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);
}

.card {
  box-sizing: border-box;
  width: min(260px, 84vw);
  padding: 24px 24px;
  border-radius: 16px;
  background: #17141a;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  opacity: 0;
  transform: translateY(-32px);
}

.card__title {
  margin: 0 0 4px;
  color: #fff7e6;
  font-weight: 700;
  font-size: clamp(15px, 4vw, 18px);
  line-height: 1.3;
  font-family: inherit;
}

.card__sub {
  margin: 0;
  color: rgba(255, 247, 230, 0.7);
  font-weight: 400;
  font-size: clamp(13px, 3.4vw, 14px);
  line-height: 1.4;
  font-family: inherit;
}

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

@keyframes slide-in-loop {
  0% {
    opacity: 0;
    transform: translateY(-32px);
  }
  25% {
    opacity: 1;
    transform: translateY(0);
  }
  85% {
    opacity: 1;
    transform: translateY(0);
  }
  100% {
    opacity: 0;
    transform: translateY(-32px);
  }
}
.card.is-appear {
  animation: slide-in 500ms ease-out both;
}

@keyframes slide-in {
  from {
    opacity: 0;
    transform: translateY(-32px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .card.is-demo, .card.is-appear {
    animation: none;
    opacity: 1;
    transform: none;
  }
}