:root {
  --bg: #0a0e13;
  --surface: #121921;
  --surface-2: #18212b;
  --border: #243140;
  --text: #e8eef4;
  --muted: #8d9bab;
  --warm: #ffb454;
  --cool: #4cc3ff;
  --radius: 14px;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

a { color: var(--warm); }
h1, h2, h3 { line-height: 1.2; margin: 0 0 0.5em; }
h2 { font-size: 1.2rem; }
h3 { font-size: 1rem; }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--muted); }
.small { font-size: 0.85rem; }

.wrap { max-width: 1240px; margin: 0 auto; padding: 0 16px; }

.masthead {
  padding: 48px 0 32px;
  background:
    radial-gradient(900px 300px at 15% -10%, rgba(255, 180, 84, 0.14), transparent 70%),
    radial-gradient(700px 260px at 85% 0%, rgba(76, 195, 255, 0.10), transparent 70%);
  border-bottom: 1px solid var(--border);
  margin-bottom: 28px;
}
.eyebrow {
  margin: 0 0 8px;
  color: var(--warm);
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.site-nav { display: flex; gap: 8px; flex-wrap: wrap; margin-bottom: 24px; }
.site-nav a {
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 99px;
  color: var(--muted);
  font-size: 0.85rem;
  text-decoration: none;
}
.site-nav a:hover { color: var(--text); }
.site-nav a[aria-current="page"] { color: var(--text); border-color: var(--warm); }
.masthead h1 { font-size: clamp(2rem, 5vw, 3.2rem); letter-spacing: -0.02em; }
.lede { max-width: 640px; color: #c4cfda; font-size: 1.08rem; margin: 0 0 20px; }
.facts { display: flex; flex-wrap: wrap; gap: 10px 24px; list-style: none; margin: 0; padding: 0; color: var(--muted); }
.facts strong { color: var(--text); font-family: var(--mono); font-weight: 600; margin-right: 4px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.stage {
  display: grid;
  grid-template-columns: minmax(280px, 380px) 1fr;
  gap: 20px;
  margin-bottom: 20px;
}

label { display: block; font-size: 0.9rem; margin-bottom: 12px; color: #c4cfda; }
input, textarea, select {
  display: block;
  width: 100%;
  margin-top: 4px;
  padding: 9px 11px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
}
textarea { resize: vertical; }
input:focus, textarea:focus, select:focus, button:focus-visible, a:focus-visible {
  outline: 2px solid var(--warm);
  outline-offset: 1px;
}
.options { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

button, .button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 14px;
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  font: inherit;
  font-size: 0.9rem;
  text-decoration: none;
  cursor: pointer;
}
button:hover:not(:disabled), .button:hover { border-color: #3a4b5e; }
button:disabled { opacity: 0.5; cursor: default; }
button.primary {
  width: 100%;
  padding: 12px;
  background: var(--warm);
  color: #1d1305;
  border: none;
  font-weight: 650;
  font-size: 1rem;
}
.examples { display: flex; flex-wrap: wrap; gap: 6px; align-items: center; margin-bottom: 14px; font-size: 0.85rem; }
.examples button { padding: 4px 10px; font-size: 0.8rem; border-radius: 99px; }
.privacy { font-size: 0.8rem; color: var(--muted); margin: 12px 0 0; }

.views { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
figure { margin: 0; }
figure canvas {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  background: var(--bg);
  border-radius: 10px;
  border: 1px solid var(--border);
}
figcaption { font-size: 0.8rem; color: var(--muted); margin-top: 6px; text-align: center; }

.transport { display: flex; align-items: center; gap: 10px; margin-top: 16px; flex-wrap: wrap; }
.rate, .seg { display: inline-flex; }
.rate button, .seg button { border-radius: 0; padding: 8px 10px; }
.rate button:first-child, .seg button:first-child { border-radius: 8px 0 0 8px; }
.rate button:last-child, .seg button:last-child { border-radius: 0 8px 8px 0; }
.rate button + button, .seg button + button { border-left: none; }
.rate button.on, .seg button[aria-pressed="true"] { background: #2a3746; color: var(--warm); }
#play-btn { width: 40px; padding: 8px 0; }
.progress { flex: 1; min-width: 80px; height: 6px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
#progress-bar { width: 0; height: 100%; background: var(--warm); }
#clock { font-size: 0.85rem; color: var(--muted); min-width: 56px; text-align: right; }
.status { font-size: 0.85rem; color: var(--muted); margin: 10px 0 0; min-height: 1.4em; }

