6px;margin-top:12px}.notebook-research-row{display:grid;grid-template-columns:minmax(145px,1.2fr) repeat(4,minmax(70px,.7fr));gap:8px;padding:9px 10px;border:1px solid var(--line);border-radius:11px;background:var(--bg);font:600 9px var(--mono)}.notebook-research-row.selected{border-color:color-mix(in srgb,var(--volt) 58%,var(--line))}.notebook-research-row.best{background:color-mix(in srgb,var(--read) 5%,var(--bg))}
@media(max-width:820px){.bci-stress-grid{grid-template-columns:1fr}.bci-pipeline-row{grid-template-columns:minmax(140px,1.3fr) repeat(2,minmax(72px,.7fr))}.bci-pipeline-row>:nth-child(4),.bci-pipeline-row>:nth-child(5){display:none}.bci-research-lock{grid-template-columns:1fr}.bci-research-lock button{width:100%}.bci-research-metrics{grid-template-columns:repeat(2,minmax(0,1fr))}.bci-wave-grid{grid-template-columns:1fr}.bci-trial-preds{grid-template-columns:repeat(2,minmax(0,1fr))}.bci-accept-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.notebook-research-row{grid-template-columns:minmax(120px,1.2fr) repeat(2,minmax(65px,.7fr))}.notebook-research-row>:nth-child(4),.notebook-research-row>:nth-child(5){display:none}}
@media(max-width:520px){.bci-research-hero{padding:22px 17px}.bci-research-panel{padding:16px 14px}.bci-postmortem,.bci-research-metrics,.bci-trial-preds,.bci-accept-grid{grid-template-columns:1fr}.bci-pipeline-row{grid-template-columns:minmax(120px,1.5fr) 70px 74px}.bci-pipeline-row>:nth-child(4),.bci-pipeline-row>:nth-child(5){display:none}.bci-research-toolbar>*{width:100%}.bci-research-toolbar select{min-width:0}.notebook-research-row{grid-template-columns:1fr 70px 70px}}
.course-research-lab{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:center;margin:12px 0 18px;padding:20px 22px;border:1px solid color-mix(in srgb,var(--read) 38%,var(--line));border-radius:22px;background:color-mix(in srgb,var(--read) 4%,var(--surface))}.course-research-lab h2{margin:.15em 0 .25em;font-size:clamp(22px,3vw,32px)}.course-research-lab p{margin:0;max-width:820px;color:var(--muted);font-size:12px;line-height:1.5}.course-research-lab .btn{white-space:nowrap}@media(max-width:720px){.course-research-lab{grid-template-columns:1fr;padding:17px}.course-research-lab .btn{width:100%;text-align:center}}

/* Pass 54 · foundations, prerequisite readiness, premium architecture */
.foundation-schema-art{min-height:120px;display:grid;place-items:center;border:1px solid var(--line);border-radius:18px;background:linear-gradient(145deg,color-mix(in srgb,var(--volt) 15%,var(--panel)),var(--panel));font:800 clamp(2.4rem,10vw,5.5rem)/1 var(--mono);letter-spacing:-.08em;color:var(--text)}
.foundation-category-intro,.foundation-policy-note,.premium-architecture-note{margin:14px 0 22px;padding:18px 20px;border:1px solid var(--line);border-radius:18px;background:var(--panel)}
.foundation-category-intro p,.foundation-policy-note p,.premium-architecture-note p{margin:6px 0 0;color:var(--muted);max-width:72ch}
.foundations-page,.premium-page{max-width:1180px;margin:0 auto;padding:10px 0 64px}
.foundations-hero,.premium-hero{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(180px,.4fr);gap:24px;align-items:end;margin:24px 0;padding:28px;border:1px solid var(--line);border-radius:24px;background:var(--panel)}
.foundations-hero h1,.premium-hero h1{font-size:clamp(2rem,5vw,4rem);letter-spacing:-.045em;margin:.2em 0}
.foundations-hero p,.premium-hero p{max-width:70ch;color:var(--muted);font-size:1.04rem}
.foundation-hero-meter{display:flex;flex-direction:column;align-items:flex-end}.foundation-hero-meter strong{font:700 clamp(3rem,8vw,6rem)/1 var(--mono)}.foundation-hero-meter span{color:var(--muted);text-align:right}
.track-readiness-panel,.foundation-lab,.foundation-roadmap-card,.premium-free-card,.premium-status-card,.premium-packs{margin:18px 0;padding:22px;border:1px solid var(--line);border-radius:22px;background:var(--panel)}
.track-readiness-panel{display:grid;grid-template-columns:1fr auto;gap:18px;align-items:start}.foundation-readiness-score{display:flex;flex-direction:column;align-items:flex-end}.foundation-readiness-score strong{font:700 2rem/1 var(--mono)}.foundation-readiness-score span{margin-top:5px;color:var(--muted);font-size:.78rem}
.foundation-missing-list{grid-column:1/-1;display:flex;gap:8px;flex-wrap:wrap}.foundation-missing-list a{padding:7px 10px;border:1px solid var(--line);border-radius:999px;color:var(--text);text-decoration:none;font-size:.84rem}
.foundation-roadmaps{display:grid;gap:20px}.foundation-roadmap-head{display:flex;justify-content:space-between;gap:20px}.foundation-roadmap-head p{color:var(--muted);max-width:72ch}.foundation-roadmap-count{white-space:nowrap;color:var(--muted);font:500 .8rem var(--mono)}
.foundation-stage{margin-top:22px}.foundation-stage h3{font-size:.85rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}.foundation-concept-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:10px}
.foundation-concept-card{display:block;padding:14px;border:1px solid var(--line);border-radius:16px;text-decoration:none;color:var(--text);background:color-mix(in srgb,var(--panel) 88%,var(--bg));min-height:135px}.foundation-concept-card.is-ready{border-color:color-mix(in srgb,var(--volt) 55%,var(--line))}.foundation-concept-card p{font-size:.84rem;color:var(--muted);line-height:1.45}.foundation-concept-top{display:flex;justify-content:space-between;gap:10px}.foundation-time{font:500 .72rem var(--mono);color:var(--muted)}
.foundation-status{display:inline-flex;align-items:center;height:22px;padding:0 7px;border:1px solid var(--line);border-radius:999px;font:600 .66rem var(--mono);letter-spacing:.05em}.foundation-status.is-ready{color:var(--volt);border-color:color-mix(in srgb,var(--volt) 55%,var(--line))}.foundation-status.is-gap{color:var(--muted)}
.foundation-lab-head{display:flex;justify-content:space-between;gap:20px}.foundation-prereq-line{color:var(--muted);font-size:.84rem}.foundation-prereq-line a{color:var(--text)}.foundation-diagnostic,.foundation-bridge{margin-top:18px;padding-top:18px;border-top:1px solid var(--line)}.foundation-answer-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.foundation-answer-grid button{text-align:left}.foundation-result{min-height:1.5em;font-weight:600}.foundation-result.good{color:var(--volt)}.foundation-result.bad{color:var(--muted)}.foundation-bridge ol{padding-left:1.4em;color:var(--muted);line-height:1.55}.foundation-example{margin:14px 0;padding:14px;border-left:3px solid var(--volt);background:color-mix(in srgb,var(--volt) 7%,transparent)}.foundation-example p{margin:6px 0 0}
