:root {
  --paper: #f4f0e8;
  --paper-2: #ebe5d9;
  --card: #fdfbf7;
  --ink: #1d1a17;
  --ink-2: #5c554d;
  --ink-3: #8b8378;
  --rule: #ddd5c7;
  --accent: #b4382a;
  --on-accent: #fff;
  --panel: #0e0c12;
  --shadow: 0 1px 0 rgb(0 0 0 / 0.02), 0 10px 28px -18px rgb(60 40 20 / 0.35);
  --serif: "Newsreader", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #14120f;
    --paper-2: #1b1814;
    --card: #1c1915;
    --ink: #efe9df;
    --ink-2: #b3aa9d;
    --ink-3: #82796d;
    --rule: #332e27;
    --accent: #e0604f;
    --shadow: 0 10px 28px -18px rgb(0 0 0 / 0.8);
    color-scheme: dark;
  }
}

*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 72px; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 16px/1.55 var(--sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; }
code, kbd { font-family: var(--mono); }
img { display: block; max-width: 100%; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

.eyebrow {
  font: 500 12px/1 var(--mono);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-3);
}

/* ---------- nav ---------- */
.topnav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--rule);
}
.topnav .wrap { display: flex; align-items: center; gap: 24px; height: 52px; }
.brand { font: 600 13px/1 var(--mono); letter-spacing: 0.16em; text-decoration: none; }
.brand i { color: var(--accent); font-style: normal; }
.topnav ul {
  display: flex; gap: 4px; margin: 0 0 0 auto; padding: 0; list-style: none;
  overflow-x: auto; scrollbar-width: none;
}
.topnav ul::-webkit-scrollbar { display: none; }
.topnav li a {
  display: block; padding: 7px 12px; border-radius: 999px; white-space: nowrap;
  font-size: 13.5px; color: var(--ink-2); text-decoration: none;
}
.topnav li a:hover { color: var(--ink); background: var(--paper-2); }
.topnav li a[aria-current="true"] { color: var(--ink); background: var(--paper-2); font-weight: 500; }

/* ---------- hero ---------- */
.hero { padding: 72px 0 56px; }
.hero h1 {
  margin: 18px 0 14px;
  font: 500 clamp(64px, 13vw, 132px)/0.92 var(--serif);
  letter-spacing: -0.035em;
}
.hero h1 span { color: var(--accent); }
.expansion {
  margin: 0; max-width: 30ch;
  font: 400 clamp(22px, 3.2vw, 32px)/1.25 var(--serif);
  color: var(--ink-2);
}
.expansion b { font-weight: 600; color: var(--ink); }
.byline { margin: 28px 0 0; color: var(--ink-2); font-size: 15px; }
.byline strong { color: var(--ink); font-weight: 500; }
.pills { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.pill {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 16px; border-radius: 999px;
  border: 1px solid var(--rule); background: var(--card);
  font-size: 14px; font-weight: 500; text-decoration: none;
}
.pill:hover:not([aria-disabled]) { border-color: var(--ink); }
.pill.primary { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.pill[aria-disabled] { color: var(--ink-3); cursor: default; }
.pill small { font: 500 10px/1 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ink-3); }

/* ---------- overview ---------- */
.overview { padding: 64px 0; border-top: 1px solid var(--rule); }
.overview-grid { display: grid; grid-template-columns: 200px 1fr; gap: 24px 48px; }
.overview h2, .dataset h2 { margin: 0; font: 500 clamp(32px, 4.4vw, 44px)/1.08 var(--serif); letter-spacing: -0.015em; }
.abstract { margin: 0; max-width: 68ch; font: 400 19px/1.62 var(--serif); }
.keywords { display: flex; flex-wrap: wrap; gap: 8px; margin: 22px 0 0; padding: 0; list-style: none; }
.keywords li {
  padding: 5px 11px; border-radius: 999px; border: 1px solid var(--rule);
  font: 400 12px/1.2 var(--mono); color: var(--ink-2);
}
.figure { margin: 44px 0 0; }
.figure .frame {
  background: #fff; border: 1px solid var(--rule); border-radius: 14px; padding: 12px;
  box-shadow: var(--shadow);
}
.figure img { width: 100%; height: auto; }
.figure figcaption { margin: 12px 4px 0; max-width: 80ch; font-size: 14px; color: var(--ink-2); }
.figure figcaption b { color: var(--ink); font-weight: 600; }

