:root {
  --background: #07090d;
  --surface: #10141b;
  --surface-raised: #151b24;
  --line: #27303d;
  --line-strong: #394556;
  --text: #f5f7fb;
  --muted: #9da8b8;
  --accent: #32e6a1;
  --accent-rgb: 50, 230, 161;
  --output: #70a7ff;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--background);
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 12% -8%, rgba(var(--accent-rgb), 0.11), transparent 31rem),
    var(--background);
  color: var(--text);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  -webkit-font-smoothing: antialiased;
}

body[data-dataset="nuscenes"] {
  --accent: #ff9a62;
  --accent-rgb: 255, 154, 98;
}

button, video { font: inherit; }
a { color: inherit; }

.site-header {
  border-bottom: 1px solid var(--line);
  background: rgba(7, 9, 13, 0.9);
}

.header-inner,
.explorer-inner,
main {
  width: min(100%, 1800px);
  margin: 0 auto;
}

.header-inner { padding: 24px clamp(14px, 2.5vw, 44px) 32px; }

.topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.back-link,
.dataset-switch {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 0.73rem;
  font-weight: 760;
  letter-spacing: 0.08em;
  text-decoration: none;
  text-transform: uppercase;
  transition: color 160ms ease;
}

.back-link:hover,
.back-link:focus-visible,
.dataset-switch:hover,
.dataset-switch:focus-visible {
  color: var(--accent);
  outline: none;
}

.dataset-switch {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 9px 13px;
  background: var(--surface);
}

.hero-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 32px;
  margin-top: clamp(36px, 5vw, 66px);
}

.eyebrow {
  margin: 0 0 9px;
  color: var(--accent);
  font-size: 0.7rem;
  font-weight: 820;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(3.5rem, 8vw, 7.7rem);
  font-weight: 770;
  letter-spacing: -0.075em;
  line-height: 0.84;
}

.intro {
  width: min(100%, 520px);
  margin: 0 0 2px;
  color: var(--muted);
  font-size: clamp(0.9rem, 1.4vw, 1.02rem);
  line-height: 1.65;
}

.explorer-bar {
  position: sticky;
  z-index: 20;
  top: 0;
  border-bottom: 1px solid var(--line);
  background: rgba(7, 9, 13, 0.88);
  backdrop-filter: blur(18px);
}

.explorer-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(14px, 3vw, 34px);
  min-height: 84px;
  padding: 10px clamp(10px, 2.5vw, 44px);
}

.control-label {
  display: block;
  margin-bottom: 6px;
  color: #718095;
  font-size: 0.6rem;
  font-weight: 820;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.distance-tabs {
  display: flex;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #0c1016;
}

.distance-tab {
  display: flex;
  min-width: 104px;
  align-items: baseline;
  justify-content: center;
  gap: 7px;
  border: 0;
  border-radius: 10px;
  padding: 10px 12px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  transition: background 160ms ease, color 160ms ease, box-shadow 160ms ease;
}

.distance-short {
  font-size: 1rem;
  font-weight: 850;
  letter-spacing: -0.03em;
}

.distance-name {
  font-size: 0.68rem;
  font-weight: 700;
}

.distance-tab:hover,
.distance-tab:focus-visible {
  color: var(--text);
  outline: none;
}

.distance-tab[aria-selected="true"] {
  background: rgba(var(--accent-rgb), 0.13);
  color: var(--accent);
  box-shadow: inset 0 0 0 1px rgba(var(--accent-rgb), 0.35);
}

.direction-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
}

.direction-nav a {
  display: flex;
  min-width: 68px;
  align-items: center;
  justify-content: center;
  gap: 7px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 9px 12px;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.66rem;
  font-weight: 760;
  text-decoration: none;
  transition: border-color 160ms ease, background 160ms ease, color 160ms ease;
}

.direction-nav strong {
  color: var(--text);
  font-size: 0.83rem;
}

.direction-nav a:hover,
.direction-nav a:focus-visible {
  border-color: var(--accent);
  background: rgba(var(--accent-rgb), 0.1);
  color: var(--accent);
  outline: none;
}

.result-count {
  color: var(--muted);
  font-size: 0.69rem;
  font-weight: 720;
  text-align: right;
  white-space: nowrap;
}