.course-foundation-readiness{display:flex;justify-content:space-between;align-items:center;gap:18px;margin:12px 0 20px;padding:14px 18px;border:1px solid var(--line);border-radius:16px;background:var(--panel);text-decoration:none;color:var(--text)}.course-foundation-readiness p{margin:4px 0 0;color:var(--muted);font-size:.84rem}.course-foundation-readiness.is-ready{border-color:color-mix(in srgb,var(--volt) 50%,var(--line))}.foundation-readiness-ratio{font:700 1.15rem var(--mono);white-space:nowrap}
.lesson-foundation-banner{display:flex;justify-content:space-between;gap:18px;align-items:center;margin:10px 0 18px;padding:14px 18px;border:1px solid color-mix(in srgb,var(--volt) 28%,var(--line));border-radius:16px;background:color-mix(in srgb,var(--volt) 6%,var(--panel))}.lesson-foundation-banner p{margin:4px 0 0;color:var(--muted);font-size:.84rem}.lesson-foundation-actions{display:flex;gap:8px;flex-wrap:wrap;justify-content:flex-end}
.premium-mode-chip{display:inline-flex;margin-top:12px;padding:6px 9px;border:1px solid var(--line);border-radius:999px;font:600 .72rem var(--mono);color:var(--muted)}.premium-plan-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:18px 0}.premium-plan{padding:24px;border:1px solid var(--line);border-radius:22px;background:var(--panel)}.premium-plan.featured{border-color:color-mix(in srgb,var(--volt) 55%,var(--line));box-shadow:inset 0 0 0 1px color-mix(in srgb,var(--volt) 20%,transparent)}.premium-price{display:block;font:700 clamp(1.8rem,5vw,3rem)/1 var(--mono);margin:14px 0}.premium-equivalent{color:var(--muted);min-height:2.6em}.premium-free-card,.premium-status-card{display:flex;justify-content:space-between;gap:20px;align-items:center}.premium-free-card p,.premium-status-card p{color:var(--muted);max-width:66ch}.premium-pack-row{display:grid;grid-template-columns:2fr .8fr .8fr 1.2fr;gap:10px;padding:10px 0;border-top:1px solid var(--line);font-size:.84rem}.premium-pack-row span{color:var(--muted)}.membership-row{display:flex;justify-content:space-between;align-items:center;gap:16px}.membership-row>div{display:flex;flex-direction:column;gap:4px}.membership-row span{color:var(--muted)}.premium-gate{max-width:650px;margin:8vh auto;padding:28px;border:1px solid var(--line);border-radius:24px;background:var(--panel)}.premium-gate .btn{margin:8px 8px 0 0}
@media(max-width:720px){.foundations-page,.premium-page{padding-bottom:96px}.foundations-hero,.premium-hero{grid-template-columns:1fr;padding:20px}.foundation-hero-meter{align-items:flex-start}.foundation-hero-meter span{text-align:left}.foundation-roadmap-head,.foundation-lab-head,.premium-free-card,.premium-status-card,.membership-row{flex-direction:column;align-items:flex-start}.foundation-roadmap-head{display:flex}.foundation-concept-grid{grid-template-columns:1fr}.track-readiness-panel{grid-template-columns:1fr}.foundation-readiness-score{align-items:flex-start}.foundation-answer-grid,.premium-plan-grid{grid-template-columns:1fr}.lesson-foundation-banner{align-items:flex-start;flex-direction:column}.lesson-foundation-actions{justify-content:flex-start;width:100%}.lesson-foundation-actions .btn,.lesson-foundation-actions button{flex:1}.premium-pack-row{grid-template-columns:1.4fr .7fr}.premium-pack-row span:last-child{display:none}}

/* Pass 56 · deep math shelf */
.foundation-deep-shelf{margin:18px 0;padding:16px;border:1px solid var(--line);border-radius:16px;background:color-mix(in srgb,var(--panel) 88%,transparent)}
.foundation-deep-shelf h3{margin:0 0 12px}.foundation-deep-course-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.foundation-deep-course{display:flex;justify-content:space-between;gap:12px;align-items:center;padding:13px 14px;border:1px solid var(--line);border-radius:12px;text-decoration:none;background:var(--bg)}.foundation-deep-course span{font:600 11px/1 var(--mono);color:var(--muted);white-space:nowrap}@media(max-width:680px){.foundation-deep-course-grid{grid-template-columns:1fr}}

.course-deep-math-shelf{margin:18px 0;padding:18px;border:1px solid var(--line);border-radius:18px;background:var(--panel)}.course-deep-math-shelf>p{color:var(--muted);max-width:760px}.course-deep-math-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:14px}.course-deep-math-card{display:block;padding:15px;border:1px solid var(--line);border-radius:14px;text-decoration:none;background:var(--bg)}.course-deep-math-card strong{font-family:var(--display);font-size:17px}.course-deep-math-card p{color:var(--muted);margin:7px 0 10px}.course-deep-math-card span{font:600 11px/1 var(--mono);color:var(--volt)}@media(max-width:680px){.course-deep-math-grid{grid-template-columns:1fr}}

/* Pass 57 · mathematical intuition */
.course-intuition-lab,.math-intuition-contract{display:flex;justify-content:space-between;gap:18px;align-items:center;margin:18px 0;padding:18px;border:1px solid var(--line);border-radius:18px;background:var(--panel)}.math-intuition-contract p,.course-intuition-lab p{margin:.35rem 0 0;color:var(--muted)}.math-intuition-hero{padding:24px 0 12px}.math-intuition-tabs{display:flex;gap:8px;overflow:auto;padding:8px 0 16px;scrollbar-width:none}.math-intuition-tabs button{white-space:nowrap;border:1px solid var(--line);background:var(--panel);border-radius:999px;padding:10px 13px;color:var(--ink)}.math-intuition-tabs button.on{border-color:var(--volt);box-shadow:0 0 0 1px var(--volt) inset}.math-intuition-scene{border:1px solid var(--line);border-radius:20px;background:var(--panel);padding:18px;margin:0 0 24px}.math-intuition-stage{margin:14px 0;border:1px solid var(--line);border-radius:16px;overflow:hidden;background:var(--bg)}.math-intuition-svg{width:100%;display:block;min-height:260px}.math-intuition-controls{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.math-intuition-control{display:grid;gap:7px;padding:10px;border:1px solid var(--line);border-radius:12px}.math-intuition-control span{display:flex;justify-content:space-between;gap:10px}.math-predict{margin-top:14px;padding:14px;border-left:4px solid var(--volt);background:var(--bg)}.math-predict button{margin:8px 8px 0 0}.math-predict-result.good{color:var(--good)}.math-predict-result.bad{color:var(--danger)}.polya-cycle{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;padding:24px}.polya-cycle article{display:grid;gap:7px;padding:16px;border:1px solid var(--line);border-radius:16px}.polya-cycle b{font:700 26px/1 var(--mono);color:var(--volt)}.polya-cycle span{color:var(--muted);font-size:12px}.course-intuition-lab{margin-top:14px}@media(max-width:720px){.course-intuition-lab,.math-intuition-contract{align-items:flex-start;flex-direction:column}.math-intuition-controls{grid-template-columns:1fr}.polya-cycle{grid-template-columns:1fr 1fr;padding:14px}}

