/* NumQuest — dark-premium theme (layered near-black + cool undertone). */
:root {
  /* surfaces — flat, warm-tinted near-black (never pure #000/#fff) */
  --bg:#0B0B0C; --bg-2:#161617; --bg-3:#1F1F21; --bg-4:#26262A; --titlebar:#161617;
  --surface-1:#161617; --surface-2:#1F1F21; --surface-3:#26262A;
  --line:#2E2E31; --line-strong:#3A3A3E;
  --ink:#F5F4F2; --ink-strong:#FBFAF9; --ink-soft:#A9A8A4; --ink-faint:#94949A;
  /* accent — amber, the only brand accent (reserved for the next action + rewards, ≤5% of a screen) */
  --accent:#E0A82E; --accent-deep:#C8941F; --accent-soft:#231d10; --accent-ink:#2A1D02;
  /* secondary — muted, warm-leaning; kept only for semantic / category meaning */
  --violet:#a99bf0; --violet-soft:#201d2e;
  --blue:#7FA7C9; --blue-deep:#5E86A8; --blue-soft:#16202a;
  --purple:#b89ad0; --gold:#D9B870; --gold-soft:#262017;
  --green:#5FA77E; --green-soft:#15241c; --orange:#D69A6A; --orange-soft:#26201a;
  --red:#E5614E; --red-soft:#2a1a17;
  --code-bg:#111112; --code-bg-2:#0C0C0D; --code-fg:#E8E6E2;
  /* accent fills + depth — flat fills, single tinted shadow, no colored glow */
  --accent-grad:#E0A82E;
  --accent-grad-soft:var(--accent-soft);
  --glow-accent:0 10px 28px -14px rgba(0,0,0,.7);
  --glow-blue:0 10px 28px -14px rgba(0,0,0,.7);
  --font-display:"Fraunces",Georgia,"Times New Roman",serif;
  --font-body:"Inter",-apple-system,"Segoe UI",system-ui,sans-serif;
  --font-mono:"JetBrains Mono","SF Mono",Consolas,monospace;
  --radius:14px; --radius-sm:10px; --radius-lg:20px; --radius-xs:6px;
  --shadow:0 1px 2px rgba(0,0,0,.5),0 8px 24px -12px rgba(0,0,0,.7);
  --shadow-lift:0 6px 16px rgba(0,0,0,.5),0 24px 56px -20px rgba(0,0,0,.8);
  --shadow-card:0 1px 2px rgba(0,0,0,.45),0 12px 30px -18px rgba(0,0,0,.65);
  --ease:cubic-bezier(.2,.7,.2,1); --ease-spring:cubic-bezier(.34,1.56,.64,1);
}
* { box-sizing:border-box; }
html { height:100%; }
body { margin:0; min-height:100%; color:var(--ink);
  font-family:var(--font-body); font-size:15px; line-height:1.6; -webkit-font-smoothing:antialiased;
  background:var(--bg); }
/* subtle film grain on the page base — atmosphere without the aurora-glow AI tell */
body::before { content:""; position:fixed; inset:0; z-index:0; pointer-events:none; opacity:.035;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E"); }
::selection { background:rgba(224,168,46,.30); color:var(--ink-strong); }
h1,h2,h3,h4 { font-family:var(--font-display); font-weight:600; line-height:1.2; margin:0 0 .4em; color:var(--ink-strong); letter-spacing:-.014em; font-optical-sizing:auto; }
h1 { font-weight:560; letter-spacing:-.022em; }
h2 { font-weight:560; }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration:.001ms !important; animation-iteration-count:1 !important; transition-duration:.001ms !important; }
}
p { margin:.4em 0 .9em; }
button { font-family:inherit; }
/* keyboard focus — visible amber ring, but only for keyboard users (not mouse clicks) */
:focus-visible { outline:2px solid var(--accent); outline-offset:2px; border-radius:3px; }
:focus:not(:focus-visible) { outline:none; }
/* #view is focused programmatically on navigation (for screen readers) — it is not
   an interactive control, so it must not show the keyboard focus ring */
#view:focus, #view:focus-visible { outline:none; }
/* accessibility: screen-reader-only text + skip-to-content link */
.sr-only { position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0; }
.skip-link { position:fixed; top:8px; left:8px; z-index:200; background:var(--accent); color:var(--accent-ink); padding:8px 14px; border-radius:var(--radius-sm); font-weight:600; text-decoration:none; transform:translateY(-160%); transition:transform .15s var(--ease); }
.skip-link:focus { transform:none; outline:2px solid var(--ink-strong); outline-offset:2px; }
/* error + 404 fallback views */
.err-view { max-width:520px; margin:14vh auto 0; text-align:left; }
.err-view .err-eyebrow { font-family:var(--font-mono); font-size:12px; letter-spacing:.12em; text-transform:uppercase; color:var(--accent); margin-bottom:10px; }
.err-view h1 { font-size:32px; }
.err-view .pane-actions { display:flex; gap:10px; margin-top:18px; }
.err-detail { margin-top:22px; }
.err-detail summary { cursor:pointer; color:var(--ink-faint); font-size:13px; }
.err-detail pre { margin-top:8px; padding:12px; background:var(--code-bg); border:1px solid var(--line); border-radius:var(--radius-sm); font-size:12px; color:var(--ink-soft); overflow:auto; white-space:pre-wrap; }
code,pre { font-family:var(--font-mono); }
a { color:var(--accent); }
#app { position:relative; z-index:1; max-width:1180px; margin:0 auto; padding:0 22px 70px; }

/* topbar */
.topbar { position:sticky; top:0; z-index:50; display:flex; align-items:center; justify-content:space-between; padding:12px 14px; margin:0 -14px 8px; border-bottom:1px solid var(--line); background:var(--bg); }
.brand { display:flex; align-items:center; gap:10px; background:none; border:0; cursor:pointer; padding:4px 8px; border-radius:var(--radius-sm); color:var(--ink); }
.brand:hover { background:var(--bg-3); }
.brand-mark { font-size:22px; }
.brand-name { font-family:"Fraunces",serif; font-weight:600; font-size:20px; letter-spacing:-.01em; color:var(--ink-strong); }

/* ---------- Achievements ---------- */
.ach-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(240px,1fr)); gap:10px; margin:14px 0 24px; }
.ach-card { display:flex; gap:14px; align-items:flex-start; padding:14px 16px; border:1px solid var(--line); border-radius:var(--radius); background:var(--surface-1); box-shadow:var(--shadow-card); transition:border-color .15s var(--ease); }
.ach-card.on { border-color:var(--accent); background:var(--accent-soft); }
.ach-card.locked { opacity:.62; }
.ach-card.locked:hover { opacity:.82; }
.ach-ico { flex:0 0 44px; height:44px; display:grid; place-items:center; border-radius:10px; background:var(--bg-3); border:1px solid var(--line); color:var(--ink-soft); }
.ach-card.on .ach-ico { background:var(--accent-soft); border-color:var(--accent); color:var(--accent); }
.ach-meta { min-width:0; flex:1; }
.ach-title { font-weight:600; font-size:14.5px; color:var(--ink-strong); }
.ach-desc { font-size:12.5px; color:var(--ink-soft); margin:2px 0 6px; line-height:1.35; }
.ach-earned { font-family:var(--font-mono); font-size:11px; letter-spacing:.06em; text-transform:uppercase; color:var(--accent); }
.ach-prog { display:flex; align-items:center; gap:8px; }
.ach-prog-bar { flex:1; height:4px; background:var(--bg); border:1px solid var(--line); border-radius:99px; overflow:hidden; }
.ach-prog-bar > i { display:block; height:100%; background:var(--accent); border-radius:99px; }
.ach-prog-num { font-family:var(--font-mono); font-size:11px; color:var(--ink-soft); white-space:nowrap; }
.ach-card.on.tier-gold { border-color:var(--gold); }
.ach-card.on.tier-gold .ach-ico { color:var(--gold); border-color:var(--gold); background:var(--gold-soft); }
@media (max-width:600px){ .ach-grid { grid-template-columns:1fr; } }

