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

.stage {
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
}

.btn {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  border: 0;
  border-radius: 16px;
  padding: 3px;
  background: transparent;
  cursor: pointer;
}
.btn::before {
  content: "";
  position: absolute;
  inset: -60%;
  background: conic-gradient(from 0deg, #ff4d1f, #ffd23f, #2f6df6, #ff4d1f);
  animation: spin 3s linear infinite;
  z-index: -1;
}

.btn__in {
  display: block;
  border-radius: 13px;
  padding: 20px 52px;
  font: 800 20px/1 inherit;
  color: #fff7e6;
  background: #17141a;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}
@media (prefers-reduced-motion: reduce) {
  .btn::before {
    animation: none;
  }
}