:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-2: #f1f5f9;
  --ink: #0f172a;
  --muted: #475569;
  --line: #cbd5e1;
  --accent: #0284c7;
  --accent-soft: #e0f2fe;
  --accent-ink: #0369a1;
  --purple: #7c3aed;
  --purple-soft: #ede9fe;
  --purple-ink: #6d28d9;
  --warn: #d97706;
  --warn-soft: #fef3c7;
  --good: #059669;
  --good-soft: #d1fae5;
  --good-ink: #047857;
  --anom: #dc2626;
  --anom-soft: #fee2e2;
  --chip: #e2e8f0;
  --code-bg: #f1f5f9;
  --on-accent: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 4px 14px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.05);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b1120;
    --surface: #131d31;
    --surface-2: #1e293b;
    --ink: #f1f5f9;
    --muted: #94a3b8;
    --line: #2e3e5c;
    --accent: #38bdf8;
    --accent-soft: #082f49;
    --accent-ink: #7dd3fc;
    --purple: #a78bfa;
    --purple-soft: #2e1065;
    --purple-ink: #c4b5fd;
    --warn: #fbbf24;
    --warn-soft: #451a03;
    --good: #34d399;
    --good-soft: #064e3b;
    --good-ink: #6ee7b7;
    --anom: #f87171;
    --anom-soft: #450a0a;
    --chip: #1e293b;
    --code-bg: #1e293b;
    --on-accent: #0b1120;
    --shadow: 0 1px 3px rgba(0,0,0,0.4), 0 4px 16px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.6), 0 8px 10px -6px rgba(0,0,0,0.4);
  }
}

:root[data-theme="dark"] {
  --bg: #0b1120;
  --surface: #131d31;
  --surface-2: #1e293b;
  --ink: #f1f5f9;
  --muted: #94a3b8;
  --line: #2e3e5c;
  --accent: #38bdf8;
  --accent-soft: #082f49;
  --accent-ink: #7dd3fc;
  --purple: #a78bfa;
  --purple-soft: #2e1065;
  --purple-ink: #c4b5fd;
  --warn: #fbbf24;
  --warn-soft: #451a03;
  --good: #34d399;
  --good-soft: #064e3b;
  --good-ink: #6ee7b7;
  --anom: #f87171;
  --anom-soft: #450a0a;
  --chip: #1e293b;
  --code-bg: #1e293b;
  --on-accent: #0b1120;
  --shadow: 0 1px 3px rgba(0,0,0,0.4), 0 4px 16px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.6), 0 8px 10px -6px rgba(0,0,0,0.4);
}

:root[data-theme="light"] {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-2: #f1f5f9;
  --ink: #0f172a;
  --muted: #475569;
  --line: #cbd5e1;
  --accent: #0284c7;
  --accent-soft: #e0f2fe;
  --accent-ink: #0369a1;
  --purple: #7c3aed;
  --purple-soft: #ede9fe;
  --purple-ink: #6d28d9;
  --warn: #d97706;
  --warn-soft: #fef3c7;
  --good: #059669;
  --good-soft: #d1fae5;
  --good-ink: #047857;
  --anom: #dc2626;
  --anom-soft: #fee2e2;
  --chip: #e2e8f0;
  --code-bg: #f1f5f9;
  --on-accent: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 4px 14px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.05);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 16.5px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent-ink); text-underline-offset: 3px; }
img { max-width: 100%; height: auto; display: block; }
[hidden] { display: none !important; }
.katex { font-size: 1.05em; color: inherit; }
.katex-display { margin: 0.55em 0; overflow-x: auto; overflow-y: hidden; }
.katex-display > .katex { white-space: normal; }

.skip-link {
  position: absolute;
  left: -999px;
  top: 8px;
  background: var(--surface);
  color: var(--ink);
  padding: 8px 12px;
  z-index: 2000;
}
.skip-link:focus { left: 12px; }