/* ---------- Community / forum ---------- */
.forum-filters { display:flex; gap:8px; margin:0 0 12px; flex-wrap:wrap; }
.id-form select, .id-form textarea, .forum-filters select { width:100%; background:var(--bg-2); color:var(--ink); border:1px solid var(--line); border-radius:var(--radius-sm); padding:8px 10px; font-family:var(--font-body); font-size:14px; }
.forum-filters select { width:auto; }
.forum-lab { display:block; font-size:12px; color:var(--ink-soft); margin:12px 0 4px; font-family:var(--font-mono); letter-spacing:.02em; }
.forum-preview { min-height:40px; padding:10px 12px; border:1px dashed var(--line-strong); border-radius:var(--radius-sm); background:var(--bg-2); margin-top:6px; }
.forum-preview:empty::before { content:"live preview…"; color:var(--ink-soft); font-style:italic; }
.forum-opt { display:flex; align-items:center; gap:8px; margin:5px 0; }
.forum-opt input[type=text] { flex:1; }
.forum-check { font-family:var(--font-mono); font-size:12.5px; margin:10px 0 0; min-height:16px; }
.forum-check.ok { color:var(--accent); }
.forum-check.bad { color:var(--red); }
.forum-status { font-family:var(--font-mono); font-size:10.5px; padding:2px 8px; border-radius:99px; border:1px solid var(--line); color:var(--ink-soft); text-transform:uppercase; letter-spacing:.04em; }
.forum-status.published { color:var(--accent); border-color:var(--accent); }
.forum-status.rejected { color:var(--red); border-color:var(--red); }
.forum-status.pending { color:var(--gold); border-color:var(--gold); }
.forum-vote { gap:8px; align-items:center; }
.topbar-stats { display:flex; gap:8px; align-items:center; flex-wrap:wrap; }
.stat-chip { display:inline-flex; align-items:center; gap:6px; background:var(--bg-4); border:1px solid var(--line); border-radius:6px; padding:4px 11px 4px 9px; font-size:12.5px; font-weight:500; color:var(--ink); font-family:var(--font-mono); }
.stat-chip.chip-btn { cursor:pointer; }
.stat-chip.chip-btn:hover { border-color:var(--accent); color:var(--ink-strong); }
.stat-chip .ico { font-size:13px; }
.stat-chip small { font-weight:400; color:var(--ink-soft); font-family:var(--font-body); }
.levelbar { width:60px; height:4px; background:var(--bg); border-radius:99px; overflow:hidden; border:1px solid var(--line); }
.levelbar>i { display:block; height:100%; background:var(--accent); border-radius:99px; transition:width .6s cubic-bezier(.2,.9,.3,1.2); }

.view { animation:viewIn .25s ease both; }
@keyframes viewIn { from { opacity:0; transform:translateY(6px);} to { opacity:1; transform:none;} }

.btn { display:inline-flex; align-items:center; justify-content:center; gap:8px; border-radius:var(--radius-sm); border:1px solid transparent; padding:9px 17px; font-size:13.5px; font-weight:600; cursor:pointer; font-family:var(--font-body); letter-spacing:-.01em; transition:background .16s var(--ease),border-color .16s var(--ease),color .16s var(--ease),box-shadow .18s var(--ease),transform .12s var(--ease); }
.btn:active:not(:disabled) { transform:translateY(1px); }
.btn:disabled { opacity:.4; cursor:not-allowed; transform:none; }
.btn-primary { background:var(--accent); color:var(--accent-ink); border-color:transparent; }
.btn-primary:hover:not(:disabled) { transform:translateY(-1px); background:var(--accent-deep); box-shadow:0 8px 18px -10px rgba(0,0,0,.6); }
.btn-pine { background:var(--blue); color:#05172b; border-color:transparent; }
.btn-pine:hover:not(:disabled) { transform:translateY(-1px); background:var(--blue-deep); box-shadow:0 8px 18px -10px rgba(0,0,0,.6); }
.btn-ghost { background:rgba(255,255,255,.02); color:var(--ink-soft); border-color:var(--line-strong); }
.btn-ghost:hover:not(:disabled) { background:var(--bg-3); color:var(--ink-strong); border-color:var(--line-strong); transform:translateY(-1px); }
.btn-sm { padding:6px 12px; font-size:12.5px; }
.card { background:var(--surface-1); border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow-card); }

/* hero / home */
.hero { padding:34px 0 8px; max-width:780px; }
.hero h1 { font-size:clamp(28px,4.4vw,44px); font-weight:640; font-family:var(--font-display); letter-spacing:-.035em; line-height:1.08; }
.hero h1 em { font-style:normal; color:var(--accent); }
.hero p.lede { font-size:16.5px; color:var(--ink-soft); max-width:62ch; line-height:1.55; }
.hero .resume-row { margin-top:18px; display:flex; gap:10px; flex-wrap:wrap; }
.section-h { margin:26px 0 10px; font-family:var(--font-mono); font-size:13px; letter-spacing:.04em; color:var(--ink-soft); text-transform:uppercase; }

/* knowledge summary band (home) */
.ksum-band { display:flex; gap:10px; align-items:stretch; margin:14px 0 6px; flex-wrap:wrap; }
.ksum { display:flex; flex-direction:column; justify-content:center; gap:1px; padding:12px 18px; min-width:104px; border:1px solid var(--line); border-radius:var(--radius); background:var(--surface-1); box-shadow:var(--shadow-card); }
.ksum b { font-family:var(--font-mono); font-size:26px; font-weight:700; line-height:1.05; color:var(--ink-strong); }
.ksum span { font-size:11.5px; color:var(--ink-soft); letter-spacing:.01em; }
.ksum-green b { color:var(--accent); }
.ksum-yellow b { color:var(--gold); }
.ksum-blue b { color:var(--blue); }
.ksum-map { margin-left:auto; align-self:center; }

/* today card */
.today-card { padding:16px 18px; margin:18px 0 6px; }
.today-head .kick { font-family:var(--font-mono); font-size:11px; letter-spacing:.08em; color:var(--accent); }
.today-rows { display:grid; gap:10px; margin-top:10px; }
.today-row { display:flex; align-items:center; gap:12px; padding:10px 12px; border:1px solid var(--line); border-radius:var(--radius-sm); background:var(--bg-3); }
.today-row.hot { border-color:var(--orange); background:var(--orange-soft); }
.today-row b { font-family:var(--font-mono); font-size:20px; color:var(--accent); min-width:1.5em; text-align:center; }
.today-row.hot b { color:var(--orange); }
.today-row span { color:var(--ink); flex:1; }
.today-row .muted, .muted { color:var(--ink-faint); font-style:italic; }