.result-count strong {
  display: block;
  color: var(--text);
  font-size: 0.86rem;
}

main { padding: 0 clamp(10px, 2.5vw, 44px) 86px; }

.view-section {
  padding-top: clamp(48px, 6vw, 78px);
  scroll-margin-top: 82px;
}

.section-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 22px;
  margin-bottom: 23px;
}

.section-title-group {
  display: flex;
  align-items: baseline;
  gap: 15px;
}

.section-heading h2 {
  margin: 0;
  color: var(--accent);
  font-size: clamp(2.7rem, 5vw, 5rem);
  letter-spacing: -0.06em;
  line-height: 0.86;
}

.section-heading p,
.section-count {
  margin: 0;
  color: var(--muted);
  font-size: 0.7rem;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.comparison-list {
  display: grid;
  gap: clamp(28px, 4vw, 58px);
}

.comparison { min-width: 0; }

.comparison-meta {
  display: flex;
  min-height: 42px;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 10px;
}

.sequence-info { min-width: 0; }

.sequence-label {
  display: block;
  color: var(--text);
  font-size: 0.86rem;
  font-weight: 770;
}

.scene-id {
  display: block;
  overflow: hidden;
  margin-top: 3px;
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.66rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sync-button {
  flex: 0 0 auto;
  min-width: 98px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 8px 14px;
  background: var(--surface-raised);
  color: var(--text);
  cursor: pointer;
  font-size: 0.71rem;
  font-weight: 770;
  transition: border-color 160ms ease, background 160ms ease, color 160ms ease;
}

.sync-button:hover,
.sync-button:focus-visible,
.sync-button.is-playing {
  border-color: var(--accent);
  background: rgba(var(--accent-rgb), 0.12);
  color: var(--accent);
  outline: none;
}

.video-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(6px, 1vw, 16px);
}

.video-card {
  position: relative;
  min-width: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: clamp(10px, 1.4vw, 18px);
  background: #000;
  box-shadow: 0 16px 50px rgba(0, 0, 0, 0.2);
}

.video-label {
  display: flex;
  height: 36px;
  align-items: center;
  gap: 8px;
  padding: 0 12px;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 820;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.video-label::before {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  content: "";
}

.video-card.output .video-label::before { background: var(--output); }

video {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  background: #000;
  object-fit: contain;
}

.video-error {
  display: none;
  position: absolute;
  inset: 36px 0 0;
  place-items: center;
  padding: 18px;
  background: #090b0f;
  color: #ffb49e;
  font-size: 0.75rem;
  text-align: center;
}

.video-card.has-error .video-error { display: grid; }

.page-footer {
  width: min(100%, 1800px);
  margin: 70px auto 0;
  padding: 22px clamp(10px, 2.5vw, 44px) 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.72rem;
}

@media (max-width: 820px) {
  .hero-row { display: block; }
  .intro { margin-top: 24px; }
  .explorer-inner { grid-template-columns: auto 1fr; min-height: 78px; }
  .direction-nav { justify-content: flex-end; }
  .result-count { display: none; }
}

@media (max-width: 570px) {
  .header-inner { padding-top: 18px; padding-bottom: 26px; }
  .dataset-switch { padding: 8px 11px; font-size: 0.62rem; }
  .hero-row { margin-top: 38px; }
  .explorer-inner { grid-template-columns: 1fr; gap: 7px; padding-top: 8px; padding-bottom: 8px; }
  .control-label { display: none; }
  .distance-tabs { width: 100%; }
  .distance-tab { min-width: 0; flex: 1; padding: 8px 10px; }
  .direction-nav { justify-content: stretch; }
  .direction-nav a { min-width: 0; flex: 1; padding: 7px 9px; }
  .direction-nav span { display: none; }
  .view-section { scroll-margin-top: 126px; }
  .section-heading { margin-bottom: 15px; }
  .section-title-group { gap: 10px; }
  .section-heading p, .section-count { font-size: 0.58rem; }
  .scene-id { max-width: 58vw; }
  .sync-button { min-width: 82px; padding: 7px 10px; font-size: 0.64rem; }
  .video-label { height: 29px; padding: 0 8px; font-size: 0.59rem; }
  .video-error { inset: 29px 0 0; }
}

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