/* Pass 58 · lesson-level mathematical intuition */
.math-quality-panel{margin:16px 0 20px;padding:18px;border:1px solid var(--line);border-radius:22px;background:var(--panel);box-shadow:0 12px 34px rgba(0,0,0,.12)}
.math-quality-panel>h2{margin:3px 0 14px;font-size:clamp(1.2rem,3.4vw,1.65rem)}
.math-quality-prompt{font-weight:700;margin:0 0 10px;line-height:1.35}.math-quality-choice-grid{display:grid;gap:8px}
.math-quality-choice{min-height:46px;text-align:left;padding:10px 12px;border:1px solid var(--line);border-radius:14px;background:var(--surface);color:var(--ink);font:inherit}.math-quality-choice.on{outline:2px solid var(--volt);outline-offset:1px}.math-quality-feedback{min-height:22px;margin:8px 0 0;font-size:.88rem;color:var(--muted)}.math-quality-feedback.ok{color:var(--ok)}.math-quality-feedback.review{color:var(--hot)}
.math-quality-reps,.math-quality-break,.math-quality-choose,.math-quality-lookback{margin-top:18px;padding-top:16px;border-top:1px solid var(--line)}
.math-quality-sectionhead{display:flex;justify-content:space-between;gap:12px;align-items:baseline;margin-bottom:10px}.math-quality-sectionhead strong{font-size:1rem}.math-quality-sectionhead span{font-size:.78rem;color:var(--muted);text-align:right}
.math-quality-visual{padding:10px;border:1px solid var(--line);border-radius:16px;background:var(--surface);overflow:hidden}.math-quality-sketch{display:block;width:100%;max-height:225px;color:var(--ink)}.math-quality-visual input[type=range]{width:100%;margin:4px 0 0;touch-action:pan-y}
.math-quality-rep-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin-top:8px}.math-quality-rep{padding:11px;border:1px solid var(--line);border-radius:14px;background:color-mix(in srgb,var(--surface) 88%,var(--volt) 12%)}.math-quality-rep small{display:block;font-family:var(--mono);text-transform:uppercase;letter-spacing:.04em;color:var(--muted);font-size:.68rem}.math-quality-rep p{margin:5px 0 0;font-size:.88rem;line-height:1.35}
.math-quality-break blockquote{margin:8px 0 10px;padding:12px 14px;border-left:4px solid var(--hot);background:color-mix(in srgb,var(--surface) 90%,var(--hot) 10%);border-radius:0 12px 12px 0;font-weight:650}.math-quality-counter{min-height:20px;color:var(--ink);font-size:.9rem;line-height:1.4}
.math-quality-lookback textarea{width:100%;min-height:88px;resize:vertical;border:1px solid var(--line);border-radius:14px;background:var(--surface);color:var(--ink);padding:11px;font:inherit}.math-quality-lookback>p{margin:8px 0 10px;font-weight:650}
.math-predict-locked{position:relative}.math-predict-locked .lesson-watch-row,.math-predict-locked .lesson-concept-sim{pointer-events:none;filter:saturate(.25) opacity(.42)}.math-predict-lock{position:relative;z-index:2;margin:10px 0;padding:11px 12px;border:1px dashed var(--volt);border-radius:14px;background:var(--panel);display:flex;gap:8px;align-items:center;justify-content:space-between}.math-predict-lock strong{font-size:.82rem;text-transform:uppercase;letter-spacing:.05em}.math-predict-lock span{font-size:.82rem;color:var(--muted);text-align:right}
@media(max-width:620px){.math-quality-panel{padding:14px;border-radius:18px}.math-quality-rep-grid{grid-template-columns:1fr}.math-quality-sectionhead{display:block}.math-quality-sectionhead span{display:block;text-align:left;margin-top:3px}.math-predict-lock{display:block}.math-predict-lock span{display:block;text-align:left;margin-top:4px}}
@media(prefers-reduced-motion:reduce){.math-quality-choice,.math-quality-sketch{transition:none!important}}

/* Pass 59 · Math Mastery & Transfer */
.math-gym-page{display:grid;gap:18px;padding-bottom:40px}
.math-gym-hero,.math-gym-start,.math-gym-task,.math-gym-dimensions,.math-gym-misconceptions,.math-gym-skillmap{border:1px solid var(--line);background:var(--panel);border-radius:18px;padding:22px}
.math-gym-hero{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:22px;align-items:end;background:linear-gradient(145deg,var(--panel),color-mix(in srgb,var(--volt) 7%,var(--panel)))}
.math-gym-hero h1{max-width:820px;margin:.2rem 0 .6rem}.math-gym-hero-copy{min-width:0}.math-gym-metrics{display:grid;grid-template-columns:repeat(3,minmax(110px,1fr));gap:8px}
.math-gym-metric{display:grid;gap:2px;min-width:115px;padding:12px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.math-gym-metric strong{font:700 24px/1 var(--display)}.math-gym-metric span{font-size:12px}.math-gym-metric small{color:var(--muted);font:10px/1.25 var(--mono)}
.math-gym-modes{display:flex;gap:8px;overflow:auto;padding:2px 0 4px;scrollbar-width:none}.math-gym-modes::-webkit-scrollbar{display:none}.math-gym-modes button{white-space:nowrap;border:1px solid var(--line);background:var(--panel);color:var(--ink);padding:10px 13px;border-radius:999px}.math-gym-modes button.on{background:var(--volt);color:var(--on-volt);border-color:var(--volt);font-weight:700}
.math-gym-start{display:grid;gap:12px}.math-gym-start h2,.math-gym-task h2,.math-gym-dimensions h2,.math-gym-misconceptions h2,.math-gym-skillmap h2{margin:.15rem 0 .35rem}.math-gym-weak-row{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:6px}.math-gym-weak-row>span{color:var(--muted);font:11px/1 var(--mono);text-transform:uppercase;letter-spacing:.06em}
.math-gym-task{display:grid;gap:16px;border-width:2px}.math-gym-task-head{display:flex;justify-content:space-between;gap:18px;align-items:start}.math-gym-round{font:700 12px/1 var(--mono);padding:8px 10px;border-radius:999px;background:var(--bg);border:1px solid var(--line)}.math-gym-prompt{font-size:clamp(19px,2.6vw,28px);line-height:1.28;margin:0;max-width:930px}.math-gym-context{padding:12px 14px;border-left:3px solid var(--volt);background:var(--bg);margin:0;color:var(--muted)}
