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);
}

.btn {
  box-sizing: border-box;
  position: relative;
  width: 240px;
  height: 64px;
  border: none;
  border-radius: 12px;
  background: #17141a;
  color: #fff7e6;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  font-weight: 700;
  font-size: 17px;
  cursor: pointer;
  overflow: hidden;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}

.btn__label {
  position: relative;
  z-index: 1;
}

.btn::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: -60%;
  width: 60%;
  background: linear-gradient(115deg, transparent 0%, rgba(255, 255, 255, 0.85) 50%, transparent 100%);
  transform: skewX(-20deg) translateX(-10%);
}

.btn:hover::after {
  animation: sweep 600ms ease-out 1;
}

.btn:focus-visible {
  outline: 3px solid #17141a;
  outline-offset: 4px;
}

.stage.is-demo .btn::after {
  animation: sweep 2s ease-out infinite;
}

@keyframes sweep {
  0%, 10% {
    transform: skewX(-20deg) translateX(-10%);
  }
  55% {
    transform: skewX(-20deg) translateX(310%);
  }
  100% {
    transform: skewX(-20deg) translateX(310%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .btn:hover::after, .stage.is-demo .btn::after {
    animation: none;
    transform: skewX(-20deg) translateX(-10%);
  }
}