/* The lesson library (learn-core.js): the public page, the HQ owner library and the in-app Learn screen share this one sheet.
   Mirrored byte for byte at static/learn.css. Every colour comes from the host page's tokens (site.css, hq.css, app.css/classic.css)
   through the aliases below, so the gallery follows Classic light/dark. The hero and the player's readout strip
   are "instruments": always ink with lime light, like hq/charts.css. Cards are windows: an edge, a striped title bar and a hard offset
   shadow, with a small 3D lift on hover. Phone first; no inline styles (CSP), no horizontal overflow. */
.ln,.ln-sheet{
  --l-paper:var(--paper,var(--bg,#e9e7df));--l-win:var(--win,var(--window,var(--card,#f8f7f2)));--l-win2:var(--win-2,var(--chrome,var(--card2,#efede6)));
  --l-ink:var(--text,var(--ink,#17191b));--l-muted:var(--muted,#5f645e);--l-hair:var(--hair,var(--line,rgba(23,25,27,.14)));--l-edge:var(--edge,var(--line,#17191b));
  --l-lime:var(--lime,#b6d82f);--l-lime-ink:var(--lime-ink,#1a2200);--l-r:var(--r,8px);--l-ease:var(--ease,cubic-bezier(.2,.9,.25,1.12));
  --l-display:var(--display,var(--title,"Instrument Serif",Georgia,serif));--l-body:var(--body,"Rokkitt","Arial Narrow",sans-serif);--l-mono:var(--mono,var(--mono,"Cutive Mono",ui-monospace,monospace));
  --p-ink:#0e1210;--p-ink2:#161d18;--p-edge:#2a332c;--p-text:#e7ecdf;--p-muted:rgba(231,236,223,.66);--p-lime:#d7f269;--p-glow:rgba(215,242,105,.45);
  font-family:var(--l-body);color:var(--l-ink);line-height:1.45;-webkit-font-smoothing:antialiased}
.ln *,.ln-sheet *{box-sizing:border-box}
.ln button,.ln-sheet button,.ln input{font:inherit;margin:0}
.ln :focus-visible,.ln-sheet :focus-visible{outline:2px solid var(--l-lime);outline-offset:2px}
.ln-sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.ln-eyebrow{display:block;font-family:var(--l-mono);font-size:12.5px;font-weight:600;letter-spacing:.12em;text-transform:uppercase;margin:0 0 8px}
.ln-led{font-family:var(--l-mono);font-variant-numeric:tabular-nums;letter-spacing:.03em;font-weight:600;color:var(--p-lime);text-shadow:0 0 8px var(--p-glow),0 0 22px rgba(215,242,105,.25)}
.ln-pbar{display:block;height:6px;border-radius:3px;background:rgba(255,255,255,.1);overflow:hidden;border:1px solid rgba(255,255,255,.08)}
.ln-pbar i{display:block;height:100%;width:0;background:var(--p-lime);box-shadow:0 0 10px var(--p-glow);transition:width .4s var(--l-ease)}

/* ---------- hero: an instrument panel ---------- */
.ln-hero{position:relative;isolation:isolate;overflow:hidden;margin:0 0 18px;padding:26px 26px 22px;border:1px solid var(--p-edge);border-radius:14px;color:var(--p-text);
  background:radial-gradient(120% 90% at 0% 0%,var(--p-ink2),var(--p-ink) 62%);box-shadow:inset 0 1px 0 rgba(255,255,255,.07),inset 0 0 0 1px rgba(215,242,105,.06),0 1px 2px -1px rgba(0,0,0,.6),0 24px 50px -30px rgba(0,0,0,.9);
  display:grid;grid-template-columns:minmax(0,1fr);gap:18px}
.ln-hero{container-type:inline-size}
@container (max-width:880px){.ln-hero-art .ln-slab,.ln-hero-art .ln-led-text,.ln-hero-art .ln-ticks{display:none}}/* a narrow hero keeps the globe alone behind the copy */
.ln-hero::after{content:"";position:absolute;inset:0;pointer-events:none;background:repeating-linear-gradient(0deg,rgba(255,255,255,.028) 0 1px,transparent 1px 3px);mix-blend-mode:screen;z-index:2}
.ln-hero-art{position:absolute;inset:0;left:34%;pointer-events:none;z-index:0;-webkit-mask-image:linear-gradient(90deg,transparent,#000 42%);mask-image:linear-gradient(90deg,transparent,#000 42%)}