.math-gym-choice-grid{display:grid;gap:12px}.math-gym-options{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}.math-gym-options.compact{grid-template-columns:repeat(5,minmax(0,1fr))}.math-gym-options button,.math-gym-debug-steps button{min-height:54px;text-align:left;border:1px solid var(--line);background:var(--bg);color:var(--ink);border-radius:13px;padding:12px 14px}.math-gym-options button:hover,.math-gym-debug-steps button:hover{border-color:var(--volt)}.math-gym-options button.on{outline:2px solid var(--volt);outline-offset:1px}.math-gym-options button:disabled,.math-gym-debug-steps button:disabled{opacity:.78}
.math-gym-debug-steps{display:grid;gap:8px;padding-left:0;list-style:none;counter-reset:none}.math-gym-debug-steps li button{width:100%;display:grid;grid-template-columns:74px 1fr;gap:12px;align-items:start}.math-gym-debug-steps span{font:10px/1.3 var(--mono);color:var(--muted);padding-top:3px}.math-gym-debug-steps strong{font-weight:600;line-height:1.4}
.math-gym-worked-steps{display:grid;gap:8px;margin:0;padding-left:24px}.math-gym-worked-steps li{padding:8px 10px;border-radius:10px;background:var(--bg)}.math-gym-worked-steps li.missing{border:1px dashed var(--volt);color:var(--volt);font-weight:700}
.math-gym-estimate{display:grid;gap:14px}.math-gym-estimate-band,.math-gym-exact{display:grid;gap:8px;padding:14px;border-radius:14px;border:1px solid var(--line);background:var(--bg)}.math-gym-exact.locked{opacity:.52}.math-gym-estimate p{margin:0;color:var(--muted)}.math-gym-number-row{display:grid;grid-template-columns:minmax(140px,260px) auto auto;gap:8px;align-items:center}.math-gym-number-row input{min-height:48px;border:1px solid var(--line);border-radius:10px;background:var(--panel);color:var(--ink);padding:10px 12px;font:600 18px/1 var(--mono)}.math-gym-unit{font:12px/1 var(--mono);color:var(--muted)}
.math-gym-resolution{display:grid;gap:9px;padding:16px;border-radius:14px;background:color-mix(in srgb,var(--volt) 8%,var(--bg));border:1px solid color-mix(in srgb,var(--volt) 42%,var(--line))}.math-gym-resolution h3{margin:0}.math-gym-resolution p{margin:0}.math-gym-resolution-meta{display:flex;gap:8px;flex-wrap:wrap}.math-gym-resolution-meta span{font:11px/1 var(--mono);padding:6px 8px;border:1px solid var(--line);border-radius:999px}.math-gym-solution{font-family:var(--mono);color:var(--muted)}.math-gym-diagnosis{display:grid;gap:6px;border-top:1px solid var(--line);padding-top:12px}.math-gym-diagnosis strong{color:var(--hot)}.math-gym-diagnosis .btn{justify-self:start}
.math-gym-dimension-grid{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:8px;margin-top:14px}.math-gym-dimension{display:grid;gap:6px;padding:11px;border-radius:11px;background:var(--bg);border:1px solid var(--line)}.math-gym-dimension span{font:10px/1.2 var(--mono);text-transform:uppercase;color:var(--muted)}.math-gym-dimension strong{font:700 18px/1 var(--display)}.math-gym-dimension .progressbar{height:5px}
.math-gym-mis-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;margin-top:14px}.math-gym-mis-grid article{display:grid;gap:8px;padding:14px;background:var(--bg);border:1px solid var(--line);border-radius:12px}.math-gym-mis-grid p,.math-gym-mis-grid small{margin:0}.math-gym-mis-grid small{color:var(--muted);line-height:1.4}.math-gym-mis-head{display:flex;justify-content:space-between;gap:12px}.math-gym-mis-head span{font:10px/1 var(--mono);color:var(--hot)}
.math-gym-skill-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin-top:14px}.math-gym-skill-grid button{display:grid;grid-template-columns:1fr auto;gap:6px 10px;text-align:left;padding:12px;border:1px solid var(--line);border-radius:12px;background:var(--bg);color:var(--ink)}.math-gym-skill-grid button.on{border-color:var(--volt);box-shadow:inset 0 0 0 1px var(--volt)}.math-gym-skill-grid button>div{display:grid;gap:3px}.math-gym-skill-grid span,.math-gym-skill-grid small{font:10px/1.2 var(--mono);color:var(--muted)}.math-gym-skill-grid>b{font:700 16px/1 var(--display)}.math-gym-skill-grid small{grid-column:1/-1}
@media(max-width:900px){.math-gym-hero{grid-template-columns:1fr}.math-gym-dimension-grid{grid-template-columns:repeat(4,minmax(0,1fr))}.math-gym-skill-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.math-gym-options.compact{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:620px){.math-gym-hero,.math-gym-start,.math-gym-task,.math-gym-dimensions,.math-gym-misconceptions,.math-gym-skillmap{padding:16px;border-radius:14px}.math-gym-metrics{grid-template-columns:1fr 1fr}.math-gym-metrics .math-gym-metric:first-child{grid-column:1/-1}.math-gym-task-head{align-items:center}.math-gym-options,.math-gym-options.compact{grid-template-columns:1fr}.math-gym-dimension-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.math-gym-mis-grid,.math-gym-skill-grid{grid-template-columns:1fr}.math-gym-number-row{grid-template-columns:1fr auto}.math-gym-number-row .btn{grid-column:1/-1}.math-gym-debug-steps li button{grid-template-columns:58px 1fr}}
.math-gym-lookback{display:grid;gap:8px;margin-top:4px;padding-top:12px;border-top:1px solid var(--line)}.math-gym-lookback p{color:var(--muted)}.math-gym-lookback textarea{width:100%;min-height:88px;resize:vertical;border:1px solid var(--line);border-radius:10px;background:var(--panel);color:var(--ink);padding:10px 12px;font:inherit}.math-gym-lookback .btn{justify-self:start}

/* Pass 60 — Math Workbench & Modeling */
.math-workbench-page{display:grid;gap:18px;padding-bottom:44px}.math-workbench-hero,.math-workbench-library,.math-workbench-case-head,.math-workbench-stage{border:1px solid var(--line);background:var(--panel);border-radius:18px;padding:22px}.math-workbench-hero{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:22px;align-items:end;background:linear-gradient(145deg,var(--panel),color-mix(in srgb,var(--volt) 6%,var(--panel)))}.math-workbench-hero h1{max-width:900px;margin:.2rem 0 .6rem}.math-workbench-metrics{display:grid;grid-template-columns:repeat(3,minmax(110px,1fr));gap:8px}.math-workbench-metric{display:grid;gap:2px;min-width:116px;padding:12px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.math-workbench-metric strong{font:700 24px/1 var(--display)}.math-workbench-metric span{font-size:12px}.math-workbench-metric small{font:10px/1.25 var(--mono);color:var(--muted)}