/* trail / chapter cards */
.trail { display:grid; gap:9px; }
.chapter-card { display:flex; gap:16px; align-items:center; width:100%; text-align:left; cursor:pointer; padding:15px 18px; background:var(--surface-1); border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow-card); transition:transform .18s var(--ease),border-color .18s var(--ease),box-shadow .18s var(--ease),background .18s var(--ease); color:var(--ink); }
.chapter-card:hover:not(.locked) { border-color:var(--line-strong); transform:translateY(-2px); box-shadow:0 10px 24px -14px rgba(0,0,0,.7); }
.chapter-card.locked { opacity:.55; }
.chapter-card .ch-icon { flex:0 0 42px; height:42px; display:grid; place-items:center; font-size:22px; background:var(--bg-3); border-radius:8px; border:1px solid var(--line); }
.chapter-card.current .ch-icon { background:var(--blue-soft); border-color:var(--blue); }
.chapter-card.done .ch-icon { background:var(--accent-soft); border-color:var(--accent); }
.chapter-card .ch-body { flex:1; min-width:0; }
.chapter-card .ch-kicker { font-family:var(--font-mono); font-size:11px; letter-spacing:.06em; color:var(--ink-faint); text-transform:uppercase; }
.chapter-card h3 { font-size:16px; margin:1px 0 2px; font-family:var(--font-body); }
.chapter-card .ch-desc { color:var(--ink-soft); font-size:13px; margin:0; }
.ch-progress { flex:0 0 auto; text-align:right; font-size:12px; color:var(--ink-soft); font-family:var(--font-mono); }
.ring { width:40px; height:40px; }
.ring circle { fill:none; stroke-width:4; }
.ring .ring-bg { stroke:var(--bg-3); }
.ring .ring-fg { stroke:var(--accent); stroke-linecap:round; transition:stroke-dashoffset .6s ease; }

/* crumb / chapter head */
.crumb { display:flex; gap:8px; margin:16px 0 6px; font-size:13px; font-family:var(--font-mono); }
.crumb button { background:none; border:0; color:var(--blue); cursor:pointer; font-size:13px; font-family:var(--font-mono); }
.crumb button:hover { text-decoration:underline; }
.chapter-head { display:flex; align-items:center; gap:16px; margin:8px 0 22px; }
.chapter-head .big-icon { font-size:38px; }
.chapter-head h1 { font-size:26px; margin:0; }
.chapter-head .ch-desc { color:var(--ink-soft); margin:2px 0 0; }

/* lessons */
.lesson-list { display:grid; gap:8px; max-width:820px; }
.lesson-row { display:flex; align-items:center; gap:14px; width:100%; text-align:left; background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius); padding:12px 16px; cursor:pointer; transition:transform .16s var(--ease),background .16s var(--ease),border-color .16s var(--ease),box-shadow .16s var(--ease); color:var(--ink); }
.lesson-row:hover:not(.locked) { background:var(--bg-3); border-color:var(--accent); transform:translateX(2px); box-shadow:var(--shadow-card); }
.lesson-row.locked { opacity:.55; }
.lesson-row .ls-num { flex:0 0 28px; height:28px; display:grid; place-items:center; border-radius:6px; background:var(--bg-3); font-weight:600; font-size:12.5px; color:var(--ink-soft); font-family:var(--font-mono); border:1px solid var(--line); }
.lesson-row.done .ls-num { background:var(--accent); color:#0f1f1c; border-color:var(--accent); }
.lesson-row.current .ls-num { background:var(--blue); color:#0f1a26; border-color:var(--blue); }
.lesson-row h4 { margin:0; font-size:14.5px; font-weight:500; }
.lesson-row .ls-meta { margin-left:auto; color:var(--ink-faint); font-size:11.5px; white-space:nowrap; font-family:var(--font-mono); }

/* player */
.player-top { display:flex; align-items:center; gap:16px; margin:12px 0; }
.player-top h2 { font-size:17px; margin:0; flex:1; min-width:0; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.stepdots { display:flex; gap:5px; }
.stepdots i { width:7px; height:7px; border-radius:2px; background:var(--line-strong); transition:all .2s; }
.stepdots i.done { background:var(--accent); }
.stepdots i.now { background:var(--blue); width:18px; }
.learn-pane { padding:20px 22px; background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius); max-width:100%; overflow-x:hidden; }
.learn-pane h3 { font-size:18px; }
.step-kicker { font-family:var(--font-mono); font-size:11px; letter-spacing:.08em; color:var(--accent); margin-bottom:4px; }
.md { font-size:14.5px; color:var(--ink); }
.md code { background:var(--bg-4); border:1px solid var(--line); border-radius:4px; padding:1px 6px; font-size:.9em; color:var(--orange); }
.md pre { background:var(--code-bg-2); color:var(--code-fg); border-radius:var(--radius-sm); border:1px solid var(--line); padding:12px 14px; overflow-x:auto; font-size:13px; }
.md pre code { background:none; border:0; padding:0; }
.md ul { padding-left:22px; } .md li { margin:4px 0; }
.md strong { color:var(--ink-strong); }
.md .callout { border-left:3px solid var(--blue); background:var(--blue-soft); border-radius:0 var(--radius-sm) var(--radius-sm) 0; padding:10px 14px; margin:12px 0; }
.math-display { display:block; margin:10px 0; max-width:100%; overflow-x:auto; overflow-y:hidden; }
/* Contain wide display equations (long PDEs): the inner KaTeX block has
   white-space:nowrap, so IT must be the scroll container, not just the wrapper. */
.math-display .katex-display { overflow-x:auto; overflow-y:hidden; padding-bottom:4px; margin:0; }
.math-display .katex-display > .katex { text-align:initial; } /* fits → centered; long → starts left, visible */
.math-error { color:var(--red); font-family:var(--font-mono); }
.pane-actions { display:flex; gap:8px; margin-top:16px; flex-wrap:wrap; align-items:center; }

/* quiz */
.quizbox { padding:4px 0; }
.quizbox .q-prompt { font-size:15px; font-weight:600; margin-bottom:4px; color:var(--ink-strong); }
.q-options { display:grid; gap:7px; margin-top:12px; }
.q-opt { text-align:left; padding:10px 14px; border-radius:var(--radius-sm); border:1px solid var(--line-strong); background:var(--bg-3); font-size:14px; cursor:pointer; transition:all .12s; color:var(--ink); }
.q-opt:hover:not(:disabled) { border-color:var(--blue); background:var(--blue-soft); }
.q-opt.picked-right { border-color:var(--green); background:var(--green-soft); color:var(--ink-strong); }
.q-opt.picked-wrong { border-color:var(--red); background:var(--red-soft); }
.q-opt:disabled { cursor:default; }
.q-fill { display:flex; gap:10px; margin-top:12px; }
.q-fill input { flex:1; padding:9px 13px; border-radius:var(--radius-sm); border:1px solid var(--line-strong); font-size:15px; font-family:var(--font-mono); background:var(--code-bg); color:var(--ink); }
.q-fill input:focus { outline:1px solid var(--accent); border-color:var(--accent); }
.q-fill input.ok { border-color:var(--accent); }
.q-explain { margin-top:12px; border-radius:var(--radius-sm); padding:10px 13px; font-size:13.5px; border:1px solid var(--line); animation:viewIn .25s ease both; }
.q-explain.right { background:var(--green-soft); color:#b8d6a8; border-color:var(--green); }
.q-explain.wrong { background:var(--orange-soft); color:#e8c0a8; border-color:var(--orange); }
.q-explain.revealed { background:var(--blue-soft); color:#bcd; border-color:var(--blue); }
.q-explain .why { display:block; margin-top:4px; opacity:.95; }
.q-explain .q-note { display:block; margin-top:7px; padding-top:6px; border-top:1px dashed var(--line); color:#d9b873; font-size:12.5px; }
.q-explain, .quizbox .q-prompt { max-width:100%; overflow-x:auto; overflow-y:hidden; }
.q-postactions { display:flex; gap:8px; margin-top:8px; flex-wrap:wrap; }
.q-review-note { margin-top:8px; font-size:12.5px; color:var(--orange); }
.result-strip { font-family:var(--font-mono); font-size:11.5px; opacity:.85; margin-top:6px; }

