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

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

.stage {
  padding: clamp(8px, 2.4vw, 16px);
  position: relative;
  overflow: hidden;
}

.bg-blob {
  position: absolute;
  inset: -20%;
  background: radial-gradient(circle at 30% 30%, #2f6df6, transparent 60%), radial-gradient(circle at 70% 70%, #c2361a, transparent 60%);
}

.card {
  position: relative;
  z-index: 1;
  width: min(150px, 48vw);
  aspect-ratio: 4/3;
  border-radius: 16px;
  padding: 12px;
  box-sizing: border-box;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(6px) saturate(120%);
  -webkit-backdrop-filter: blur(6px) saturate(120%);
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  outline: none;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  justify-content: center;
  transform: translateY(0);
  transition: backdrop-filter 300ms ease-out, background 300ms ease-out, box-shadow 300ms ease-out, transform 300ms ease-out;
}

.card__title {
  margin: 0 0 4px;
  font-weight: 700;
  font-size: clamp(12px, 3.4vw, 14px);
  line-height: 1.3;
  font-family: inherit;
  color: #17141a;
}

.card__meta {
  margin: 0;
  font-weight: 500;
  font-size: clamp(11px, 3vw, 12px);
  line-height: 1.3;
  font-family: inherit;
  color: rgba(23, 20, 26, 0.85);
}

.card:hover,
.card:focus-visible,
.card:active {
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
  background: rgba(255, 255, 255, 0.26);
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  transform: translateY(-4px);
}

.card.is-demo {
  animation: glass-loop 2s ease-out infinite;
}

@keyframes glass-loop {
  0%, 15% {
    backdrop-filter: blur(6px) saturate(120%);
    background: rgba(255, 255, 255, 0.14);
    box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
    transform: translateY(0);
  }
  45%, 75% {
    backdrop-filter: blur(14px) saturate(160%);
    background: rgba(255, 255, 255, 0.26);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
    transform: translateY(-4px);
  }
  100% {
    backdrop-filter: blur(6px) saturate(120%);
    background: rgba(255, 255, 255, 0.14);
    box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
    transform: translateY(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .card {
    transition: none;
  }
  .card.is-demo {
    animation: none;
    backdrop-filter: blur(14px) saturate(160%);
    background: rgba(255, 255, 255, 0.26);
    transform: none;
  }
}