.math-workbench-library{display:grid;gap:14px}.math-workbench-library-head{display:flex;justify-content:space-between;gap:14px;align-items:end}.math-workbench-library-head h2{margin:.2rem 0 0}.math-workbench-case-ribbon{display:flex;gap:9px;overflow:auto;padding:2px 0 6px;scrollbar-width:thin}.math-workbench-case-chip{display:grid;gap:4px;min-width:210px;max-width:240px;text-align:left;padding:11px 12px;border:1px solid var(--line);border-radius:12px;background:var(--bg);color:var(--ink)}.math-workbench-case-chip span,.math-workbench-case-chip small{font:10px/1.2 var(--mono);color:var(--muted)}.math-workbench-case-chip strong{line-height:1.25}.math-workbench-case-chip.on{border-color:var(--volt);box-shadow:inset 0 0 0 1px var(--volt)}.math-workbench-case-chip.done small{color:var(--good)}
.math-workbench-case-head{display:grid;grid-template-columns:minmax(0,1.3fr) minmax(300px,.7fr);gap:22px}.math-workbench-case-head h2{font-size:clamp(26px,4vw,42px);margin:.2rem 0 .6rem}.math-workbench-scenario{font-size:18px;line-height:1.45}.math-workbench-structure-tags{display:flex;flex-wrap:wrap;gap:6px;margin-top:12px}.math-workbench-structure-tags span,.math-workbench-complete-chip{font:10px/1 var(--mono);text-transform:uppercase;letter-spacing:.05em;padding:7px 9px;border-radius:999px;border:1px solid var(--line)}.math-workbench-complete-chip{display:inline-block;margin-top:10px;color:var(--good)}.math-workbench-var-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.math-workbench-var{display:grid;gap:3px;padding:10px;border:1px solid var(--line);border-radius:11px;background:var(--bg)}.math-workbench-var code{color:var(--volt);font-weight:700}.math-workbench-var span,.math-workbench-var small{font-size:11px;color:var(--muted)}
.math-workbench-stage{display:grid;grid-template-columns:54px minmax(0,1fr);gap:18px}.math-workbench-stage-number{display:grid;place-items:center;width:46px;height:46px;border-radius:50%;background:var(--volt);color:var(--on-volt);font:800 20px/1 var(--display)}.math-workbench-stage-body{display:grid;gap:12px;min-width:0}.math-workbench-stage-body h2{margin:.1rem 0 0}.math-workbench-stage-body>p{margin:0}.math-workbench-stage textarea,.math-workbench-stage input[type=text]{width:100%;border:1px solid var(--line);border-radius:11px;background:var(--bg);color:var(--ink);padding:12px;font:inherit}.math-workbench-stage input[type=text]{font-family:var(--mono);font-size:16px;min-height:50px}.math-workbench-stage textarea{min-height:120px;resize:vertical}.math-workbench-frame{min-height:150px!important}.math-workbench-scratch{min-height:170px!important;font-family:var(--mono)!important}.math-workbench-conclusion{min-height:135px!important}
.math-workbench-options,.math-workbench-estimates{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}.math-workbench-estimates{grid-template-columns:repeat(5,minmax(0,1fr))}.math-workbench-options button,.math-workbench-estimates button{min-height:52px;text-align:left;padding:11px 13px;border:1px solid var(--line);border-radius:11px;background:var(--bg);color:var(--ink)}.math-workbench-estimates button{text-align:center}.math-workbench-options button.on,.math-workbench-estimates button.on{border-color:var(--volt);box-shadow:inset 0 0 0 1px var(--volt)}.math-workbench-feedback{grid-column:1/-1;margin:0;padding:10px 12px;border-radius:10px;background:var(--bg)}.math-workbench-feedback.good{color:var(--good)}.math-workbench-feedback.bad{color:var(--hot)}
.math-workbench-model{display:grid;gap:12px}.math-workbench-model label{display:flex;justify-content:space-between;gap:12px;align-items:center}.math-workbench-model label span{font:11px/1 var(--mono);color:var(--muted)}.math-workbench-equation-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px}.math-workbench-model-result{display:grid;gap:4px;padding:12px;border-left:3px solid var(--line);background:var(--bg)}.math-workbench-model-result:empty{display:none}.math-workbench-model-result p{margin:0;color:var(--muted)}.math-workbench-model-result .good{color:var(--good)}.math-workbench-model-result .bad{color:var(--hot)}.math-workbench-scratch-head{display:flex;justify-content:space-between;gap:10px;margin-top:4px}.math-workbench-scratch-head span{font:10px/1.3 var(--mono);color:var(--muted)}.math-workbench-equation-history{display:grid;gap:6px}.math-workbench-equation-history code{padding:8px 10px;border:1px solid var(--line);border-radius:8px;background:var(--bg);overflow:auto}.math-workbench-locked{padding:18px;border:1px dashed var(--line);border-radius:12px;color:var(--muted);font:12px/1.4 var(--mono)}
.math-workbench-verification-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:8px}.math-workbench-verify{display:grid;gap:6px;padding:12px;border:1px solid var(--line);border-radius:11px;background:var(--bg)}.math-workbench-verify>span{font:10px/1 var(--mono);color:var(--muted)}.math-workbench-verify>strong{font:700 18px/1.1 var(--display)}.math-workbench-verify p{margin:0;font-size:12px;color:var(--muted);line-height:1.4}.math-workbench-verify.good>strong{color:var(--good)}.math-workbench-verify.bad>strong{color:var(--hot)}.math-workbench-edge,.math-workbench-badmodel{display:grid;gap:6px;padding:13px 14px;border-radius:12px;background:var(--bg);border:1px solid var(--line)}.math-workbench-edge strong,.math-workbench-badmodel strong{font:10px/1 var(--mono);letter-spacing:.08em}.math-workbench-edge p,.math-workbench-badmodel p{margin:0;color:var(--muted)}.math-workbench-badmodel code{font-size:15px;color:var(--hot)}.math-workbench-ready{font:11px/1.4 var(--mono);color:var(--muted)}