.meter { margin-top: 18px; padding-top: 14px; border-top: 1px solid var(--border); }
.meter-label { display: block; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin-bottom: 8px; }
.meter-row { display: flex; align-items: center; gap: 10px; font-size: 0.8rem; color: #c4cfda; }
.meter-track { position: relative; flex: 1; height: 14px; background: var(--surface-2); border-radius: 99px; overflow: hidden; }
.meter-track::after { content: ""; position: absolute; left: 50%; top: 0; bottom: 0; width: 2px; margin-left: -1px; background: var(--border); }
#meter-fill { position: absolute; top: 0; bottom: 0; left: 50%; width: 0; background: var(--warm); border-radius: 99px; }
.meter p { margin: 8px 0 0; }

.reply-card { margin-bottom: 20px; border-color: rgba(255, 180, 84, 0.45); }
.reply-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 8px; }
.reply-head h2 { margin: 0; }
.reply-actions { display: flex; gap: 8px; }
#reply-text {
  white-space: pre-wrap;
  font: 0.92rem/1.6 var(--mono);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  margin: 0 0 10px;
  overflow-wrap: anywhere;
}

.brain { margin-bottom: 20px; }
.brain-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 20px; flex-wrap: wrap; margin-bottom: 14px; }
.brain-head p { max-width: 640px; margin: 0; font-size: 0.9rem; }
.legend { width: 260px; font-size: 0.75rem; color: var(--muted); }
.colorbar {
  height: 10px;
  border-radius: 99px;
  background: linear-gradient(90deg, #d4f0ff, #2fa8ff 20%, #222c38 50%, #ff9d3d 80%, #fff1c2);
}
.legend-labels { display: flex; justify-content: space-between; margin: 4px 0 8px; }
.gain { display: flex; align-items: center; gap: 8px; font-size: 0.75rem; margin: 0; }
.gain input { margin: 0; padding: 0; border: none; background: none; accent-color: var(--warm); }

.brain-body { display: grid; grid-template-columns: 1fr 320px; gap: 20px; align-items: start; }
.group { margin-bottom: 18px; }
.group h3 { font-size: 0.95rem; margin-bottom: 2px; }
.group > p { font-size: 0.82rem; color: var(--muted); margin: 0 0 8px; }
.panels { display: grid; grid-template-columns: repeat(auto-fill, minmax(84px, 1fr)); gap: 8px; }
.panel {
  display: block;
  width: 100%;
  padding: 5px 5px 3px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  text-align: center;
}
.panel canvas { display: block; width: 100%; height: auto; aspect-ratio: 1; }
.panel span { display: block; font-size: 0.72rem; font-family: var(--mono); color: #c4cfda; margin-top: 2px; }
.panel.selected { border-color: var(--warm); box-shadow: 0 0 0 1px var(--warm) inset; }

.detail { position: sticky; top: 16px; }
.detail h3 { font-size: 1.3rem; font-family: var(--mono); margin-bottom: 2px; }
.detail .family { font-size: 0.85rem; color: #c4cfda; margin: 0 0 12px; }
.detail canvas { display: block; width: 100%; height: 130px; background: var(--bg); border-radius: 8px; border: 1px solid var(--border); }
.detail h4 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin: 14px 0 6px; }
.bars { list-style: none; margin: 0; padding: 0; font-size: 0.8rem; }
.bars li { display: grid; grid-template-columns: 68px 1fr 44px; align-items: center; gap: 8px; margin-bottom: 3px; }
.bars button { all: unset; cursor: pointer; font-family: var(--mono); color: var(--text); }
.bars button:hover { color: var(--warm); }
.bars button:focus-visible { outline: 2px solid var(--warm); }
.bar { height: 8px; border-radius: 99px; }
.bar.exc { background: var(--warm); }
.bar.inh { background: var(--cool); }
.bars .n { color: var(--muted); font-family: var(--mono); text-align: right; }