/* roadmap */
.roadmap-pick input { width:100%; padding:9px 13px; margin:6px 0 14px; border-radius:var(--radius-sm); border:1px solid var(--line-strong); background:var(--code-bg); color:var(--ink); font-size:14px; }
.roadmap-picklist { display:flex; flex-direction:column; gap:4px; max-height:60vh; overflow-y:auto; }
.rm-pick-row { padding:8px 12px; border:1px solid var(--line); border-radius:var(--radius-sm); background:var(--bg-2); cursor:pointer; font-size:13.5px; color:var(--ink); }
.rm-pick-row:hover { border-color:var(--accent); background:var(--bg-3); }
.rm-pick-ch { background:var(--bg-3); }
.rm-pick-l { margin-left:16px; color:var(--ink-soft); }
.roadmap-list { display:flex; flex-direction:column; gap:6px; }
.roadmap-step { display:flex; gap:10px; align-items:center; padding:9px 12px; border:1px solid var(--line); border-radius:var(--radius-sm); background:var(--bg-2); cursor:pointer; transition:background .12s,border-color .12s; }
.roadmap-step:hover { border-color:var(--line-strong); background:var(--bg-3); }
.roadmap-step.done { opacity:.6; }
.roadmap-step.next { border-color:var(--blue); background:var(--blue-soft); }
.roadmap-step .rm-ico { width:20px; text-align:center; }
.roadmap-step .rm-title { flex:1; font-size:14px; color:var(--ink); }
.roadmap-step .rm-go { font-family:var(--font-mono); font-size:11.5px; color:var(--accent); }
.roadmap-step .rm-go.muted { color:var(--ink-faint); }
.roadmap-chdiv { font-family:var(--font-mono); font-size:11px; letter-spacing:.06em; color:var(--accent); margin:12px 0 2px; }

/* onboarding */
.onboarding h1 { margin-bottom:6px; }
.onb-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(180px,1fr)); gap:10px; margin:16px 0; }
.onb-grid.onb-modes { grid-template-columns:repeat(auto-fit,minmax(260px,1fr)); }
.onb-card { display:flex; flex-direction:column; gap:3px; text-align:left; padding:14px 16px; border:1px solid var(--line-strong); border-radius:var(--radius); background:var(--bg-2); cursor:pointer; color:var(--ink); transition:border-color .12s,background .12s; }
.onb-card:hover { border-color:var(--accent); background:var(--bg-3); }
.onb-card.sel { border-color:var(--accent); background:var(--accent-soft); }
.onb-card b { font-size:15px; color:var(--ink-strong); }
.onb-card span { font-size:12.5px; color:var(--ink-soft); }

/* settings preferences */
.pref-grid { grid-template-columns:repeat(auto-fit,minmax(240px,1fr)); }
.pref-card { padding:14px 16px; }
.pref-title { font-weight:600; color:var(--ink-strong); margin-bottom:8px; }
.pref-modes { display:flex; flex-wrap:wrap; gap:8px; margin-bottom:8px; }
.pref-modes .btn { flex:1 1 64px; }
.lvl-badge { font-family:var(--font-mono); font-size:9.5px; letter-spacing:.04em; color:var(--orange); border:1px solid var(--orange); border-radius:4px; padding:1px 5px; margin-left:6px; vertical-align:middle; }

/* chapter assessment ("checkup") result list */
.assess-weaklist { display:flex; flex-direction:column; gap:8px; margin:10px 0; }
.assess-weak { display:flex; justify-content:space-between; align-items:center; gap:10px; width:100%; text-align:left; padding:10px 14px; border:1px solid var(--orange); border-radius:var(--radius-sm); background:var(--bg-2); color:var(--ink); cursor:pointer; transition:background .12s,border-color .12s; }
.assess-weak:hover { background:var(--bg-3); border-color:var(--orange); }
.assess-weak span:first-child { font-size:14px; }