@media(max-width:900px){.math-workbench-hero,.math-workbench-case-head{grid-template-columns:1fr}.math-workbench-verification-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.math-workbench-estimates{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:620px){.math-workbench-hero,.math-workbench-library,.math-workbench-case-head,.math-workbench-stage{padding:16px;border-radius:14px}.math-workbench-metrics{grid-template-columns:1fr 1fr}.math-workbench-metric:first-child{grid-column:1/-1}.math-workbench-library-head{align-items:flex-start;flex-direction:column}.math-workbench-stage{grid-template-columns:1fr}.math-workbench-stage-number{width:38px;height:38px;font-size:17px}.math-workbench-var-grid,.math-workbench-options,.math-workbench-estimates,.math-workbench-verification-grid{grid-template-columns:1fr}.math-workbench-equation-row{grid-template-columns:1fr}.math-workbench-model label,.math-workbench-scratch-head{align-items:flex-start;flex-direction:column}}
.course-math-actions,.profile-action-row{display:flex;gap:8px;flex-wrap:wrap;align-items:center}
.math-workbench-notation{margin:0!important;font:11px/1.45 var(--mono);color:var(--muted)}

/* Pass 61 — expanded modeling corpus, derivation lab, real engineering data lab */
.math-workbench-filter{display:grid;grid-template-columns:minmax(0,1fr) minmax(180px,280px) auto;gap:8px;align-items:center}.math-workbench-filter input,.math-workbench-filter select,.math-data-controls select{min-height:44px;border:1px solid var(--line);border-radius:10px;background:var(--bg);color:var(--ink);padding:9px 11px;font:inherit}.math-workbench-filter-count{font:11px/1 var(--mono);color:var(--muted);white-space:nowrap}.math-workbench-stepcheck{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px;padding:13px;border:1px solid var(--line);border-radius:12px;background:color-mix(in srgb,var(--volt) 4%,var(--bg))}.math-workbench-stepcheck>div:first-child{grid-column:1/-1;display:flex;justify-content:space-between;gap:12px}.math-workbench-stepcheck span{font:10px/1.3 var(--mono);color:var(--muted)}.math-workbench-stepcheck .math-workbench-model-result{grid-column:1/-1}
.math-derive-page,.math-data-page{display:grid;gap:18px;padding-bottom:44px}.math-derive-hero,.math-derive-library,.math-derive-case,.math-derive-builder,.math-derive-boundary,.math-data-hero,.math-data-controls,.math-data-provenance,.math-data-analysis,.math-data-residuals{border:1px solid var(--line);background:var(--panel);border-radius:18px;padding:22px}.math-derive-hero,.math-data-hero{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:22px;align-items:end;background:linear-gradient(145deg,var(--panel),color-mix(in srgb,var(--volt) 6%,var(--panel)))}.math-derive-count,.math-data-metric{display:grid;gap:3px;padding:13px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.math-derive-count strong,.math-data-metric strong{font:700 25px/1 var(--display)}.math-derive-count span,.math-data-metric span{font-size:11px;color:var(--muted)}
.math-derive-library{display:flex;gap:8px;overflow:auto;scrollbar-width:thin}.math-derive-library button{min-width:210px;display:grid;gap:4px;text-align:left;padding:11px;border:1px solid var(--line);border-radius:11px;background:var(--bg);color:var(--ink)}.math-derive-library button.on{border-color:var(--volt);box-shadow:inset 0 0 0 1px var(--volt)}.math-derive-library span,.math-derive-library small{font:10px/1.2 var(--mono);color:var(--muted)}.math-derive-goal{display:flex;gap:12px;align-items:center;margin:14px 0;padding:12px;border-left:3px solid var(--volt);background:var(--bg)}.math-derive-goal strong{font:10px/1 var(--mono)}.math-derive-hints{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px}.math-derive-hints>div{display:grid;gap:5px;padding:11px;border:1px solid var(--line);border-radius:10px;background:var(--bg)}.math-derive-hints b{font:10px/1 var(--mono);color:var(--volt)}.math-derive-hints span{font-size:12px;color:var(--muted);line-height:1.4}.math-derive-step{display:grid;grid-template-columns:42px minmax(0,1fr) auto;gap:10px;align-items:center;margin-top:12px;padding:13px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.math-derive-stepno{display:grid;place-items:center;width:36px;height:36px;border-radius:50%;background:var(--volt);color:var(--on-volt);font-weight:800}.math-derive-step>div:nth-child(2){grid-column:2/-1}.math-derive-step input{grid-column:2/3;width:100%;min-height:46px;border:1px solid var(--line);border-radius:10px;background:var(--panel);color:var(--ink);padding:10px 12px;font:15px var(--mono)}.math-derive-result{grid-column:2/-1;display:grid;gap:4px}.math-derive-result:empty{display:none}.math-derive-result p{margin:0;color:var(--muted)}.math-derive-result .good{color:var(--good)}.math-derive-result .bad{color:var(--hot)}.math-derive-boundary{display:grid;grid-template-columns:1fr 1fr;gap:12px}.math-derive-boundary>div{padding:12px;border:1px solid var(--line);border-radius:10px;background:var(--bg)}.math-derive-boundary strong{font:10px/1 var(--mono)}.math-derive-boundary p{color:var(--muted)}
.math-data-metrics{display:grid;grid-template-columns:repeat(3,minmax(110px,1fr));gap:8px}.math-data-controls{display:grid;grid-template-columns:1.1fr 1fr 1fr auto;gap:10px;align-items:end}.math-data-controls label{display:grid;gap:5px}.math-data-controls label>span{font:10px/1 var(--mono);color:var(--muted)}.math-data-provenance{display:grid;gap:7px}.math-data-provenance p{margin:0;color:var(--muted)}.math-data-meta{display:flex;gap:8px;flex-wrap:wrap}.math-data-meta span{padding:6px 8px;border:1px solid var(--line);border-radius:999px;font:10px/1.2 var(--mono);color:var(--muted)}.math-data-analysis{display:grid;grid-template-columns:minmax(0,1.2fr) minmax(260px,.8fr);gap:16px}.math-data-plot{min-width:0}.math-data-plot svg{width:100%;height:auto;min-height:280px;border:1px solid var(--line);border-radius:12px;background:var(--bg)}.math-data-axis{stroke:var(--muted);stroke-width:1}.math-data-fit{stroke:var(--volt);stroke-width:3}.math-data-point{fill:var(--ink);stroke:var(--panel);stroke-width:2;cursor:pointer}.math-data-point:focus{stroke:var(--volt);stroke-width:4}.math-data-label{fill:var(--muted);font:11px var(--mono)}.math-data-stat-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.math-data-stat{display:grid;gap:3px;padding:10px;border:1px solid var(--line);border-radius:10px;background:var(--bg)}.math-data-stat span,.math-data-stat small{font-size:10px;color:var(--muted)}.math-data-stat strong{font:700 18px/1 var(--display)}.math-data-interpret{grid-column:2;padding:12px;border-left:3px solid var(--volt);background:var(--bg)}.math-data-interpret p{color:var(--muted)}.math-data-table{display:grid;grid-template-columns:70px repeat(4,minmax(0,1fr));overflow:auto}.math-data-table>div{padding:8px;border-bottom:1px solid var(--line);font:12px/1.3 var(--mono)}.math-data-table .head{font-weight:700;color:var(--muted)}.math-data-table .hot{color:var(--hot)}