/* ---- flight simulator */
.flight-card, .train-card { margin-bottom: 20px; }
.flight-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; flex-wrap: wrap; }
.flight-top p { margin: 0; max-width: 640px; }
.spin { display: flex; flex-direction: column; align-items: flex-end; }
.spin strong { font: 600 2rem/1.1 var(--mono); color: var(--warm); }
#world {
  display: block;
  width: 100%;
  height: auto;
  margin: 14px 0 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg);
}
.flight-views { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.controls { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 14px 24px; margin: 18px 0 16px; }
.control { display: flex; flex-direction: column; gap: 6px; }
.control.buttons { flex-direction: row; margin-left: auto; }
.control-label { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); }
#pause-btn { width: 44px; }
#heading-plot { display: block; width: 100%; height: auto; border-radius: 10px; border: 1px solid var(--border); }
.plot-legend { display: flex; flex-wrap: wrap; gap: 6px 16px; align-items: center; margin-top: 8px; font-size: 0.85rem; }
.swatch { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; border: 1px solid var(--border); }
.swatch.off { background: rgba(141, 155, 171, 0.25); }
.swatch.simple { background: rgba(255, 180, 84, 0.55); }
.swatch.trained { background: rgba(76, 195, 255, 0.55); }

.train-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.train-grid p { font-size: 0.92rem; color: #c4cfda; }
.train-grid h3 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin: 18px 0 6px; }
.train-grid h3:first-child { margin-top: 4px; }
#train-btn { width: auto; padding: 12px 22px; }
.train-progress { margin-top: 14px; max-width: 360px; }
#train-bar { width: 0; height: 100%; background: var(--warm); transition: width 0.2s; }
.chart { list-style: none; margin: 0; padding: 0; font-size: 0.85rem; }
.chart li { display: grid; grid-template-columns: 150px 1fr 64px; align-items: center; gap: 10px; margin-bottom: 5px; }
.chart .name { font-family: var(--mono); white-space: nowrap; }
.chart .track { position: relative; height: 12px; background: var(--surface-2); border-radius: 99px; }
.chart .track.diverging::after { content: ""; position: absolute; left: 50%; top: -3px; bottom: -3px; width: 1px; background: #3a4b5e; }
.chart .fill { position: absolute; top: 0; bottom: 0; left: 0; border-radius: 99px; }
.chart .fill.pos { background: var(--warm); }
.chart .fill.neg { background: var(--cool); }
.chart .fill.mode-off { background: #8d9bab; }
.chart .fill.mode-simple { background: var(--warm); }
.chart .fill.mode-trained { background: var(--cool); }
.chart .n { font-family: var(--mono); color: #c4cfda; text-align: right; }

.about { margin-bottom: 40px; }
.about-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.about p { font-size: 0.9rem; color: #c4cfda; }

@media (max-width: 960px) {
  .stage, .brain-body, .about-grid, .train-grid { grid-template-columns: 1fr; }
  .control.buttons { margin-left: 0; }
  .detail { position: static; }
}
@media (max-width: 640px) {
  .flight-views { grid-template-columns: 1fr 1fr; gap: 10px; }
  .flight-views figure:last-child { grid-column: 1 / -1; width: 60%; margin: 0 auto; }
  .chart li { grid-template-columns: 110px 1fr 56px; }
}
@media (max-width: 520px) {
  .views { gap: 10px; }
  .panels { grid-template-columns: repeat(auto-fill, minmax(66px, 1fr)); gap: 6px; }
  .legend { width: 100%; }
}

/* ---- PolyTrack page */
.steps { padding-left: 20px; margin: 0 0 12px; color: #c4cfda; }
.steps li { margin-bottom: 10px; }
pre.url { margin: 8px 0 0; padding: 10px 12px; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; font: 0.9rem var(--mono); overflow-x: auto; color: var(--warm); }
kbd { font: 600 0.85em var(--mono); padding: 1px 6px; border: 1px solid var(--border); border-bottom-width: 2px; border-radius: 5px; background: var(--surface-2); color: var(--text); }