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);
}

.rm-card {
  position: relative;
  perspective: 700px;
  width: 170px;
  height: 108px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.rm-card__inner {
  position: relative;
  width: 170px;
  height: 92px;
  transform-style: preserve-3d;
}

.rm-card:hover .rm-card__inner {
  transform: rotateY(180deg);
  transition: transform 600ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.rm-card__face {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  backface-visibility: hidden;
  font: 700 14px/1 -apple-system, "Segoe UI", sans-serif;
  color: #fff7e6;
}

.rm-card__face--front {
  background: #0a4fe8;
}

.rm-card__face--back {
  background: rgba(255, 255, 255, 0.14);
  transform: rotateY(180deg);
}

.rm-tag {
  font: 600 10px/1 -apple-system, sans-serif;
  letter-spacing: 0.05em;
  color: #fff7e6;
  opacity: 0.6;
}

@keyframes rm-crossfade-front {
  0% {
    opacity: 1;
  }
  50% {
    opacity: 0;
  }
  100% {
    opacity: 1;
  }
}
@keyframes rm-crossfade-back {
  0% {
    opacity: 0;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0;
  }
}
.rm-card.is-demo .rm-card__inner {
  transform: none;
}

.rm-card.is-demo .rm-card__face--front {
  animation: rm-crossfade-front 1560ms ease-out infinite;
  backface-visibility: visible;
  transform: none;
}

.rm-card.is-demo .rm-card__face--back {
  animation: rm-crossfade-back 1560ms ease-out infinite;
  backface-visibility: visible;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .rm-card:hover .rm-card__inner {
    transform: none;
    transition: none;
  }
  .rm-card:hover .rm-card__face--front {
    opacity: 0;
    transition: opacity 300ms ease-out;
  }
  .rm-card:hover .rm-card__face--back {
    opacity: 1;
    transform: none;
    transition: opacity 300ms ease-out;
  }
}