:root {
  /* Naming: --demo-* tokens and .demo-* components are shared; scene styles
     stay behind a .demo-scene--<name> root and may override semantic roles. */

  /* Color roles. Scenes may override these without changing the controls. */
  --demo-color-accent: #1a73e8;
  --demo-color-text: #202124;
  --demo-color-muted: #5f6368;
  --demo-color-surface: #ffffff;
  --demo-color-control: #f1f3f4;
  --demo-color-control-hover: #e4e6e8;
  --demo-color-track: #dadce0;

  /* Shared layout, shape, depth, and motion tokens. */
  --demo-space-1: 4px;
  --demo-space-2: 8px;
  --demo-space-3: 12px;
  --demo-space-4: 16px;
  --demo-space-5: 20px;
  --demo-radius-sm: 6px;
  --demo-radius-md: 10px;
  --demo-radius-round: 999px;
  /* Shadow ink: light rgb(35 28 102) = color-mix(#3429ff 30%, #1c1725);
     dark rgb(56 39 51) = color-mix(#efa9ae 20%, #0a0614); see --shadow-rgb
     in assets/css/main.css. */
  --demo-shadow-control: 0 1px 4px rgb(35 28 102 / 38%);
  --demo-motion-fast: 120ms;
  --demo-motion-base: 200ms;
  --demo-ease-standard: cubic-bezier(0.2, 0, 0, 1);
  --demo-control-size: 34px;
  --demo-timeline-width: 560px;
  --demo-timeline-gutter: 40px;
}

:root.dark {
  --demo-color-accent: #8ab4f8;
  --demo-color-text: #e8eaed;
  --demo-color-muted: #9aa0a6;
  --demo-color-surface: #202124;
  --demo-color-control: #3c4043;
  --demo-color-control-hover: #4b4f52;
  --demo-color-track: #5f6368;
  --demo-shadow-control: 0 1px 4px rgb(56 39 51 / 55%);
}

.demo-scene {
  margin: 0;
  color: var(--demo-color-text);
}

.demo-timeline {
  position: fixed;
  z-index: 50;
  bottom: var(--demo-space-4);
  left: 50%;
  display: flex;
  width: min(
    var(--demo-timeline-width),
    calc(100vw - var(--demo-timeline-gutter) - var(--demo-timeline-gutter))
  );
  align-items: center;
  gap: var(--demo-space-3);
  transform: translateX(-50%);
  user-select: none;
}

.demo-timeline__button {
  display: inline-flex;
  flex: 0 0 auto;
  width: var(--demo-control-size);
  height: var(--demo-control-size);
  align-items: center;
  justify-content: center;
  padding: 0;
  border: 0;
  border-radius: var(--demo-radius-round);
  background: var(--demo-color-control);
  color: var(--demo-color-text);
  cursor: pointer;
  font: inherit;
  font-size: 16px;
  line-height: 1;
  transition:
    color var(--demo-motion-base) var(--demo-ease-standard),
    background-color var(--demo-motion-base) var(--demo-ease-standard);
}

.demo-timeline__button:hover {
  background: var(--demo-color-control-hover);
}

.demo-timeline__button:focus-visible,
.demo-timeline__track:focus-visible {
  outline: 2px solid var(--demo-color-accent);
  outline-offset: 3px;
}

.demo-timeline__track {
  position: relative;
  flex: 1 1 auto;
  height: 6px;
  border-radius: var(--demo-radius-round);
  background: var(--demo-color-track);
  cursor: pointer;
  touch-action: none;
  transition: background-color var(--demo-motion-base) var(--demo-ease-standard);
}

.demo-timeline__fill,
.demo-timeline__thumb {
  position: absolute;
  left: 0;
  background: var(--demo-color-accent);
}

.demo-timeline__fill {
  top: 0;
  bottom: 0;
  width: 0;
  border-radius: inherit;
}

.demo-timeline__thumb {
  top: 50%;
  width: 14px;
  height: 14px;
  border-radius: var(--demo-radius-round);
  box-shadow: var(--demo-shadow-control);
  transform: translate(-50%, -50%);
  transition: transform var(--demo-motion-fast) var(--demo-ease-standard);
}

.demo-timeline__track:hover .demo-timeline__thumb,
.demo-timeline.is-dragging .demo-timeline__thumb {
  transform: translate(-50%, -50%) scale(1.25);
}

.demo-timeline__time {
  position: absolute;
  overflow: hidden;
  width: 1px;
  height: 1px;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.is-card .demo-timeline {
  display: none;
}

/* These state classes deliberately apply to the whole scene. */
.is-paused *,
.is-paused *::before,
.is-paused *::after {
  animation-play-state: paused !important;
}

.is-seeking *,
.is-seeking *::before,
.is-seeking *::after {
  transition: none !important;
  animation: none !important;
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --demo-motion-fast: 0ms;
    --demo-motion-base: 0ms;
  }

  .demo-timeline *,
  .demo-timeline *::before,
  .demo-timeline *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}