#top-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
  padding: 8px 16px;
}
.nav-container {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
}
.nav-brand .badge {
  background: var(--accent);
  color: var(--on-accent);
  padding: 3px 8px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.5px;
}
.nav-pills {
  display: flex;
  align-items: center;
  gap: 3px;
  overflow-x: auto;
  scrollbar-width: none;
  padding: 2px 0;
}
.nav-pills::-webkit-scrollbar { display: none; }
.nav-pill {
  font-size: 12.5px;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
  padding: 4px 8px;
  border-radius: 6px;
  white-space: nowrap;
}
.nav-pill:hover, .nav-pill.active { color: var(--ink); background: var(--surface-2); }
.nav-pill.primer-pill { color: var(--purple); }
.nav-pill.primer-pill:hover, .nav-pill.primer-pill.active { background: var(--purple-soft); }
.theme-switch {
  display: flex;
  flex-shrink: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
}
.theme-opt {
  border: none;
  background: transparent;
  color: var(--muted);
  padding: 6px 12px;
  font-family: inherit;
  font-size: 12.5px;
  font-weight: 700;
  cursor: pointer;
  line-height: 1.2;
}
.theme-opt:hover { color: var(--ink); background: var(--surface-2); }
.theme-opt.on {
  background: var(--accent);
  color: var(--on-accent);
}
.theme-opt.on:hover { background: var(--accent); color: var(--on-accent); }

.main-wrapper { max-width: 1100px; margin: 0 auto; padding: 28px 20px 80px; }

.hero {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 36px 40px;
  margin-bottom: 28px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 5px;
  background: linear-gradient(90deg, var(--accent), var(--purple), var(--good));
}
.hero-kicker {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.8px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}
.hero h1 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  line-height: 1.2;
  margin: 0 0 12px;
  letter-spacing: -0.4px;
}
.hero p { font-size: 18px; color: var(--muted); margin: 0 0 16px; }
.teaching-capsule {
  background: var(--surface-2);
  border: 1px dashed var(--line);
  border-radius: 10px;
  padding: 14px 18px;
  font-size: 15.5px;
}

.q {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 32px 36px;
  margin-bottom: 28px;
  box-shadow: var(--shadow);
  scroll-margin-top: 64px;
}
.qhead { display: flex; align-items: center; gap: 12px; margin-bottom: 8px; flex-wrap: wrap; }
.qn {
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-weight: 800;
  font-size: 13px;
  padding: 4px 10px;
  border-radius: 6px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
}
.qn.primer { background: var(--purple-soft); color: var(--purple-ink); }
.qhead h2 { margin: 0; font-size: 26px; font-weight: 700; letter-spacing: -0.3px; }
.qask { font-size: 17.5px; color: var(--muted); margin: 0 0 16px; }
.q p { margin: 0 0 12px; }
.q ul, .q ol { margin: 0 0 14px; padding-left: 22px; }
.q li { margin-bottom: 6px; }
h3.sub {
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  color: var(--accent);
  margin: 22px 0 10px;
}

.remember {
  background: var(--warn-soft);
  border-left: 4px solid var(--warn);
  border-radius: 0 10px 10px 0;
  padding: 14px 18px;
  margin: 14px 0 18px;
}
.remember .lbl {
  font-size: 12.5px;
  font-weight: 800;
  letter-spacing: 0.6px;
  text-transform: uppercase;
  color: var(--warn);
  margin-bottom: 6px;
}
.remember p { margin: 0 0 8px; }
.remember p:last-child { margin-bottom: 0; }

.note {
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 8px 8px 0;
  padding: 12px 16px;
  margin: 12px 0;
}
.note.purple { border-color: var(--purple); background: var(--purple-soft); }
.note.good { border-color: var(--good); background: var(--good-soft); }
.note.warn { border-color: var(--warn); background: var(--warn-soft); }
.note.anom { border-color: var(--anom); background: var(--anom-soft); }

