html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.row {
  display: flex;
  gap: 24px;
}

.pane {
  box-sizing: border-box;
  width: clamp(96px, 26vmin, 130px);
  aspect-ratio: 1;
  border-radius: 16px;
  display: grid;
  place-items: center;
}

.pane--light {
  background: #ffffff;
  color-scheme: light;
}

.pane--dark {
  background: #17141a;
  color-scheme: dark;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.badge {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: light-dark(#e9e2ff, #1c1630);
  --glow-rest: light-dark(rgba(124, 92, 255, 0), rgba(124, 92, 255, 0.2));
  --glow-peak: light-dark(rgba(124, 92, 255, 0.7), #7c5cff);
  --glow-peak-soft: light-dark(rgba(124, 92, 255, 0.3), rgba(124, 92, 255, 0.7));
  box-shadow: 0 0 4px var(--glow-rest);
}

.stage.is-demo .badge {
  animation: breathe 2s ease-in-out infinite;
}

@keyframes breathe {
  0%, 15%, 85%, 100% {
    box-shadow: 0 0 4px var(--glow-rest);
  }
  35%, 65% {
    box-shadow: 0 0 16px var(--glow-peak), 0 0 40px var(--glow-peak-soft);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .badge {
    animation: none;
  }
}