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);
}

@property --x {
  syntax: "<percentage>";
  inherits: false;
  initial-value: 50%;
}
@property --y {
  syntax: "<percentage>";
  inherits: false;
  initial-value: 50%;
}
.card {
  position: relative;
  overflow: hidden;
  box-sizing: border-box;
  width: clamp(200px, 62vmin, 300px);
  aspect-ratio: 4/3;
  border-radius: 16px;
  background: #17141a;
  border: 1px solid rgba(255, 255, 255, 0.1);
  padding: 16px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 8px;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--x) var(--y), rgba(179, 107, 255, 0.55), transparent 55%);
  pointer-events: none;
}

.thumb {
  position: absolute;
  top: 16px;
  left: 16px;
  right: 16px;
  height: 46%;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.08);
}

.bar {
  display: block;
  height: 8px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.18);
}

.bar--lg {
  width: 65%;
}

.bar--sm {
  width: 40%;
}

.stage.is-demo .card::before {
  animation: sweep 2s ease-in-out infinite;
}

@keyframes sweep {
  0% {
    --x: 18%;
    --y: 20%;
  }
  25% {
    --x: 85%;
    --y: 22%;
  }
  50% {
    --x: 78%;
    --y: 80%;
  }
  75% {
    --x: 20%;
    --y: 76%;
  }
  100% {
    --x: 18%;
    --y: 20%;
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .card::before {
    animation: none;
    --x: 50%;
    --y: 50%;
  }
}