/* ---------- how to listen ---------- */
.guide { padding: 0 0 56px; }
.guide-box {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 0;
  background: var(--card); border: 1px solid var(--rule); border-radius: 14px; overflow: hidden;
}
.guide-box > div { padding: 20px 22px; }
.guide-box > div + div { border-left: 1px solid var(--rule); }
.guide-box .n { font: 500 12px/1 var(--mono); color: var(--accent); letter-spacing: 0.1em; }
.guide-box h3 { margin: 10px 0 6px; font: 500 20px/1.2 var(--serif); }
.guide-box p { margin: 0; font-size: 14px; color: var(--ink-2); }
.guide-box kbd {
  display: inline-block; padding: 1px 6px; border: 1px solid var(--rule); border-bottom-width: 2px;
  border-radius: 5px; background: var(--paper); font-size: 11.5px; color: var(--ink);
}
.guide-foot { margin: 14px 4px 0; font-size: 13.5px; color: var(--ink-3); }

/* ---------- datasets ---------- */
.dataset { padding: 64px 0 24px; border-top: 1px solid var(--rule); }
.dataset-head { display: grid; grid-template-columns: 200px 1fr; gap: 12px 48px; align-items: baseline; margin-bottom: 8px; }
.dataset-head .eyebrow { grid-row: span 2; }
.dataset-head h2 { grid-column: 2; }
.lede { grid-column: 2; margin: 8px 0 0; max-width: 68ch; font: 400 18px/1.55 var(--serif); color: var(--ink-2); }

.group { margin-top: 44px; }
.group-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 4px 20px; margin-bottom: 18px; }
.group-head h3 { margin: 0; font: 500 26px/1.2 var(--serif); }
.group-head p { margin: 0; color: var(--ink-3); font-size: 14.5px; }
.cards { display: grid; gap: 22px; }
.group:not(:has(.group-head)) { margin-top: 32px; }

/* ---------- card ---------- */
.card {
  background: var(--card); border: 1px solid var(--rule); border-radius: 16px;
  padding: 20px 22px 18px; box-shadow: var(--shadow);
  transition: border-color 0.2s;
}
.card.is-playing { border-color: color-mix(in srgb, var(--accent) 50%, var(--rule)); }
.card-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 6px 16px; margin-bottom: 14px; }
.card-head h4 { margin: 0; font: 500 22px/1.2 var(--serif); }