.ln-hero-art svg{width:100%;height:100%;display:block}
.ln-hero-copy{position:relative;z-index:1;max-width:34rem}
.ln-hero .ln-eyebrow{color:var(--p-lime);text-shadow:0 0 8px var(--p-glow)}
.ln .ln-h1{font-family:var(--l-display);font-size:clamp(28px,4.2vw,44px);font-weight:800;letter-spacing:-.035em;line-height:1.02;margin:0 0 10px;color:#fff;text-wrap:balance;background:none;-webkit-text-fill-color:currentColor}
.ln-lede{margin:0 0 16px;font-size:15.5px;color:var(--p-muted);max-width:30rem}
.ln-search{position:relative;margin:0 0 14px;max-width:30rem}
.ln-search-ico{position:absolute;left:12px;top:50%;transform:translateY(-50%) scaleX(-1);font-size:18px;color:var(--p-lime);pointer-events:none}
.ln .ln-search input{display:block;width:100%;margin:0;padding:11px 12px 11px 36px;border-radius:9px;border:1px solid var(--p-edge);background:rgba(255,255,255,.06);color:#fff;font-size:15px;box-shadow:inset 0 1px 2px rgba(0,0,0,.5);transition:border-color .16s,box-shadow .16s;appearance:none;-webkit-appearance:none}
.ln .ln-search input::placeholder{color:rgba(231,236,223,.5)}
.ln .ln-search input:focus{outline:none;border-color:var(--p-lime);box-shadow:inset 0 1px 2px rgba(0,0,0,.5),0 0 0 3px rgba(215,242,105,.22)}
.ln-progress{display:flex;align-items:center;gap:10px;margin:0;font-size:13px;color:var(--p-muted);flex-wrap:wrap}
.ln-progress .ln-led{font-size:22px;line-height:1}
.ln-progress .ln-pbar{flex:1 1 120px;min-width:90px;max-width:220px}
.ln-mini{display:inline-block;width:30px;height:24px;flex:none}
.ln-mini svg,.ln-none svg{width:100%;height:100%;display:block}
.ln-continue{position:relative;z-index:1;display:flex;align-items:center;gap:14px;padding:10px 12px;border:1px solid var(--p-edge);border-radius:10px;background:rgba(255,255,255,.045);box-shadow:inset 0 1px 0 rgba(255,255,255,.05)}
.ln-continue[hidden]{display:none}
.ln-continue-img{width:112px;aspect-ratio:16/9;object-fit:cover;border-radius:6px;border:1px solid var(--p-edge);background:#000;flex:none}
.ln-continue-body{flex:1;min-width:0;display:grid;gap:4px}
.ln-continue-body .ln-eyebrow{margin:0;color:var(--p-lime)}
.ln-continue-title{font-family:var(--l-display);font-size:16px;letter-spacing:-.01em;color:#fff;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.ln-continue-sub{font-family:var(--l-mono);font-size:12.5px;color:var(--p-muted)}
.ln-continue .ln-pbar{max-width:260px}

/* ---------- art ---------- */
.ln-wire{fill:none;stroke:#d7f269;stroke-opacity:.26;stroke-width:1}
.ln-rim{fill:none;stroke:#d7f269;stroke-opacity:.6;stroke-width:1.2}
.ln-orbit{fill:none;stroke:#d7f269;stroke-opacity:.32;stroke-width:1.2;stroke-dasharray:6 5}
.ln-dot{fill:#d7f269;filter:drop-shadow(0 0 4px #d7f269)}
.ln-sat{transform-origin:0 0;animation:ln-spin 18s linear infinite}
.ln-pings circle{fill:#d7f269;filter:drop-shadow(0 0 3px #d7f269);animation:ln-ping 3.2s ease-in-out infinite}
.ln-pings circle:nth-child(2){animation-delay:.8s}.ln-pings circle:nth-child(3){animation-delay:1.6s}.ln-pings circle:nth-child(4){animation-delay:2.4s}
.ln-sl-front{fill:#d7f269;fill-opacity:.5}.ln-sl-top{fill:#eaff9a;fill-opacity:.9}.ln-sl-side{fill:#93a83a;fill-opacity:.75}
.ln-slab{filter:drop-shadow(0 0 6px rgba(215,242,105,.35))}
.ln-led-text text{font:600 11px var(--l-mono);fill:#d7f269;letter-spacing:.14em}.ln-led-dim{fill-opacity:.6}
.ln-ticks path{fill:none;stroke:#d7f269;stroke-opacity:.35;stroke-width:1}
@keyframes ln-spin{to{transform:rotate(360deg)}}
@keyframes ln-ping{0%,100%{opacity:.25}50%{opacity:1}}