.flow {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin: 14px 0;
  counter-reset: step;
}
.flow .step {
  position: relative;
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 16px 14px;
}
.flow .step::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  top: -10px;
  left: 12px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--purple);
  color: #fff;
  font-size: 12px;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
}
.flow .step .t { font-weight: 700; margin: 4px 0 8px; }
.flow .step .eq {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 8px;
  margin: 8px 0;
  overflow-x: auto;
  text-align: center;
  min-height: 2.6em;
}
.flow .step .why { color: var(--muted); font-size: 14px; }

.panel {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px 20px;
  margin: 16px 0;
}
.plbl {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
}
button.btn {
  background: var(--surface);
  border: 1px solid var(--line);
  color: var(--ink);
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
}
button.btn:hover { border-color: var(--accent); background: var(--accent-soft); color: var(--accent-ink); }
button.btn.on { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btnrow { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0; }
.slider-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 12px;
  margin: 10px 0;
  min-height: 44px;
}
.slider-row label { color: var(--muted); font-weight: 600; }
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 28px;
  margin: 0;
  padding: 0;
  background: transparent;
  cursor: pointer;
  accent-color: var(--accent);
}
input[type="range"]::-webkit-slider-runnable-track {
  height: 28px;
  border: none;
  border-radius: 999px;
  background: linear-gradient(var(--line), var(--line)) center / 100% 8px no-repeat;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 22px;
  height: 22px;
  margin-top: 3px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--surface);
  box-shadow: 0 1px 4px rgba(0,0,0,.25);
  cursor: pointer;
}
input[type="range"]::-moz-range-track {
  height: 8px;
  border-radius: 999px;
  background: var(--line);
  border: none;
}
input[type="range"]::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--surface);
  cursor: pointer;
}
.fx {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 14px;
  font-weight: 600;
  background: var(--chip);
  padding: 2px 6px;
  border-radius: 4px;
}

.statrow { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; margin: 12px 0; }
.stat {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
  text-align: center;
}
.stat .v {
  display: block;
  font-size: 24px;
  font-weight: 800;
  color: var(--accent-ink);
  font-family: "JetBrains Mono", ui-monospace, monospace;
}
.stat .l { font-size: 12px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.3px; }

.duo { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: start; }
.trio { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 14px; }
.duo.w32 { grid-template-columns: 3fr 2fr; }
.duo.w23 { grid-template-columns: 2fr 3fr; }

.fig {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  overflow: hidden;
}
.fig img { width: 100%; background: #fff; }
.fig .cap {
  padding: 8px 12px;
  margin: 0;
  border-top: 1px solid var(--line);
  background: var(--surface-2);
  color: var(--muted);
  font-size: 14px;
}
.fig.dark img { background: #0b1120; }

.rep-map {
  position: relative;
  line-height: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  overflow: hidden;
}
.rep-map img { width: 100%; height: auto; display: block; }
.rep-overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  pointer-events: none;
}
.rep-overlay .hit { cursor: pointer; pointer-events: auto; outline: none; }
.rep-overlay .hit path,
.rep-overlay .hit ellipse,
.rep-overlay .hit circle {
  fill: rgb(2 132 199 / 0.06);
  stroke: transparent;
  stroke-width: 22;
}
.rep-overlay .hit:hover path,
.rep-overlay .hit:hover ellipse,
.rep-overlay .hit:hover circle,
.rep-overlay .hit.on path,
.rep-overlay .hit.on ellipse,
.rep-overlay .hit.on circle,
.rep-overlay .hit:focus path,
.rep-overlay .hit:focus ellipse,
.rep-overlay .hit:focus circle {
  fill: rgb(2 132 199 / 0.22);
  stroke: var(--accent);
}
.rep-overlay .pin {
  fill: var(--accent);
  stroke: #fff;
  stroke-width: 7;
}
.hit-chips { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 6px; }
.hotspot-card {
  min-height: 12em;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px 14px;
}
.hotspot-card .k { font-size: 12px; font-weight: 800; letter-spacing: 0.4px; text-transform: uppercase; color: var(--accent); }
.diagram-swap { min-height: 260px; background: #fff; }
.diagram-swap img { width: 100%; }
#vae-canvas { width: 100%; height: auto; display: block; border-radius: 8px; background: var(--surface); }