.spec {
  position: relative; height: clamp(150px, 24vw, 232px);
  background: var(--panel); border-radius: 10px; overflow: hidden;
  cursor: pointer; touch-action: pan-y; user-select: none; -webkit-user-select: none;
  outline-offset: 3px;
}
.spec img {
  position: absolute; inset: 0; width: 100%; height: 100%; object-fit: fill;
  opacity: 0; transition: opacity 0.22s ease; pointer-events: none;
}
.spec img.is-on { opacity: 1; }
.fline { position: absolute; left: 0; right: 0; border-top: 1px dashed rgb(255 255 255 / 0.13); pointer-events: none; }
.fline span {
  position: absolute; right: 8px; bottom: 3px;
  font: 400 10px/1 var(--mono); color: rgb(255 255 255 / 0.62); text-shadow: 0 0 4px #000;
}
.chip {
  position: absolute; left: 10px; top: 10px; display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 10px; border-radius: 7px; pointer-events: none;
  background: rgb(14 12 18 / 0.72); backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px);
  color: #fff; font: 500 11px/1 var(--mono); letter-spacing: 0.1em; text-transform: uppercase;
}
.chip .dot, .mbtn .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--c); flex: none; }
.playhead {
  position: absolute; top: 0; bottom: 0; left: 0; width: 2px; margin-left: -1px;
  background: #fff; pointer-events: none;
  box-shadow: 0 0 0 1px rgb(0 0 0 / 0.35), 0 0 14px rgb(255 255 255 / 0.55);
}
.playhead::before {
  content: ""; position: absolute; top: 0; left: 50%; width: 10px; height: 10px;
  transform: translate(-50%, -1px) rotate(45deg) translate(0, -50%);
  background: #fff; border-radius: 2px;
}
.hover {
  position: absolute; top: 0; bottom: 0; width: 1px; background: rgb(255 255 255 / 0.5);
  pointer-events: none; opacity: 0;
}
.hover span {
  position: absolute; bottom: 8px; left: 6px; padding: 3px 6px; border-radius: 4px;
  background: rgb(14 12 18 / 0.8); color: #fff; font: 500 10.5px/1 var(--mono); white-space: nowrap;
}
.hover.flip span { left: auto; right: 6px; }

.taxis { position: relative; height: 20px; margin-top: 6px; font: 400 10.5px/1 var(--mono); color: var(--ink-3); }
.taxis span { position: absolute; top: 4px; transform: translateX(-50%); }
.taxis span:first-child { transform: none; }
.taxis span.end { transform: translateX(-100%); }

.controls { display: flex; align-items: center; gap: 14px; margin-top: 6px; }
.play {
  flex: none; width: 48px; height: 48px; border-radius: 50%; border: 0; padding: 0;
  display: grid; place-items: center; cursor: pointer;
  background: var(--accent); color: var(--on-accent);
  box-shadow: 0 6px 16px -8px var(--accent);
  transition: transform 0.15s ease, filter 0.15s;
}
.play:hover { transform: scale(1.06); filter: brightness(1.06); }
.play:active { transform: scale(0.97); }
.play svg { width: 22px; height: 22px; fill: currentColor; }
.play svg.spin { fill: none; animation: spin 0.9s linear infinite; }
.play:focus-visible, .mbtn:focus-visible, .pill:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; }
.clock { font: 500 14px/1 var(--mono); font-variant-numeric: tabular-nums; }
.clock span:last-child { color: var(--ink-3); }
.status { margin-left: auto; font-size: 13px; color: var(--ink-3); text-align: right; }
.status.err { color: var(--accent); }

