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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.stage {
  padding: clamp(6px, 2.4vw, 16px);
}

.card {
  position: relative;
  width: min(150px, 48vw);
  border-radius: 16px;
  background: #fff7e6;
  overflow: hidden;
  cursor: pointer;
  touch-action: manipulation;
  transform: scale(1);
  filter: brightness(1);
  transition: transform 220ms ease-out, filter 220ms ease-out;
}
.card::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  box-shadow: inset 0 0 0 0 rgba(47, 109, 246, 0.4), inset 0 0 0 0 rgba(47, 109, 246, 0.22);
  opacity: 0;
  pointer-events: none;
}

.card__media {
  display: block;
  aspect-ratio: 16/9;
  background: linear-gradient(155deg, #2f6df6 0%, #17141a 100%);
}

.card__body {
  padding: 8px 12px;
}

.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, 0.6);
}

.card:active {
  transform: scale(0.98);
  filter: brightness(0.94);
}

.card:active::after {
  animation: ripple-wave 600ms ease-out;
}

.card:focus-visible {
  outline: 3px solid #2f6df6;
  outline-offset: 3px;
}

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

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

@keyframes tap-loop {
  0%, 20% {
    transform: scale(1);
    filter: brightness(1);
  }
  50%, 70% {
    transform: scale(0.98);
    filter: brightness(0.94);
  }
  100% {
    transform: scale(1);
    filter: brightness(1);
  }
}
@keyframes ripple-wave {
  0% {
    box-shadow: inset 0 0 0 0 rgba(47, 109, 246, 0.62), inset 0 0 0 0 rgba(47, 109, 246, 0.45);
    opacity: 1;
  }
  16% {
    box-shadow: inset 0 0 0 5px rgba(47, 109, 246, 0.62), inset 0 0 0 2px rgba(47, 109, 246, 0.45);
    opacity: 1;
  }
  48% {
    box-shadow: inset 0 0 0 8px rgba(47, 109, 246, 0.55), inset 0 0 0 5px rgba(47, 109, 246, 0.4);
    opacity: 1;
  }
  56% {
    box-shadow: inset 0 0 0 9px rgba(47, 109, 246, 0), inset 0 0 0 6px rgba(47, 109, 246, 0);
    opacity: 0;
  }
  100% {
    box-shadow: inset 0 0 0 9px rgba(47, 109, 246, 0), inset 0 0 0 6px rgba(47, 109, 246, 0);
    opacity: 0;
  }
}
@keyframes ripple-loop {
  0%, 40% {
    box-shadow: inset 0 0 0 0 rgba(47, 109, 246, 0.62), inset 0 0 0 0 rgba(47, 109, 246, 0.45);
    opacity: 1;
  }
  46% {
    box-shadow: inset 0 0 0 5px rgba(47, 109, 246, 0.62), inset 0 0 0 2px rgba(47, 109, 246, 0.45);
    opacity: 1;
  }
  62% {
    box-shadow: inset 0 0 0 8px rgba(47, 109, 246, 0.55), inset 0 0 0 5px rgba(47, 109, 246, 0.4);
    opacity: 1;
  }
  68% {
    box-shadow: inset 0 0 0 9px rgba(47, 109, 246, 0), inset 0 0 0 6px rgba(47, 109, 246, 0);
    opacity: 0;
  }
  74%, 100% {
    box-shadow: inset 0 0 0 9px rgba(47, 109, 246, 0), inset 0 0 0 6px rgba(47, 109, 246, 0);
    opacity: 0;
  }
}
@media (prefers-reduced-motion: reduce) {
  .card {
    transition: none;
  }
  .card::after {
    animation: none !important;
    opacity: 0;
  }
  .card.is-demo {
    animation: none;
  }
}