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);
}

.btn {
  border: 0;
  border-radius: 12px;
  padding: clamp(14px, 5vw, 22px) clamp(28px, 9vw, 56px);
  font-weight: 700;
  font-size: clamp(15px, 4.4vw, 20px);
  line-height: 1;
  font-family: inherit;
  color: #fff7e6;
  background: #2f6df6;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transform: scale(1);
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.btn:active {
  transform: scale(0.96);
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}
.btn.is-demo {
  animation: press-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes press-loop {
  0%, 12% {
    transform: scale(1);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  }
  22% {
    transform: scale(0.96);
    box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  }
  38%, 100% {
    transform: scale(1);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  }
}
@media (prefers-reduced-motion: reduce) {
  .btn {
    transition: none;
  }
  .btn.is-demo {
    animation: none;
  }
  .btn:active {
    transform: none;
    box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  }
}