/* leaderboard */
.lb-tabs { display:flex; gap:6px; margin:8px 0 14px; background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius); padding:5px; }
.lb-tabs button { flex:1; background:none; border:0; color:var(--ink-soft); cursor:pointer; padding:9px 10px; border-radius:var(--radius-sm); font-family:var(--font-body); font-weight:600; font-size:13.5px; transition:background .15s var(--ease),color .15s var(--ease); }
.lb-tabs button:hover { color:var(--ink-strong); }
.lb-tabs button.on { background:var(--accent); color:var(--accent-ink); }
.lb-league-banner { display:flex; align-items:center; gap:14px; padding:14px 16px; border:1px solid var(--line); border-radius:var(--radius); background:var(--accent-soft); margin-bottom:12px; }
.lb-league-banner .lb-league-ico { font-size:30px; }
.lb-league-banner b { display:block; color:var(--ink-strong); font-size:16px; }
.lb-list { display:flex; flex-direction:column; gap:5px; }
.lb-row { display:grid; grid-template-columns:42px 1fr auto auto; align-items:center; gap:12px; padding:11px 15px; border:1px solid var(--line); border-radius:var(--radius-sm); background:var(--bg-2); transition:border-color .15s var(--ease); }
.lb-row:hover { border-color:var(--line-strong); }
.lb-row.me { border-color:var(--accent); background:color-mix(in srgb,var(--accent) 7%,var(--bg-2)); }
/* "You could be here" aspirational slot — glowing amber, draws the eye. */
.lb-aspire { border:1.5px dashed var(--accent); background:var(--accent-soft); animation:aspirePulse 2.2s ease-in-out infinite; }
.lb-aspire .lb-rank, .lb-aspire .lb-xp { color:var(--accent); }
.lb-aspire .lb-name { color:var(--accent); font-weight:600; }
.lb-aspire-cta { justify-content:center; margin-top:14px; }
@keyframes aspirePulse { 0%,100% { box-shadow:0 0 0 0 rgba(224,168,46,0); } 50% { box-shadow:0 0 0 3px rgba(224,168,46,.18); } }
@media (prefers-reduced-motion: reduce) { .lb-aspire { animation:none; } }
.lb-rank { font-family:var(--font-mono); font-weight:700; font-size:15px; color:var(--ink-soft); text-align:center; }
.lb-rank-top { font-size:16px; }
.lb-rank-top.r1 { color:var(--gold); }
.lb-rank-top.r2 { color:var(--ink); }
.lb-rank-top.r3 { color:var(--orange); }
.lb-name { color:var(--ink-strong); font-weight:600; font-size:14.5px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.lb-flag { font-size:14px; }
.lb-youtag { font-family:var(--font-mono); font-size:10px; color:var(--accent); border:1px solid var(--accent); border-radius:4px; padding:0 5px; margin-left:4px; vertical-align:middle; }
.lb-lvl { font-family:var(--font-mono); font-size:12px; color:var(--ink-faint); }
.lb-xp { font-family:var(--font-mono); font-size:13px; color:var(--accent); font-weight:600; }
.lb-gate { padding:20px 22px; text-align:center; }
.lb-gate p { color:var(--ink-soft); }
/* Public Premium badge — amber star + PRO, shown next to names and in the topbar. */
.pro-badge { display:inline-flex; align-items:center; gap:3px; font-family:var(--font-mono); font-size:9.5px; font-weight:700; letter-spacing:.04em; color:var(--accent); background:var(--accent-soft); border:1px solid var(--accent-deep); border-radius:4px; padding:0 4px; margin-left:5px; vertical-align:middle; line-height:1.6; }
.pro-badge svg { width:11px; height:11px; }
.stat-chip.pro-chip { color:var(--accent); border-color:var(--accent-deep); background:var(--accent-soft); font-weight:700; letter-spacing:.03em; }
.stat-chip.pro-cta { color:var(--accent); }
.stat-chip.pro-cta:hover { border-color:var(--accent); background:var(--accent-soft); }
/* Premium upgrade screen (#/premium + feature-gate upsell) — editorial, asymmetric. */
.prem { max-width:980px; margin:0 auto; padding:8px 4px 40px; }
.prem-grid { display:grid; grid-template-columns:1fr 320px; gap:56px; align-items:start; }
.prem-kicker { display:inline-block; font-family:var(--font-mono); font-size:12px; letter-spacing:.14em; text-transform:uppercase; color:var(--accent); margin-bottom:16px; }
.prem-locked { display:inline-block; margin:0 0 14px; padding:5px 11px; border:1px solid var(--line); border-left:2px solid var(--accent); border-radius:4px; background:var(--bg-4); color:var(--ink-soft); font-size:13px; }
.prem-locked b { color:var(--ink-strong); font-weight:600; }
.prem-title { font-family:var(--font-display); font-size:clamp(34px,5vw,52px); line-height:1.05; letter-spacing:-.02em; margin:0 0 18px; max-width:13ch; }
.prem-lede { font-size:16.5px; line-height:1.62; color:var(--ink-soft); max-width:46ch; margin:0 0 38px; }
.prem-amber { color:var(--accent); font-weight:600; white-space:nowrap; }
.prem-feats { display:grid; gap:0; }
.prem-feat { padding:18px 0; border-top:1px solid var(--line); }
.prem-feat:last-child { border-bottom:1px solid var(--line); }
.prem-feat h3 { font-family:var(--font-display); font-size:18px; font-weight:600; margin:0 0 4px; color:var(--ink-strong); }
.prem-feat p { margin:0; font-size:14px; line-height:1.55; color:var(--ink-soft); max-width:52ch; }
/* the buy card — the one place amber is allowed to carry weight */
.prem-buy { position:sticky; top:18px; border:1px solid var(--line); border-radius:12px; background:var(--surface); padding:26px 24px; }
.prem-price { display:flex; align-items:baseline; gap:7px; margin-bottom:18px; }
.prem-amt { font-family:var(--font-display); font-size:42px; font-weight:600; color:var(--ink-strong); letter-spacing:-.02em; }
.prem-per { font-family:var(--font-mono); font-size:14px; color:var(--ink-faint); }
.prem-cta { width:100%; justify-content:center; font-size:15px; padding:12px 18px; }
.prem-renew { margin:10px 2px 0; font-size:11.5px; line-height:1.5; color:var(--ink-faint); text-align:center; }
.prem-assure { list-style:none; padding:0; margin:18px 0 0; display:grid; gap:10px; }
.prem-assure li { position:relative; padding-left:22px; font-size:13px; color:var(--ink-soft); }
.prem-assure li::before { content:"✓"; position:absolute; left:0; color:var(--accent); font-weight:700; }
.prem-have-view { max-width:760px; }
.prem-have-view .prem-feats { margin-top:8px; }
.prem-foot { margin-top:28px; }
@media (max-width:760px) {
  .prem-grid { grid-template-columns:1fr; gap:34px; }
  .prem-buy { position:static; }
  .prem-lede { margin-bottom:28px; }
}
.id-form { display:grid; gap:14px; margin:14px 0; }
.id-form label { display:flex; flex-direction:column; gap:6px; font-size:13px; color:var(--ink-soft); }
.id-form input, .id-form select { background:var(--bg-3); border:1px solid var(--line-strong); color:var(--ink); padding:10px 12px; border-radius:var(--radius-sm); font-family:var(--font-body); font-size:14.5px; }
.id-form input:focus, .id-form select:focus { outline:none; border-color:var(--accent); }
@media (max-width:560px) { .lb-row { grid-template-columns:34px 1fr auto; } .lb-row .lb-lvl { display:none; } }

