:root {
  color-scheme: light dark;
  --page-bg: #f8fafc;
  --page-text: #1e293b;
  --border: #e2e8f0;
  --surface: #ffffff;
  --surface-muted: #f1f5f9;
  --surface-elevated: #f8fafc;
  --control-bg: #f1f5f9;
  --control-bg-hover: #e2e8f0;
  --control-border: #cbd5e1;
  --control-text: #1e293b;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --danger: #dc2626;
  --danger-hover: #b91c1c;
  --note-bg: #fefce8;
  --note-border: #eab308;
  --note-text: #854d0e;
  --code-bg: #e2e8f0;
  --config-bg: #f0fdf4;
  --config-text: #047857;
  --checker-light: #e2e8f0;
  --checker-dark: #cbd5e1;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --page-bg: #0f1117;
  --page-text: #e2e8f0;
  --border: #2d3748;
  --surface: #141927;
  --surface-muted: #1a1f2e;
  --surface-elevated: #11161f;
  --control-bg: #2d3748;
  --control-bg-hover: #3d4a60;
  --control-border: #4a5568;
  --control-text: #e2e8f0;
  --note-bg: #1a1a0a;
  --note-border: #4a3f00;
  --note-text: #c8b84a;
  --code-bg: #2d3748;
  --config-bg: #11161f;
  --config-text: #9ad0bf;
  --checker-light: #334155;
  --checker-dark: #1e293b;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --page-bg: #0f1117;
    --page-text: #e2e8f0;
    --border: #2d3748;
    --surface: #141927;
    --surface-muted: #1a1f2e;
    --surface-elevated: #11161f;
    --control-bg: #2d3748;
    --control-bg-hover: #3d4a60;
    --control-border: #4a5568;
    --control-text: #e2e8f0;
    --note-bg: #1a1a0a;
    --note-border: #4a3f00;
    --note-text: #c8b84a;
    --code-bg: #2d3748;
    --config-bg: #11161f;
    --config-text: #9ad0bf;
    --checker-light: #334155;
    --checker-dark: #1e293b;
  }
}

body {
  font-family: system-ui, sans-serif;
  max-width: 980px;
  margin: 2rem auto;
  padding: 0 1rem;
  line-height: 1.5;
  background: var(--page-bg);
  color: var(--page-text);
}

.topbar {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
  margin: 0 0 1.5rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.75rem;
}

.topbar a {
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
  text-decoration: none;
  color: var(--control-text);
  border: 1px solid var(--control-border);
  background: var(--control-bg);
  font-size: 0.9rem;
}

.topbar a:hover {
  background: var(--control-bg-hover);
}

.topbar a.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.theme-toggle {
  margin-left: auto;
  min-width: 4.5rem;
  font-size: 0.9rem;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  margin: 1rem 0 0.75rem;
}

.playback-controls {
  display: flex;
  gap: 0.75rem;
  margin: 0 0 1.25rem;
}

.playback-controls button {
  min-width: 7rem;
  padding: 0.65rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
}

.playback-controls #start {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.playback-controls #start:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.playback-controls #stop {
  background: var(--danger);
  border-color: var(--danger);
  color: #fff;
}

.playback-controls #stop:hover {
  background: var(--danger-hover);
  border-color: var(--danger-hover);
}

.progress-control {
  display: grid;
  grid-template-columns: auto minmax(180px, 1fr) 3rem;
  gap: 0.75rem;
  align-items: center;
  margin: 1rem 0 1.5rem;
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin: 1.5rem 0 0.75rem;
}

.section-head h2 {
  margin: 0;
  font-size: 1.1rem;
}

.section-head .progress-control {
  margin: 0;
}

.spinner-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.prefab-grid {
  grid-template-columns: minmax(0, 1fr);
}

.prefab-grid .stage {
  height: 680px;
  min-height: 680px;
}

.spinner-card {
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
}

.spinner-card h2 {
  margin: 0;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border);
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.card-playback {
  display: flex;
  gap: 0.35rem;
  flex-shrink: 0;
}

.card-playback button {
  padding: 0.25rem 0.55rem;
  font-size: 0.8rem;
  font-weight: 600;
}

.card-playback .card-start {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.card-playback .card-start:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.card-playback .card-stop {
  background: var(--danger);
  border-color: var(--danger);
  color: #fff;
}

.card-playback .card-stop:hover {
  background: var(--danger-hover);
  border-color: var(--danger-hover);
}

select {
  background: var(--control-bg);
  color: var(--control-text);
  border: 1px solid var(--control-border);
  border-radius: 6px;
  padding: 0.2rem 0.4rem;
  font: inherit;
  font-size: 0.85rem;
}

.stage {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 340px;
  min-height: 340px;
  font-size: 1.25rem;
  background: var(--surface-muted);
}

.stage.checker-stage {
  background-color: var(--checker-light);
  background-image: conic-gradient(
    var(--checker-dark) 25%,
    var(--checker-light) 0 50%,
    var(--checker-dark) 0 75%,
    var(--checker-light) 0
  );
  background-size: 32px 32px;
}

.transparency-controls {
  display: grid;
  gap: 0.5rem;
  padding: 0.65rem 1rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface-elevated);
}

.transparency-controls label {
  display: grid;
  grid-template-columns: 4rem minmax(0, 1fr) 3rem;
  gap: 0.65rem;
}

.transparency-controls output {
  text-align: right;
  font-variant-numeric: tabular-nums;
}

label {
  display: inline-flex;
  gap: 0.4rem;
  align-items: center;
}

button {
  padding: 0.4rem 0.8rem;
  cursor: pointer;
  background: var(--control-bg);
  color: var(--control-text);
  border: 1px solid var(--control-border);
  border-radius: 6px;
}

button:hover {
  background: var(--control-bg-hover);
}

.note {
  background: var(--note-bg);
  border: 1px solid var(--note-border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  color: var(--note-text);
}

code {
  background: var(--code-bg);
  padding: 0.1rem 0.3rem;
  border-radius: 4px;
}

.showcase-title {
  margin: 2rem 0 0.5rem;
  font-size: 1.2rem;
}

.card-control {
  padding: 0.5rem 1rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.85rem;
}

.spinner-card .config {
  margin: 0;
  padding: 0.6rem 0.85rem;
  font-size: 0.72rem;
  line-height: 1.45;
  color: var(--config-text);
  background: var(--config-bg);
  border-top: 1px solid var(--border);
  white-space: pre-wrap;
  overflow-x: auto;
}


.card-progress {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 1rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.85rem;
}

.card-progress input[type="range"] {
  flex: 1;
}

.card-progress output {
  min-width: 3rem;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.card-story {
  margin: 0;
  padding: 0.6rem 1rem;
  font-size: 0.82rem;
  color: var(--muted, inherit);
  opacity: 0.85;
  border-top: 1px solid var(--border);
}

@media (max-width: 700px) {

  .spinner-grid,
  .progress-control {
    grid-template-columns: 1fr;
  }

  .theme-toggle {
    margin-left: 0;
  }

  .prefab-grid .stage {
    height: 520px;
    min-height: 520px;
  }
}