/* ---------- gallery ---------- */
.ln-status{margin:0 0 12px;font-family:var(--l-mono);font-size:12px;letter-spacing:.04em;color:var(--l-muted)}
.ln-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(228px,1fr));gap:18px;padding:0 0 8px}
.ln-grid[hidden]{display:none}
.ln-card{position:relative;margin:0;border:1px solid var(--l-edge);border-radius:var(--l-r);background:var(--l-win);box-shadow:2px 2px 0 var(--l-hair);transition:transform .2s var(--l-ease),box-shadow .2s;will-change:transform;transform-style:preserve-3d}
.ln-card:hover{box-shadow:4px 4px 0 var(--l-edge),0 26px 40px -22px rgba(0,0,0,.55)}
.ln-card:active{transform:translate(1px,1px);box-shadow:1px 1px 0 var(--l-hair)}
.ln-card[hidden]{display:none}
.ln-card-link{display:block;color:inherit;text-decoration:none;border-radius:inherit;height:100%}
.ln-card-link::before{content:"";display:block;height:9px;margin:4px 9px 3px;background:repeating-linear-gradient(180deg,var(--l-edge) 0 1px,transparent 1px 3px);opacity:.5;border-radius:1px}
.ln-poster{position:relative;display:block;aspect-ratio:16/9;overflow:hidden;background:#0e1210;border-top:1px solid var(--l-hair);border-bottom:1px solid var(--l-hair)}
.ln-poster img{width:100%;height:100%;object-fit:cover;display:block;transition:transform .35s var(--l-ease),opacity .2s}
.ln-card:hover .ln-poster img{transform:scale(1.04)}
.ln-dur{position:absolute;right:8px;bottom:8px;font-family:var(--l-mono);font-size:12.5px;font-weight:600;letter-spacing:.04em;color:var(--p-lime);background:rgba(14,18,16,.85);border:1px solid rgba(215,242,105,.35);border-radius:5px;padding:2px 7px;text-shadow:0 0 8px var(--p-glow)}
.ln-tick{position:absolute;left:8px;top:8px;font-family:var(--l-mono);font-size:12.5px;font-weight:600;letter-spacing:.06em;color:var(--l-lime-ink);background:var(--l-lime);border:1px solid rgba(23,25,27,.5);border-radius:5px;padding:2px 7px}
.ln-tick[hidden]{display:none}
.ln-play{position:absolute;left:50%;top:50%;width:46px;height:46px;margin:-23px 0 0 -23px;display:grid;place-items:center;border-radius:50%;background:rgba(14,18,16,.7);border:1px solid rgba(215,242,105,.5);color:var(--p-lime);font-size:18px;padding-left:4px;opacity:0;transform:scale(.8);transition:opacity .2s,transform .2s var(--l-ease);box-shadow:0 0 22px rgba(215,242,105,.3)}
.ln-card:hover .ln-play,.ln-card-link:focus-visible .ln-play{opacity:1;transform:none}
.ln-bar{position:absolute;left:0;right:0;bottom:0;height:3px;background:rgba(255,255,255,.12)}
.ln-bar i{display:block;height:100%;width:0;background:var(--p-lime);box-shadow:0 0 8px var(--p-glow)}
.ln-body{display:grid;gap:4px;padding:10px 12px 12px}
.ln-no{font-family:var(--l-mono);font-size:12.5px;letter-spacing:.14em;color:var(--l-muted)}
.ln-title{font-family:var(--l-display);font-size:15.5px;font-weight:700;letter-spacing:-.015em;line-height:1.2;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.ln-desc{font-size:13px;color:var(--l-muted);line-height:1.4;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.ln-card-meta{font-family:var(--l-mono);font-size:12.5px;letter-spacing:.04em;color:var(--l-muted);margin-top:2px}
.ln-watched .ln-poster img{opacity:.85}
.ln-card:not(.ln-soon) .ln-dur{display:none}/* the poster carries the duration */
.ln-soon .ln-dur{color:var(--p-text);border-color:rgba(255,255,255,.25)}
.ln-none{display:flex;align-items:center;gap:14px;padding:16px;border:1px dashed var(--l-edge);border-radius:var(--l-r);color:var(--l-muted);background:var(--l-win)}
.ln-none[hidden]{display:none}