/* admin dashboard */
.adm-bars { display:flex; flex-direction:column; gap:7px; margin:10px 0 4px; }
.adm-bar-row { display:grid; grid-template-columns:150px 1fr 42px; align-items:center; gap:12px; }
.adm-bar-lab { font-size:13px; color:var(--ink-soft); white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
.adm-bar-track { height:10px; background:var(--bg-3); border-radius:999px; overflow:hidden; border:1px solid var(--line); }
.adm-bar-track > i { display:block; height:100%; background:var(--accent); border-radius:999px; transition:width .5s var(--ease); }
.adm-bar-val { font-family:var(--font-mono); font-size:12.5px; color:var(--ink); text-align:right; }
.adm-spark { display:flex; align-items:flex-end; gap:5px; height:96px; padding:8px 4px 0; border:1px solid var(--line); border-radius:var(--radius); background:var(--bg-2); margin:8px 0; }
.adm-spark-col { flex:1; display:flex; flex-direction:column; align-items:center; justify-content:flex-end; height:100%; gap:5px; }
.adm-spark-col > i { width:70%; min-height:2px; background:var(--accent); border-radius:4px 4px 0 0; transition:height .5s var(--ease); }
.adm-spark-col > span { font-family:var(--font-mono); font-size:9px; color:var(--ink-faint); }
@media (max-width:560px) { .adm-bar-row { grid-template-columns:110px 1fr 32px; } .adm-spark-col > span { display:none; } }
/* Admin ROI / net panel — revenue minus the admin-entered monthly cost. */
.adm-roi { display:flex; flex-wrap:wrap; align-items:center; justify-content:space-between; gap:18px; padding:16px 18px; margin:10px 0 4px; }
.adm-roi-input { display:flex; flex-direction:column; gap:6px; font-size:13px; color:var(--ink-soft); }
.adm-roi-input input { width:170px; padding:8px 10px; background:var(--bg-4); border:1px solid var(--line); border-radius:6px; color:var(--ink); font-family:var(--font-mono); font-size:14px; }
.adm-roi-input input:focus { outline:none; border-color:var(--accent); }
.adm-roi-out { display:flex; gap:30px; }
.adm-roi-out > div { display:flex; flex-direction:column; gap:3px; }
.adm-roi-out b { font-family:var(--font-display); font-size:23px; line-height:1; }
.adm-pos { color:var(--accent); }
.adm-neg { color:#d9786a; }
/* Admin moderation — user management list. */
.adm-search { width:100%; max-width:340px; padding:9px 12px; margin:6px 0 12px; background:var(--bg-4); border:1px solid var(--line); border-radius:7px; color:var(--ink); font-family:var(--font-body); font-size:14px; }
.adm-search:focus { outline:none; border-color:var(--accent); }
.adm-users { display:flex; flex-direction:column; gap:6px; }
.adm-user { display:grid; grid-template-columns:1fr auto auto; align-items:center; gap:14px; padding:9px 14px; border:1px solid var(--line); border-radius:var(--radius-sm); background:var(--bg-2); }
.adm-user.banned { opacity:.55; }
.adm-user-name { font-weight:500; display:flex; align-items:center; gap:6px; flex-wrap:wrap; }
.adm-user-meta { font-family:var(--font-mono); font-size:12px; color:var(--ink-faint); white-space:nowrap; }
.adm-user-actions { display:flex; gap:6px; align-items:center; }
.adm-tag { font-family:var(--font-mono); font-size:9px; letter-spacing:.05em; text-transform:uppercase; padding:1px 5px; border-radius:4px; }
.tag-admin { color:var(--accent); border:1px solid var(--accent-deep); }
.tag-mod { color:var(--blue); border:1px solid var(--blue-deep); }
.tag-ban { color:#d9786a; border:1px solid #d9786a; }
.adm-ban-btn:hover { border-color:#d9786a !important; color:#d9786a !important; }
@media (max-width:560px){ .adm-user { grid-template-columns:1fr; gap:6px; } }

/* proof-order */
.proof-order { margin-top:12px; }
.proof-slot { list-style:decimal; padding-left:26px; margin:0 0 10px; display:grid; gap:6px; min-height:8px; }
.proof-slot.ok .proof-step { border-color:var(--green); background:var(--green-soft); }
.proof-step { background:var(--bg-3); border:1px solid var(--line-strong); border-radius:var(--radius-sm); padding:8px 12px; cursor:pointer; }
.proof-bank { display:flex; flex-direction:column; gap:6px; margin-bottom:10px; }
.proof-chip { text-align:left; background:var(--bg-4); border:1px dashed var(--line-strong); border-radius:var(--radius-sm); padding:8px 12px; cursor:pointer; color:var(--ink); }
.proof-chip:hover { border-color:var(--blue); }

/* coach */
.coach { border-radius:var(--radius); padding:14px 16px 12px; border:1px solid var(--line); display:flex; gap:12px; margin-top:12px; background:var(--bg-2); animation:viewIn .25s ease both; }
.coach .coach-ico { font-size:22px; }
.coach h5 { margin:0 0 3px; font-size:14px; color:var(--ink-strong); }
.coach p { margin:0 0 4px; font-size:13.5px; }
.coach.coach-warn { background:var(--orange-soft); border-color:var(--orange); color:#e8c0a8; }
.coach.coach-warn h5 { color:var(--orange); }
.coach.coach-err { background:var(--red-soft); border-color:var(--red); color:#f4c0b3; }
.coach.coach-ok { background:var(--green-soft); border-color:var(--green); color:#b8d6a8; }

/* modal / celebrate / toast */
.modal-scrim { position:fixed; inset:0; background:rgba(0,0,0,.7); display:grid; place-items:center; z-index:60; padding:20px; animation:fadeIn .2s ease both; }
@keyframes fadeIn { from { opacity:0; } }
.modal { background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius); box-shadow:var(--shadow-lift); max-width:580px; width:100%; max-height:86vh; overflow:auto; padding:24px 26px; animation:popIn .3s cubic-bezier(.2,.9,.3,1.15) both; }
@keyframes popIn { from { opacity:0; transform:scale(.95) translateY(8px); } }
.modal .modal-kicker { font-family:var(--font-mono); font-size:11px; letter-spacing:.1em; color:var(--accent); }
.modal h2 { font-size:22px; margin:4px 0 10px; }
.modal .modal-actions { display:flex; gap:10px; justify-content:flex-end; margin-top:18px; flex-wrap:wrap; }
.celebrate { text-align:center; }
.celebrate .big { font-size:56px; margin:6px 0; animation:bounceIn .5s cubic-bezier(.2,.9,.3,1.4) both; }
@keyframes bounceIn { from { transform:scale(.3); opacity:0; } 60% { transform:scale(1.15); } }
.celebrate .xp-gain { font-family:var(--font-mono); font-weight:700; font-size:26px; color:var(--accent); }
.celebrate .sub { color:var(--ink-soft); }
#toastRoot { position:fixed; right:22px; bottom:22px; display:flex; flex-direction:column; gap:8px; z-index:70; }
.toast { background:var(--bg-2); border:1px solid var(--line-strong); color:var(--ink); border-radius:var(--radius-sm); padding:9px 16px; font-size:13.5px; box-shadow:var(--shadow-lift); font-family:var(--font-mono); animation:toastIn .35s cubic-bezier(.2,.9,.3,1.2) both; }
.toast.gold { border-color:var(--gold); color:var(--gold); }
@keyframes toastIn { from { opacity:0; transform:translateY(10px) scale(.96); } }
.toast.bye { animation:toastOut .25s ease both; }
@keyframes toastOut { to { opacity:0; transform:translateY(6px); } }

/* visuals + plotter */
.visual-box { background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius); padding:14px 16px; margin:14px 0; }
.visual-box .vis-title { font-family:var(--font-mono); font-size:11px; letter-spacing:.07em; color:var(--ink-faint); margin-bottom:8px; }
.vis-controls { display:flex; gap:14px; margin-top:12px; flex-wrap:wrap; align-items:center; }
.vis-note { font-size:13px; color:var(--ink-soft); margin-top:8px; min-height:1.3em; font-family:var(--font-mono); }
.vis-slider { display:flex; align-items:center; gap:8px; font-size:13px; color:var(--ink-soft); font-family:var(--font-mono); }
.vis-slider input[type=range] { accent-color:var(--accent); }
.plot-canvas { width:100%; height:auto; display:block; background:var(--code-bg-2); border-radius:var(--radius-sm); border:1px solid var(--line); }
.plot-grid { stroke:var(--line); stroke-width:1; opacity:.5; }
.plot-axis { stroke:var(--line-strong); stroke-width:1.4; }
.plot-canvas text { font-family:var(--font-mono); fill:var(--ink-soft); font-size:11px; }