@media(max-width:900px){.math-workbench-filter,.math-data-controls{grid-template-columns:1fr 1fr}.math-data-analysis{grid-template-columns:1fr}.math-data-interpret{grid-column:1}.math-derive-hero,.math-data-hero{grid-template-columns:1fr}.math-derive-hints{grid-template-columns:1fr}.math-derive-boundary{grid-template-columns:1fr}}
@media(max-width:620px){.math-workbench-filter,.math-data-controls{grid-template-columns:1fr}.math-workbench-stepcheck{grid-template-columns:1fr}.math-workbench-stepcheck>div:first-child{flex-direction:column}.math-derive-hero,.math-derive-library,.math-derive-case,.math-derive-builder,.math-derive-boundary,.math-data-hero,.math-data-controls,.math-data-provenance,.math-data-analysis,.math-data-residuals{padding:16px;border-radius:14px}.math-derive-step{grid-template-columns:34px 1fr}.math-derive-step>div:nth-child(2),.math-derive-step input,.math-derive-result{grid-column:1/-1}.math-data-metrics{grid-template-columns:1fr}.math-data-table{grid-template-columns:55px repeat(4,110px)}}

/* Pass 62 · exceptional math content */
.math-proof-page,.math-cross-page{display:grid;gap:18px;padding-bottom:36px}.math-proof-hero,.math-cross-hero{display:flex;justify-content:space-between;gap:20px;align-items:flex-end;padding:26px;border:2px solid var(--line);background:var(--panel)}.math-proof-count,.math-cross-count{display:grid;min-width:112px;text-align:right}.math-proof-count strong,.math-cross-count strong{font:800 34px/1 var(--mono);color:var(--volt)}.math-proof-library,.math-cross-library{display:flex;gap:10px;overflow-x:auto;padding:4px 0 10px}.math-proof-library button,.math-cross-library button{min-width:210px;text-align:left;border:1px solid var(--line);background:var(--panel);color:var(--ink);padding:12px}.math-proof-library button.on,.math-cross-library button.on{outline:2px solid var(--volt)}.math-proof-library span,.math-cross-library span{display:block;font:700 10px/1.2 var(--mono);text-transform:uppercase;color:var(--muted)}.math-proof-library strong,.math-cross-library strong{display:block;margin-top:6px}.math-proof-scene,.math-cross-case,.math-data-robust,.math-data-missions{border:1px solid var(--line);background:var(--panel);padding:22px}.math-proof-mount svg{width:100%;min-height:300px;border:1px solid var(--line);background:var(--panel)}.math-proof-controls{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin-top:12px}.math-proof-controls label{display:grid;gap:6px;font:700 11px var(--mono)}.math-cross-search input,.math-derive-search{width:100%;padding:13px 14px;border:1px solid var(--line);background:var(--panel);color:var(--ink)}.math-cross-evidence{display:grid;gap:7px;margin:16px 0;padding:14px;border-left:4px solid var(--volt);background:var(--panel-2)}.math-cross-options{display:grid;gap:8px;margin-top:12px}.math-cross-options button{padding:12px;text-align:left;border:1px solid var(--line);background:var(--panel-2);color:var(--ink)}.math-cross-result{margin-top:14px;padding:14px;border-top:1px solid var(--line)}.math-cross-result .good{color:var(--volt)}.math-cross-result .bad{color:var(--danger)}.math-data-robust{margin-top:16px}.math-data-missions details{border-top:1px solid var(--line);padding:10px 0}.math-data-missions summary{cursor:pointer;font-weight:800}.math-derive-search{margin:0 0 12px}@media(max-width:720px){.math-proof-hero,.math-cross-hero{display:grid}.math-proof-count,.math-cross-count{text-align:left}.math-proof-controls{grid-template-columns:1fr}.math-proof-mount svg{min-height:240px}.math-cross-library button,.math-proof-library button{min-width:180px}}

/* Pass 63 · AI systems depth */
.course-ai-systems-shelf,.ai-gym-hero,.rag-bench-hero,.agent-trace-hero,.ai-studio-hero{border:2px solid var(--line);border-radius:18px;padding:18px;background:var(--panel)}
.course-ai-systems-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(210px,1fr));gap:10px;margin:14px 0}
.course-ai-systems-card{display:flex;min-height:92px;flex-direction:column;justify-content:space-between;gap:9px;padding:14px;border:1px solid var(--line);border-radius:14px;background:var(--paper);color:var(--ink);text-decoration:none}
.course-ai-systems-card.is-current{outline:2px solid var(--accent)}
.course-ai-systems-actions,.ai-gym-modes,.ai-studio-nav{display:flex;flex-wrap:wrap;gap:8px}
.ai-gym-page,.rag-bench-page,.agent-trace-page,.ai-studio-page{display:grid;gap:16px;padding-bottom:32px}
.ai-gym-score,.rag-bench-score,.agent-trace-count,.ai-studio-count{font-family:var(--mono);font-weight:700}
.ai-gym-task,.ai-gym-skillmap,.rag-bench-controls,.rag-bench-metrics,.rag-bench-results,.agent-trace-card,.ai-studio-scene{border:1px solid var(--line);border-radius:16px;padding:16px;background:var(--panel)}
.ai-gym-options,.ai-gym-grid{display:grid;gap:8px}.ai-gym-options button,.agent-trace-card button,.ai-studio-nav button{min-height:44px}
.ai-gym-grid{grid-template-columns:repeat(auto-fit,minmax(190px,1fr))}
.rag-bench-controls{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px}.rag-bench-metrics{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:10px}
.rag-bench-results{display:grid;gap:8px}.rag-result{border-left:4px solid var(--accent);padding:10px 12px;background:var(--paper)}
.agent-trace-card{display:grid;gap:10px}.agent-trace-step{min-height:44px;text-align:left}.agent-trace-explain{padding:10px;border-left:4px solid var(--accent);background:var(--paper)}
.ai-studio-scene{display:grid;gap:14px}.ai-studio-mount{min-height:240px;overflow:hidden}.ai-studio-controls{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px}
@media (pointer:coarse){.course-ai-systems-card,.course-ai-systems-actions .btn,.ai-gym-modes button,.ai-studio-nav button{min-height:44px}}

/* Pass 63 · AI Systems Workbench */
.ai-workbench-page{max-width:1120px;margin:0 auto;padding:18px 14px 96px;display:grid;gap:16px}
.ai-workbench-hero{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:end;border:2px solid var(--line);border-radius:18px;padding:20px;background:var(--panel)}
