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);
}

.ss-stack {
  position: relative;
  width: 150px;
  height: 92px;
  perspective: 700px;
}

.ss-card {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: #fff7e6;
  color: #17141a;
  font: 700 16px/1 -apple-system, "Segoe UI", sans-serif;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  transform-style: preserve-3d;
}

.ss-card--2 {
  transform: translateZ(-16px) translateY(8px);
  opacity: 0.85;
}

.ss-card--3 {
  transform: translateZ(-32px) translateY(16px);
  opacity: 0.65;
}

@keyframes ss-shuffle {
  0%, 30% {
    transform: translateZ(0) translateX(0) rotateY(0);
    opacity: 1;
  }
  70% {
    transform: translateZ(-8px) translateX(-46px) rotateY(-150deg);
    opacity: 0.25;
  }
  71%, 100% {
    transform: translateZ(0) translateX(0) rotateY(0);
    opacity: 1;
  }
}
.ss-stack.is-demo .ss-card--1 {
  z-index: 3;
  animation: ss-shuffle 1800ms cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@media (prefers-reduced-motion: reduce) {
  .ss-stack.is-demo .ss-card--1 {
    animation: none !important;
    transform: none !important;
  }
}