/* knowledge map + walls */
.map-legend { display:flex; gap:8px; margin:6px 0 14px; flex-wrap:wrap; }
.map-legend .gnode { cursor:default; opacity:.85; }
.map-branch { margin:14px 0; }
.map-branch h4 { font-size:14px; margin:0 0 8px; }
.map-branch h4 small { color:var(--ink-faint); font-family:var(--font-mono); font-size:10.5px; letter-spacing:.06em; text-transform:uppercase; margin-left:6px; }
.map-grid { display:flex; flex-wrap:wrap; gap:8px; }
.chapter-card.hot { border-color:var(--orange); }
.chip-hot { color:var(--orange); font-family:var(--font-mono); font-size:10px; letter-spacing:.04em; }
.lesson-row.hot { border-color:var(--orange); }
.lesson-row.hot .ls-num { background:var(--orange-soft); color:var(--orange); border-color:var(--orange); }
.lesson-row small.muted { display:block; font-size:11px; color:var(--orange); font-style:normal; font-family:var(--font-mono); }
.placement-count { color:var(--ink-faint); font-family:var(--font-mono); font-size:12px; }

/* Step-5 systems: speed / olympiad / ambush */
.chapter-siblings { display:flex; gap:8px; margin:-10px 0 16px; flex-wrap:wrap; }
.banner-warn { background:var(--orange-soft); border:1px solid var(--orange); color:#e8c0a8; padding:9px 14px; border-radius:var(--radius-sm); font-size:13px; margin:8px 0 12px; font-family:var(--font-mono); }
.speed-modes { display:grid; gap:10px; grid-template-columns:repeat(auto-fill, minmax(220px, 1fr)); margin:14px 0; }
.speed-mode { padding:14px 16px; text-align:left; cursor:pointer; line-height:1.5; transition:border-color .12s, transform .12s; }
.speed-mode:hover { border-color:var(--accent); transform:translateY(-1px); }
.speed-mode b { color:var(--ink-strong); font-size:14px; }
.speed-mode small { color:var(--ink-soft); font-size:12px; }
.speed-box { background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius); padding:16px; margin:14px 0; }
.speed-status { font-family:var(--font-mono); font-size:12.5px; color:var(--ink-soft); margin-bottom:8px; }
.speed-timer { height:4px; background:var(--accent); border-radius:99px; transition:width .1s linear; margin-bottom:14px; }
.speed-qhost .quizbox { padding:0; }

/* Settings page */
.settings-grid { display:grid; grid-template-columns:repeat(auto-fill, minmax(160px, 1fr)); gap:10px; margin:14px 0 20px; }
.stat-card { padding:14px 16px; text-align:left; }
.stat-num { font-family:var(--font-display); font-size:28px; color:var(--ink-strong); line-height:1.1; }
.stat-lab { font-size:11.5px; color:var(--ink-soft); margin-top:4px; }
.btn-danger { background:#5a2a2a; color:#e8c0a8; border-color:#7a3a3a; }
.btn-danger:hover { background:#6a3a3a; border-color:var(--red); }
.btn.danger { color:var(--red); }
.muted.small, .vis-note.muted { color:var(--ink-faint); font-size:12px; }
.schema-status { background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius-sm); padding:10px 12px; font-family:var(--font-mono); font-size:12px; color:var(--ink-soft); white-space:pre-wrap; }

/* SVG icons — line-art glyphs replacing emoji clip-art */
.ico-svg { display:inline-block; vertical-align:-2px; }
.ch-icon .ico-svg { vertical-align:-4px; }
.big .ico-svg { vertical-align:middle; opacity:.85; }
.h-ico { display:inline-flex; vertical-align:-3px; margin-right:6px; color:var(--accent); }
.branch-ico { display:inline-flex; vertical-align:-3px; margin-right:4px; }
.stat-chip .ico { display:inline-flex; align-items:center; }
.lesson-row .ls-num .ico-svg { vertical-align:-2px; }
.ico-svg text { fill:currentColor; stroke:none; }
.gnode { border:1px solid var(--line-strong); border-radius:999px; padding:6px 13px; font-size:12.5px; font-family:var(--font-mono); cursor:pointer; color:var(--ink); background:var(--bg-3); transition:transform .14s var(--ease),border-color .14s var(--ease),box-shadow .14s var(--ease),background .14s var(--ease); }
.gnode:hover { transform:translateY(-1px); border-color:var(--accent); box-shadow:0 6px 16px -8px rgba(0,0,0,.6); }
.gnode.g-green { background:var(--accent-soft); border-color:var(--accent); color:var(--accent); }
.gnode.g-yellow { background:var(--gold-soft); border-color:var(--gold); color:var(--gold); }
.gnode.g-blue { background:var(--blue-soft); border-color:var(--blue); color:var(--blue); }
.gnode.g-gray { background:var(--bg-3); border-color:var(--line); color:var(--ink-faint); }
.gnode--justmastered { animation:gnodePulse 1.1s var(--ease-spring) both; }
@keyframes gnodePulse {
  0% { box-shadow:0 0 0 0 rgba(224,168,46,.55); transform:scale(1); }
  40% { box-shadow:0 0 0 8px rgba(224,168,46,0); transform:scale(1.12); }
  100% { box-shadow:0 0 0 0 rgba(224,168,46,0); transform:scale(1); }
}
/* staggered card/list entrance */
@keyframes riseIn { from { opacity:0; transform:translateY(10px); } to { opacity:1; transform:none; } }
.trail .chapter-card, .lesson-list .lesson-row { animation:riseIn .4s var(--ease) both; }

/* "Where am I" dashboard */
.wa-table { display:flex; flex-direction:column; gap:2px; margin:8px 0 18px; }
.wa-row { display:grid; grid-template-columns:2fr 2fr 1fr 1fr; align-items:center; gap:10px; padding:8px 12px; background:var(--bg-2); border:1px solid var(--line); border-radius:var(--radius-sm); font-size:13px; }
.wa-row.wa-row3 { grid-template-columns:2fr 2fr 1fr; }
.wa-row.wa-row2 { grid-template-columns:1fr 2fr; }
.wa-row.wa-head { background:transparent; border:none; color:var(--ink-faint); font-size:11.5px; text-transform:uppercase; letter-spacing:.04em; padding:2px 12px; }
.wa-ch { display:flex; align-items:center; gap:8px; color:var(--ink); font-weight:500; }
.wa-ico { color:var(--ink-faint); display:inline-flex; }
.wa-bar { display:inline-block; width:90px; max-width:55%; height:7px; background:var(--bg-3); border-radius:999px; overflow:hidden; vertical-align:middle; }
.wa-bar-fill { display:block; height:100%; background:var(--accent); border-radius:999px; }
.wa-chips { display:flex; flex-wrap:wrap; gap:7px; margin:6px 0 18px; }
.wa-chip { border:1px solid var(--line-strong); border-radius:999px; padding:5px 12px; font-size:12px; font-family:var(--font-mono); cursor:pointer; color:var(--ink); background:var(--bg-3); }
.wa-chip:hover { border-color:var(--accent); color:var(--accent); }
.wall-path { display:flex; flex-wrap:wrap; gap:6px; align-items:center; margin:10px 0; }
.wall-path .arrow { color:var(--ink-faint); }
.empty-note { color:var(--ink-soft); font-style:italic; padding:24px; text-align:center; }

.schema-report { background:var(--red-soft); border:1px solid var(--red); color:#f4c0b3; border-radius:var(--radius-sm); padding:11px 14px; margin:12px 0; font-size:13px; white-space:pre-wrap; font-family:var(--font-mono); }

