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);
}

.bi-a {
  display: flex;
  flex-direction: column;
  gap: 16px;
  width: clamp(220px, 78vw, 320px);
}

.bi-a__input {
  border: 0;
  border-radius: 12px;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.06);
  color: #ffffff;
  font: 500 clamp(12px, 3vw, 13.5px)/1.3 -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  box-shadow: 0 0 0 2px rgba(47, 109, 246, 0.55), 0 0 16px rgba(255, 77, 31, 0.45);
}

.bi-a__input::placeholder {
  color: rgba(255, 255, 255, 0.4);
}

.bi-a__btn {
  align-self: flex-start;
  border: 0;
  border-radius: 12px;
  padding: 12px 24px;
  color: #17141a;
  font-weight: 700;
  font-size: clamp(12px, 3vw, 13.5px);
  line-height: 1;
  background: linear-gradient(120deg, #ffd23f, #ff4d1f, #2f6df6, #ffd23f);
  background-size: 260% 100%;
  background-position: 0% 50%;
}

.is-demo .bi-a__btn,
.bi-a__btn:hover,
.bi-a__btn:focus-visible {
  animation: shift 2s ease-out infinite;
}

@keyframes shift {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}
@media (prefers-reduced-motion: reduce) {
  .is-demo .bi-a__btn, .bi-a__btn:hover, .bi-a__btn:focus-visible {
    animation: none;
  }
}