.ln-none svg{width:64px;height:64px;flex:none;background:var(--p-ink);border-radius:50%;border:1px solid var(--p-edge)}

/* ---------- player sheet ---------- */
.ln-sheet{position:fixed;inset:0;z-index:1200;display:flex;align-items:center;justify-content:center;padding:16px;background:rgba(10,12,10,.6);-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px);animation:ln-fade .18s ease-out}
.ln-panel{width:min(900px,100%);max-height:calc(100vh - 32px);max-height:calc(100dvh - 32px);overflow:auto;overscroll-behavior:contain;background:var(--l-win);color:var(--l-ink);border:1px solid var(--l-edge);border-radius:12px;box-shadow:0 1px 0 rgba(255,255,255,.08) inset,3px 3px 0 var(--l-hair),0 40px 80px -24px rgba(0,0,0,.7);animation:ln-rise .24s var(--l-ease)}
.ln-head{display:flex;align-items:center;gap:10px;height:40px;padding:0 8px 0 12px;border-bottom:1px solid var(--l-edge);background:var(--l-win2);position:sticky;top:0;z-index:2}
.ln-stripes{flex:1;height:12px;background:repeating-linear-gradient(180deg,var(--l-edge) 0 1px,transparent 1px 3px);opacity:.5;border-radius:1px;min-width:12px}
.ln-h2{font-family:var(--l-display);font-size:15px;font-weight:700;letter-spacing:-.01em;margin:0;padding:0 4px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:70%;background:none;-webkit-text-fill-color:currentColor;color:var(--l-ink)}
.ln-x{flex:none;width:30px;height:28px;display:grid;place-items:center;padding:0;border:1px solid var(--l-edge);border-radius:6px;background:var(--l-win);color:var(--l-ink);cursor:pointer;box-shadow:1px 1px 0 var(--l-edge);font-size:13px;line-height:1}
.ln-x:hover{background:var(--l-lime);color:var(--l-lime-ink)}
.ln-x:active{transform:translate(1px,1px);box-shadow:none}
.ln-stage{background:#000}
.ln-stage video{display:block;width:100%;aspect-ratio:16/9;max-height:min(62vh,560px);object-fit:contain;background:#000}
.ln-stage-none{background:var(--p-ink);padding:22px 16px}
.ln-preparing,.ln-err{margin:0;padding:10px 14px;font-size:14px;color:var(--p-text);border-left:4px solid var(--p-lime);background:rgba(215,242,105,.08)}
.ln-err[hidden]{display:none}
.ln-meta{display:flex;align-items:center;gap:12px;flex-wrap:wrap;padding:8px 14px;background:var(--p-ink);color:var(--p-muted);border-top:1px solid var(--p-edge);border-bottom:1px solid var(--l-edge);font-family:var(--l-mono);font-size:12.5px;letter-spacing:.04em;position:relative}
.ln-meta::after{content:"";position:absolute;inset:0;pointer-events:none;background:repeating-linear-gradient(0deg,rgba(255,255,255,.03) 0 1px,transparent 1px 3px)}
.ln-meta .ln-led{font-size:14px}
.ln-right{margin-left:auto}
.ln-chapters{display:flex;flex-wrap:wrap;gap:6px;padding:12px 14px 4px}
.ln-chip{display:inline-flex;align-items:center;gap:7px;padding:6px 10px 6px 6px;border:1px solid var(--l-edge);border-radius:7px;background:var(--l-win);color:var(--l-ink);font-size:13px;font-weight:600;text-align:left;cursor:pointer;box-shadow:1px 1px 0 var(--l-hair);transition:transform .14s var(--l-ease),box-shadow .14s;line-height:1.25}
.ln-chip-n{font-family:var(--l-mono);font-size:12.5px;min-width:20px;height:20px;display:inline-grid;place-items:center;border-radius:5px;background:var(--l-win2);border:1px solid var(--l-hair);color:var(--l-muted)}
.ln-chip:hover{transform:translate(-1px,-1px);box-shadow:2px 2px 0 var(--l-edge)}
.ln-chip.on{background:var(--l-lime);color:var(--l-lime-ink);border-color:var(--l-edge)}
.ln-chip.on .ln-chip-n{background:rgba(23,25,27,.15);color:inherit;border-color:transparent}