.switcher { display: flex; flex-direction: column; gap: 12px; margin-top: 16px; }
.mrow + .mrow { padding-top: 10px; border-top: 1px dashed var(--rule); }
.mrow-body { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 22px; }
.mrow-body[hidden] { display: none; }
.mrow-toggle {
  display: flex; align-items: center; gap: 10px; width: 100%; margin: 0 0 2px; padding: 6px 2px;
  border: 0; background: none; cursor: pointer; text-align: left; color: var(--ink-2);
  font: 500 11px/1 var(--mono); letter-spacing: 0.12em; text-transform: uppercase;
}
.mrow-toggle:hover { color: var(--ink); }
.mrow-toggle:focus-visible { outline: 2px solid var(--ink); outline-offset: 3px; border-radius: 4px; }
.mrow-toggle .chev {
  width: 6px; height: 6px; border-right: 1.6px solid currentColor; border-bottom: 1.6px solid currentColor;
  transform: rotate(-45deg); transition: transform 0.15s ease; margin: 0 3px 0 2px;
}
.mrow-toggle[aria-expanded="true"] .chev { transform: rotate(45deg); }
.mrow-toggle .count { padding: 2px 6px; border-radius: 999px; border: 1px solid var(--rule); font-size: 10px; letter-spacing: 0; }
.mrow-toggle .act { margin-left: auto; color: var(--ink-3); }
.mrow-toggle:hover .act { color: var(--accent); }
.msub { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.msub-label { font: 500 10px/1 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-3); margin-right: 2px; }
.mbtn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 14px; border-radius: 999px; cursor: pointer;
  border: 1px solid var(--rule); background: transparent; color: var(--ink);
  font: 500 14px/1 var(--sans);
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}
.mbtn:hover { border-color: var(--ink); }
.mbtn em {
  font: 500 9.5px/1 var(--mono); font-style: normal; letter-spacing: 0.08em; text-transform: uppercase;
  padding: 3px 5px; border-radius: 4px; background: color-mix(in srgb, var(--accent) 14%, transparent); color: var(--accent);
}
.mbtn kbd { font-size: 10.5px; color: var(--ink-3); border: 1px solid var(--rule); border-radius: 4px; padding: 1px 5px; }
.mbtn.is-ours { border-color: color-mix(in srgb, var(--accent) 55%, var(--rule)); }
.mbtn[aria-pressed="true"] { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.mbtn[aria-pressed="true"] kbd { color: inherit; border-color: color-mix(in srgb, currentColor 35%, transparent); opacity: 0.7; }
.mbtn.is-ours[aria-pressed="true"] { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.mbtn.is-ours[aria-pressed="true"] em { background: rgb(255 255 255 / 0.22); color: inherit; }
.mbtn[aria-pressed="true"] .dot { box-shadow: 0 0 0 2px rgb(255 255 255 / 0.85); }
.mbtn.is-loading .dot { animation: pulse 1s ease-in-out infinite; }

.note { margin: 12px 2px 0; min-height: 2.9em; max-width: 84ch; font-size: 13.5px; color: var(--ink-2); }

/* ---------- misc ---------- */
.banner {
  margin: 16px 0 0; padding: 12px 16px; border-radius: 10px;
  background: color-mix(in srgb, var(--accent) 10%, var(--card)); border: 1px solid color-mix(in srgb, var(--accent) 40%, var(--rule));
  font-size: 14px;
}
.banner code { font-size: 13px; }
.fatal { padding: 48px 0; color: var(--accent); }
footer { margin-top: 72px; padding: 32px 0 64px; border-top: 1px solid var(--rule); color: var(--ink-3); font-size: 13.5px; }
footer p { margin: 0 0 6px; max-width: 80ch; }
.debug-toggle {
  margin-top: 14px; padding: 5px 10px; border-radius: 999px; cursor: pointer;
  border: 1px dashed var(--rule); background: none; color: var(--ink-3);
  font: 500 11px/1 var(--mono); letter-spacing: 0.04em;
}
.debug-toggle .state { font-weight: 600; color: var(--ink-2); }
.debug-toggle:hover { border-color: var(--ink-2); color: var(--ink-2); }
.debug-toggle[aria-pressed="true"] { border-style: solid; border-color: var(--accent); color: var(--accent); }
.debug-toggle[aria-pressed="true"] .state { color: var(--accent); }

@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 50% { opacity: 0.25; } }

@media (max-width: 820px) {
  .overview-grid, .dataset-head { grid-template-columns: 1fr; }
  .dataset-head .eyebrow { grid-row: auto; }
  .dataset-head h2, .lede { grid-column: 1; }
  .guide-box { grid-template-columns: 1fr; }
  .guide-box > div + div { border-left: 0; border-top: 1px solid var(--rule); }
}
@media (max-width: 640px) {
  .wrap { padding: 0 16px; }
  .hero { padding: 44px 0 40px; }
  .card { padding: 14px 14px 14px; border-radius: 14px; }
  .mbtn kbd { display: none; }
  .mbtn { padding: 10px 13px; }
  .status { display: none; }
  .brand { display: none; }
  .topnav ul { margin-left: 0; }
}
@media (hover: none) { .mbtn kbd { display: none; } }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .spec img, .play, .mbtn, .mrow-toggle .chev { transition: none; }
  .mbtn.is-loading .dot { animation: none; }
}