.svgfig { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; padding: 8px; overflow: hidden; max-width: 100%; }
.svgfig svg { width: 100%; max-width: 100%; height: auto; display: block; }
.svgfig text { font-family: Inter, sans-serif; fill: var(--ink); }
.svgfig .muted { fill: var(--muted); }

.arch {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 16px 8px;
  overflow: hidden;
  max-width: 100%;
}
.arch-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
  min-width: 0;
}
.arch-lab {
  flex: 0 0 36px;
  font-weight: 800;
  color: var(--purple-ink);
}
.arch-flow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  min-width: 0;
  flex: 1;
}
.arch-arr { color: var(--muted); font-weight: 700; }
.arch-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  border: 1px solid currentColor;
  text-align: center;
  padding: 6px 8px;
  box-sizing: border-box;
}
.arch-box .arch-t { font-weight: 800; font-size: 13px; line-height: 1.2; }
.arch-box .arch-d { font-size: 11px; color: var(--muted); margin-top: 2px; }
.arch-box.sz-s { min-width: 72px; min-height: 52px; }
.arch-box.sz-m { min-width: 88px; min-height: 60px; }
.arch-box.sz-l { min-width: 100px; min-height: 70px; }
.arch-box.sz-xl { min-width: 112px; min-height: 80px; }
.arch-box.svg-p { background: var(--purple-soft); border-color: var(--purple); color: var(--purple-ink); }
.arch-box.svg-g { background: var(--good-soft); border-color: var(--good); color: var(--good-ink); }
.arch-box.svg-a { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-ink); }
.arch-box.svg-w { background: var(--warn-soft); border-color: var(--warn); color: var(--warn); }

@media (max-width: 620px) {
  .arch-row { flex-direction: column; align-items: stretch; }
  .arch-lab { flex-basis: auto; }
}

.answer { margin-top: 18px; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.answer-toggle {
  width: 100%;
  text-align: left;
  background: var(--surface-2);
  border: none;
  padding: 12px 18px;
  font-family: inherit;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
}
.answer-toggle:hover { background: var(--chip); }
.answer-body { display: none; padding: 16px 20px; border-top: 1px solid var(--line); }
.answer.open .answer-body { display: block; }
.answer.open .chevron { transform: rotate(180deg); }
.chevron { color: var(--muted); transition: transform 0.2s; }

.comp-table { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 15px; }
.comp-table th, .comp-table td { border: 1px solid var(--line); padding: 8px 12px; text-align: left; vertical-align: top; }
.comp-table th { background: var(--surface-2); }
.tbl-wrap { overflow-x: auto; }

code, pre { font-family: "JetBrains Mono", ui-monospace, monospace; font-size: 13.5px; }
pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 14px;
  overflow-x: auto;
  line-height: 1.5;
}
p code, li code, td code { background: var(--chip); padding: 1px 5px; border-radius: 4px; font-size: 13px; }
.small { font-size: 14px; color: var(--muted); }
.pill {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--chip);
  color: var(--muted);
}

.sources { font-size: 14.5px; }
.sources li { margin-bottom: 4px; }

.score-bars { display: grid; gap: 8px; }
.score-row { display: grid; grid-template-columns: 72px 1fr 70px; gap: 8px; align-items: center; font-size: 13px; }
.bar-track { background: var(--chip); height: 14px; border-radius: 4px; overflow: hidden; }
.bar-fill { height: 100%; border-radius: 4px; }
.bar-fill.real { background: var(--good); }
.bar-fill.fake { background: var(--anom); }