.ln-actions{display:flex;flex-wrap:wrap;align-items:center;gap:8px;padding:10px 14px 12px;border-bottom:1px solid var(--l-hair)}
.ln-grow{flex:1}
.ln-btn{display:inline-flex;align-items:center;gap:6px;font-family:var(--l-display);font-weight:700;font-size:14px;padding:9px 14px;border:1px solid var(--l-edge);border-radius:7px;background:var(--l-win);color:var(--l-ink);cursor:pointer;text-decoration:none;box-shadow:2px 2px 0 var(--l-edge);transition:transform .16s var(--l-ease),box-shadow .16s;line-height:1.2;white-space:nowrap}
.ln-btn:hover{transform:translate(-1px,-1px);box-shadow:3px 3px 0 var(--l-edge)}
.ln-btn:active{transform:translate(2px,2px);box-shadow:0 0 0 var(--l-edge)}
.ln-btn.ln-primary,.ln-btn.on{background:var(--l-lime);color:var(--l-lime-ink)}
.ln-btn-app{border-style:dashed}
.ln-transcript{padding:4px 14px 16px}
.ln-sheet details.ln-transcript>summary{cursor:pointer;font-family:var(--l-display);font-weight:700;font-size:14px;padding:8px 0;list-style:none;display:flex;align-items:center;gap:8px;color:var(--l-ink)}
.ln-sheet details.ln-transcript>summary::-webkit-details-marker{display:none}
.ln-sheet details.ln-transcript>summary::before,.ln-sheet details.ln-transcript[open]>summary::before{content:"›";display:inline-block;width:auto;height:auto;margin:0;border:0;background:none;box-shadow:none;animation:none;font-size:18px;line-height:1;transition:transform .2s;color:var(--l-muted)}
.ln-sheet details.ln-transcript[open]>summary::before{transform:rotate(90deg)}
.ln-transcript-body p{margin:0 0 10px;max-width:70ch;font-size:15px;line-height:1.55}
html.ln-open body{overflow:hidden}
@keyframes ln-fade{from{opacity:0}}
@keyframes ln-rise{from{opacity:0;transform:translateY(14px) scale(.985)}}

/* ---------- the public page frame (site/learn/index.html) ---------- */
.ln-main{max-width:1080px;margin:0 auto;padding:18px 16px 60px}
.ln-foot{margin:28px 0 0;font-size:14px;color:var(--l-muted)}
.ln-foot a{color:inherit}

/* ---------- phones (390 wide first) ---------- */
@media (max-width:640px){
  .ln-hero{padding:18px 16px 16px;gap:14px;border-radius:12px}
  .ln-hero-art .ln-slab,.ln-hero-art .ln-led-text,.ln-hero-art .ln-ticks{display:none}
  .ln-hero-art{left:0;opacity:.55;-webkit-mask-image:linear-gradient(180deg,transparent 30%,#000 70%);mask-image:linear-gradient(180deg,transparent 30%,#000 70%)}
  .ln-h1{font-size:28px}.ln-lede{font-size:14.5px}
  .ln-continue{gap:10px;padding:8px 10px;flex-wrap:wrap}
  .ln-continue-img{width:84px}
  .ln-continue-body .ln-eyebrow{font-size:12.5px;letter-spacing:.08em}
  .ln-continue-title{white-space:normal;font-size:15px;line-height:1.2;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical}
  .ln-continue .ln-btn{flex:1 1 100%;justify-content:center}
  .ln-grid{grid-template-columns:repeat(auto-fill,minmax(160px,1fr));gap:12px}
  .ln-body{padding:8px 10px 10px}.ln-title{font-size:14px}.ln-desc{font-size:12.5px}
  .ln-sheet{padding:0;align-items:flex-end}
  .ln-panel{max-height:100vh;max-height:100dvh;border-radius:14px 14px 0 0;border-bottom:0;width:100%}
  .ln-stage video{max-height:52vh}
  .ln-actions .ln-btn{flex:1 1 auto;justify-content:center}
  .ln-main{padding:12px 16px 48px}
}
@media (prefers-reduced-motion:reduce){
  .ln *,.ln *::before,.ln *::after,.ln-sheet,.ln-sheet *{animation:none !important;transition:none !important}
  .ln-card:hover{transform:none}
}
html[data-motion="reduce"] .ln *,html[data-motion="reduce"] .ln-sheet *{animation:none !important;transition:none !important}