.ai-workbench-hero h1{margin:.2rem 0 .45rem;max-width:760px}.ai-workbench-hero p{max-width:760px;margin:0;color:var(--muted)}
.ai-workbench-count{min-width:132px;border:1px solid var(--line);border-radius:14px;padding:12px;background:var(--paper);display:grid;gap:3px}.ai-workbench-count strong{font-size:1.55rem}.ai-workbench-count span{font-size:.78rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted)}
.ai-workbench-card{border:2px solid var(--line);border-radius:18px;padding:20px;background:var(--paper);display:grid;gap:16px}.ai-workbench-card h2{margin:0}.ai-workbench-scenario{font-size:1.05rem;line-height:1.55;max-width:900px;margin:0}
.ai-workbench-options{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:10px}.ai-workbench-options button{min-height:88px;text-align:left;border:1px solid var(--line);border-radius:14px;padding:13px;background:var(--panel);color:var(--ink);display:grid;gap:6px}.ai-workbench-options button.on{outline:3px solid var(--accent);background:var(--paper)}.ai-workbench-options button strong{font-size:.72rem;letter-spacing:.08em}.ai-workbench-options button span{font-weight:700;line-height:1.35}
.ai-workbench-result{border:2px solid var(--line);border-radius:14px;padding:15px;display:grid;gap:8px}.ai-workbench-result.good{outline:2px solid var(--accent)}.ai-workbench-result.bad{border-style:dashed}.ai-workbench-result p{margin:0}.ai-workbench-result ul{margin:0;padding-left:1.2rem;display:grid;gap:5px}.ai-workbench-nav{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap}
@media(max-width:680px){.ai-workbench-hero{grid-template-columns:1fr}.ai-workbench-count{min-width:0}.ai-workbench-options{grid-template-columns:1fr}}
@media(pointer:coarse){.ai-workbench-options button,.ai-workbench-nav .btn{min-height:44px}}

/* Pass 65 · AI Systems Commissioning & Real-World Cases */
.ai65-page{max-width:1120px;margin:0 auto;padding:18px 14px 96px;display:grid;gap:16px}
.ai65-hero{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:18px;align-items:end;border:2px solid var(--line);border-radius:18px;padding:20px;background:var(--panel)}
.ai65-hero h1{margin:.2rem 0 .45rem;max-width:820px}.ai65-hero p{margin:0;max-width:820px;color:var(--muted)}
.ai65-count{min-width:96px;border:1px solid var(--line);border-radius:14px;padding:12px;background:var(--paper);font-family:var(--mono);font-size:1.25rem;text-align:center}
.ai65-card{border:1px solid var(--line);border-radius:18px;padding:18px;background:var(--paper);display:grid;gap:14px}.ai65-card h2{margin:0}.ai65-lead{font-size:1.04rem;line-height:1.55;margin:0;max-width:900px}
.ai65-block{border-left:4px solid var(--accent);padding:10px 12px;background:var(--panel)}.ai65-block ul{margin:.35rem 0 0;padding-left:1.15rem;display:grid;gap:5px}
.ai65-options{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:10px}.ai65-options button{min-height:72px;text-align:left;border:1px solid var(--line);border-radius:14px;padding:12px;background:var(--panel);color:var(--ink);font-weight:700}.ai65-options button.on{outline:3px solid var(--accent);background:var(--paper)}
.ai65-result{border:2px dashed var(--line);border-radius:14px;padding:14px;display:grid;gap:7px;background:var(--panel)}.ai65-result.good{border-style:solid;outline:2px solid var(--accent)}.ai65-result p{margin:0}.ai65-rollback{border:1px solid var(--line);border-radius:12px;padding:12px;background:var(--panel)}.ai65-rollback p{margin:.3rem 0 0}
.ai65-nav{display:flex;justify-content:space-between;gap:10px;flex-wrap:wrap}.ai65-code{white-space:pre-wrap;overflow:auto;border:1px solid var(--line);border-radius:12px;padding:14px;background:var(--panel);font-family:var(--mono);font-size:.87rem;line-height:1.5}
.ai65-controls{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px}.ai65-controls label{display:grid;gap:7px}.ai65-controls select,.ai65-controls input{min-height:44px}
.ai65-metrics{display:grid;grid-template-columns:repeat(auto-fit,minmax(130px,1fr));gap:10px}.ai65-metrics>div{border:1px solid var(--line);border-radius:14px;padding:12px;background:var(--panel);display:grid;gap:5px}.ai65-metrics span{font-size:.72rem;letter-spacing:.08em;color:var(--muted)}.ai65-metrics strong{font-family:var(--mono);font-size:1.15rem}
.ai65-table{display:grid;gap:7px}.ai65-table>div{display:grid;grid-template-columns:minmax(80px,.6fr) minmax(100px,1fr) minmax(180px,1.5fr) minmax(130px,1fr);gap:8px;align-items:center;border:1px solid var(--line);border-radius:10px;padding:9px;background:var(--panel);font-size:.82rem}.ai65-table>div.severe{outline:2px solid var(--accent)}
@media(max-width:720px){.ai65-hero{grid-template-columns:1fr}.ai65-count{min-width:0}.ai65-options{grid-template-columns:1fr}.ai65-table>div{grid-template-columns:1fr 1fr}.ai65-table>div span:nth-of-type(2){grid-column:1/-1}}
@media(pointer:coarse){.ai65-options button,.ai65-nav .btn,.ai65-controls select,.ai65-controls input{min-height:44px}}

/* Pass 66 · AI Systems Incident Lab & Cross-Stack Commissioning */
.ai66-timeline{display:grid;gap:8px}.ai66-timeline>div{display:grid;grid-template-columns:72px 110px minmax(0,1fr);gap:10px;align-items:start;border-left:4px solid var(--accent);padding:10px 12px;background:var(--panel)}.ai66-timeline b,.ai66-timeline span{font:700 .76rem var(--mono)}.ai66-timeline span{color:var(--muted)}.ai66-timeline p{margin:0;line-height:1.45}.ai66-trace{display:grid;gap:7px}.ai66-trace button{display:grid;grid-template-columns:120px minmax(0,1fr);gap:10px;min-height:52px;text-align:left;border:1px solid var(--line);border-radius:12px;padding:10px 12px;background:var(--panel);color:var(--ink)}.ai66-trace button.on{outline:3px solid var(--accent)}.ai66-trace b{font:700 .72rem var(--mono)}.ai66-regtable{display:grid;gap:6px}.ai66-regtable>div{display:grid;grid-template-columns:1.4fr repeat(3,.7fr);gap:8px;padding:9px 10px;border:1px solid var(--line);border-radius:10px;background:var(--panel);font:600 .82rem var(--mono)}.ai66-regtable>div.head{background:var(--paper);font-size:.72rem;color:var(--muted)}.ai66-regtable>div.critical{outline:2px solid var(--accent)}@media(max-width:680px){.ai66-timeline>div{grid-template-columns:70px 1fr}.ai66-timeline p{grid-column:1/-1}.ai66-trace button{grid-template-columns:1fr}.ai66-regtable>div{grid-template-columns:1.2fr repeat(3,.65fr);font-size:.72rem}}