.frame-strip { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; }
.frame-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  padding: 0;
  font: inherit;
  color: inherit;
  text-align: left;
}
.frame-card.on { outline: 2px solid var(--accent); }
.frame-card img { width: 100%; background: #111; }
.frame-card .lab { font-size: 12px; padding: 6px 8px; color: var(--muted); }
.gan-cards {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
  margin: 12px 0;
}
.gan-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 8px;
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  text-align: center;
  cursor: pointer;
}
.gan-card:hover { border-color: var(--accent); color: var(--accent-ink); }
.gan-card.on { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-ink); }

.deeper { margin: 14px 0; border: 1px solid var(--line); border-radius: 8px; }
.deeper > summary {
  padding: 12px 16px;
  cursor: pointer;
  font-weight: 600;
  color: var(--muted);
}
.deeper[open] > summary { border-bottom: 1px solid var(--line); color: var(--ink); }
.deeper .detail-body { padding: 14px 16px; }

.hero-figs { display: grid; grid-template-columns: 1.4fr 1fr; gap: 14px; margin: 16px 0 0; align-items: start; }

.story-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin: 18px 0 8px;
}
.story-card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow);
}
a.story-card:hover { border-color: var(--accent); }
.story-card img {
  width: 100%;
  height: 118px;
  object-fit: cover;
  object-position: center 35%;
  background: #0b1120;
}
.story-card .story-k {
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  color: var(--accent-ink);
  padding: 10px 12px 0;
}
.story-card p {
  margin: 4px 0 0;
  padding: 0 12px 14px;
  color: var(--muted);
  font-size: 14.5px;
}
.story-card.static { cursor: default; }

.k-line {
  font-size: 13px;
  font-weight: 700;
  color: var(--purple-ink);
  margin: 0 0 8px;
}

.pipe {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin: 16px 0;
}
.pipe-node {
  background: var(--surface-2);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 14px;
  text-align: center;
  min-width: 76px;
}
.pipe-node.on { background: var(--purple-soft); border-color: var(--purple); }
.pipe-node .pn { display: block; font-weight: 800; line-height: 1.3; }
.pipe-node span:last-child { font-size: 12px; color: var(--muted); }
.pipe-arr {
  color: var(--muted);
  font-weight: 700;
  font-size: 14px;
}

#hourglass {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 8px;
  background: var(--surface);
}

.viz-stage canvas,
#vae-cloud-ae, #vae-cloud-vae, #vae-latent, #vae-decode,
#gan-game, #noise-lab, #bp-viz, #hourglass {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 8px;
  background: var(--surface);
}
#vae-latent { cursor: crosshair; }

.elbo { display: grid; gap: 8px; margin: 14px 0 8px; }
.elbo-row {
  display: grid;
  grid-template-columns: minmax(140px, 220px) 1fr;
  gap: 10px;
  align-items: center;
  font-size: 13px;
  color: var(--muted);
}
.elbo-track { background: var(--chip); height: 12px; border-radius: 999px; overflow: hidden; }
.elbo-fill { height: 100%; border-radius: 999px; width: 40%; transition: width 0.15s linear; }
.elbo-fill.rec { background: var(--accent); }
.elbo-fill.kl { background: var(--purple); }

.svg-p { fill: var(--purple-soft); stroke: var(--purple); }
.svg-g { fill: var(--good-soft); stroke: var(--good); }
.svg-a { fill: var(--accent-soft); stroke: var(--accent); }
.svg-w { fill: var(--warn-soft); stroke: var(--warn); }

@media (max-width: 860px) {
  .duo, .duo.w32, .duo.w23, .trio, .hero-figs, .frame-strip, .story-cards { grid-template-columns: 1fr 1fr; }
  .q { padding: 22px 16px; }
  .hero { padding: 24px 18px; }
}
@media (max-width: 620px) {
  .duo, .duo.w32, .duo.w23, .trio, .hero-figs, .frame-strip, .story-cards { grid-template-columns: 1fr; }
  .elbo-row { grid-template-columns: 1fr; }
  .slider-row { grid-template-columns: 1fr auto; }
  .slider-row label { grid-column: 1 / -1; }
  .gan-cards { grid-template-columns: 1fr 1fr; }
  .theme-opt { padding: 6px 9px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}