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 {
  width: clamp(150px, 46vw, 180px);
  height: clamp(110px, 40vw, 140px);
  perspective: 900px;
}

.card__inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  animation: flip 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.card__face {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  gap: 8px;
  border-radius: 16px;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  backface-visibility: hidden;
}

.card__face--front {
  background: #fff7e6;
  color: #17141a;
}

.card__face--back {
  background: #17141a;
  color: #fff7e6;
  transform: rotateY(180deg);
}

.card__icon {
  width: 30px;
  height: 30px;
  border-radius: 50%;
}

.card__icon--sun {
  background: #ffd23f;
}

.card__icon--moon {
  background: #fff7e6;
}

.card__label {
  margin: 0;
  font-weight: 600;
  font-size: clamp(11px, 3.2vw, 13px);
  line-height: 1;
  font-family: inherit;
}

@keyframes flip {
  0%, 15% {
    transform: rotateY(0deg);
  }
  50% {
    transform: rotateY(180deg);
  }
  85%, 100% {
    transform: rotateY(360deg);
  }
}
@media (prefers-reduced-motion: reduce) {
  .card__inner {
    animation: none !important;
    transform: rotateY(0deg);
  }
}