/* lesson "passed" state — between fresh and mastered (mastery check cleared, awaiting spaced review) */
.lesson-row.passed { border-color:var(--accent); background:linear-gradient(90deg, var(--bg-2), color-mix(in srgb, var(--accent) 6%, var(--bg-2))); }
.lesson-row.passed .ls-num { background:color-mix(in srgb, var(--accent) 35%, var(--bg-3)); color:var(--accent); border-color:var(--accent); }
.lesson-row.passed h4 { color:var(--ink); }
.lesson-row.passed small.muted { color:var(--accent); font-family:var(--font-mono); }

/* chapter header strip — passed/mastered counts + next-up pointer */
.chapter-strip { display:flex; flex-wrap:wrap; gap:8px; margin:8px 0 14px; font-family:var(--font-mono); font-size:12px; }
.strip-chip { background:var(--bg-2); border:1px solid var(--line); padding:5px 10px; border-radius:999px; color:var(--ink-soft); }
.strip-chip.strip-gold { background:color-mix(in srgb, var(--gold, var(--accent)) 10%, var(--bg-2)); border-color:var(--gold, var(--accent)); color:var(--gold, var(--accent)); }
.strip-chip.strip-next { background:color-mix(in srgb, var(--blue) 10%, var(--bg-2)); border-color:var(--blue); color:var(--blue); }
.strip-chip b { color:inherit; font-weight:600; }

/* lesson-row actions area: quick "practice more" + meta */
.lesson-row .ls-actions { display:flex; align-items:center; gap:8px; margin-left:auto; }
.lesson-row .ls-drill { background:transparent; border:1px solid var(--line); color:var(--ink-soft); width:26px; height:26px; border-radius:6px; cursor:pointer; display:grid; place-items:center; }
.lesson-row .ls-drill:hover { border-color:var(--blue); color:var(--blue); }

/* completion modal "Next →" line */
.celebrate .next-line { color:var(--blue); font-family:var(--font-mono); font-size:13px; margin-top:6px; }

/* home page: stack resume + next-up chips on the same row */
.resume-chips { display:inline-flex; gap:8px; flex-wrap:wrap; margin-left:auto; }

/* account & cloud sync panel */
.auth-card p { margin:6px 0; }
.sync-badge { display:inline-block; font-family:var(--font-mono); font-size:11px; font-weight:600; color:var(--accent); background:var(--accent-soft); border:1px solid var(--accent); border-radius:999px; padding:2px 9px; margin-right:6px; vertical-align:middle; }
.auth-form { display:flex; gap:8px; align-items:center; margin:8px 0; flex-wrap:wrap; }
.auth-form input { flex:1 1 220px; background:var(--bg-3); border:1px solid var(--line); color:var(--ink); padding:9px 12px; border-radius:var(--radius-sm); font-family:var(--font-mono); font-size:13px; }
.auth-form input:focus { outline:none; border-color:var(--blue); }
.auth-card code { background:var(--bg-3); padding:1px 5px; border-radius:3px; font-size:11.5px; }

/* math symbol palette (Desmos-style) — small button beside answer inputs */
.q-fill { position:relative; }
.sym-trigger { background:var(--bg-3); border:1px solid var(--line); color:var(--ink-soft); width:34px; height:34px; display:grid; place-items:center; border-radius:var(--radius-sm); cursor:pointer; transition:border-color .12s,color .12s; }
.sym-trigger:hover { border-color:var(--blue); color:var(--blue); }
.sym-trigger-glyph { font-family:var(--font-mono); font-size:18px; line-height:1; font-weight:600; }
.sym-palette { position:absolute; z-index:60; right:0; top:100%; margin-top:6px; background:var(--bg-2); border:1px solid var(--line-strong); border-radius:var(--radius); padding:10px 12px 8px; box-shadow:0 12px 32px rgba(0,0,0,.45); max-width:min(560px, 95vw); }
.sym-group { margin-bottom:8px; }
.sym-grouplabel { font-family:var(--font-mono); font-size:10.5px; color:var(--ink-faint); text-transform:uppercase; letter-spacing:.08em; margin:0 0 4px; }
.sym-grid { display:flex; flex-wrap:wrap; gap:4px; }
.sym-chip { background:var(--bg-3); border:1px solid var(--line); color:var(--ink); min-width:30px; height:30px; padding:0 8px; border-radius:6px; cursor:pointer; font-family:var(--font-mono); font-size:15px; line-height:1; transition:background .12s,border-color .12s,color .12s; }
.sym-chip:hover { background:var(--bg); border-color:var(--blue); color:var(--blue); }
.sym-close { background:transparent; border:none; color:var(--ink-faint); font-size:11px; font-family:var(--font-mono); cursor:pointer; padding:4px 6px; margin-top:4px; }
.sym-close:hover { color:var(--ink); }
@media (max-width:620px) { .sym-palette { right:auto; left:0; max-width:calc(100vw - 24px); } }
#confettiCanvas { position:fixed; inset:0; pointer-events:none; z-index:80; }

* { scrollbar-width:thin; scrollbar-color:var(--line-strong) transparent; }
*::-webkit-scrollbar { width:10px; height:10px; }
*::-webkit-scrollbar-thumb { background:var(--line-strong); border-radius:5px; border:2px solid var(--bg); }

/* mobile bottom navigation (hidden on desktop) */
.mobnav { display:none; }

/* ---------- responsive ---------- */
@media (max-width:980px) {
  .settings-grid { grid-template-columns:repeat(auto-fill,minmax(140px,1fr)); }
}
@media (max-width:760px) {
  #app { padding:0 14px 84px; }
  .chapter-card { gap:12px; padding:13px 14px; }
  .chapter-card .ch-desc { display:none; }
  .pane-actions, .chapter-siblings { gap:6px; }
  .modal { padding:20px 18px; }
  .ksum-map { margin-left:0; flex-basis:100%; }
  .player-top h2 { font-size:15.5px; }
}
@media (max-width:620px) {
  .hero { padding:22px 0 6px; }
  .hero h1 { font-size:clamp(24px,7vw,31px); }
  .hero p.lede { font-size:15px; }
  .topbar-stats .stat-chip small { display:none; }
  .topbar-stats .stat-chip { padding:4px 8px; }
  .topbar-stats .levelbar { display:none; }
  .topbar-stats #settingsChip { display:none; }  /* settings is in the bottom nav on mobile */
  .btn { padding:10px 16px; }
  .btn-sm { padding:8px 12px; }
  .mobnav { display:flex; position:fixed; left:0; right:0; bottom:0; z-index:55;
    background:var(--bg);
    border-top:1px solid var(--line); padding:6px 6px max(6px,env(safe-area-inset-bottom)); }
  .mobnav-item { flex:1; display:flex; flex-direction:column; align-items:center; gap:2px; background:none; border:0;
    color:var(--ink-faint); cursor:pointer; padding:6px 0; border-radius:10px; font-size:10px; font-weight:600; font-family:var(--font-body); transition:color .14s var(--ease); }
  .mobnav-item .mobnav-ico { display:inline-flex; }
  .mobnav-item.on { color:var(--accent); }
  .wa-row, .wa-row.wa-row3, .wa-row.wa-row2 { grid-template-columns:1fr auto; }
}
@media (max-width:430px) {
  .settings-grid { grid-template-columns:1fr 1fr; }
  .ksum { min-width:0; flex:1; padding:10px; }
  .ksum-band { gap:6px; }
}