html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffffff;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.btn {
  border: 2.5px solid #c2361a;
  border-radius: 14px;
  padding: 20px 40px;
  font: 800 20px/1 inherit;
  color: #c2361a;
  background: #ffe0d8;
  cursor: pointer;
}
.btn.is-shaking {
  animation: shake 420ms cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
}
.btn.is-demo {
  animation: shake-loop 2s cubic-bezier(0.36, 0.07, 0.19, 0.97) infinite;
}

@keyframes shake {
  10%, 90% {
    transform: translateX(-3px);
  }
  20%, 80% {
    transform: translateX(6px);
  }
  30%, 70% {
    transform: translateX(-6px);
  }
  40%, 60% {
    transform: translateX(4.2px);
  }
  50% {
    transform: translateX(-4.2px);
  }
}
@keyframes shake-loop {
  0%, 60% {
    transform: translateX(0);
  }
  62%, 78% {
    transform: translateX(-3px);
  }
  64%, 76% {
    transform: translateX(6px);
  }
  66%, 74% {
    transform: translateX(-6px);
  }
  68%, 72% {
    transform: translateX(4.2px);
  }
  70% {
    transform: translateX(-4.2px);
  }
  80%, 100% {
    transform: translateX(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .btn.is-shaking, .btn.is-demo {
    animation: none;
  }
  .btn.is-shaking {
    background: #c2361a;
    color: #fff;
  }
}