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);
}

.form {
  width: clamp(220px, 76vw, 320px);
  display: flex;
  flex-direction: column;
  gap: clamp(10px, 3vw, 14px);
}

.form__field {
  position: relative;
  display: block;
  border-radius: 12px;
  background: #fff7e6;
}

.form__ring {
  position: absolute;
  inset: -3px;
  border-radius: calc(12px + 3px);
  border: 2px solid #2f6df6;
  opacity: 0;
  animation: ringPulse 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.form__input {
  width: 100%;
  box-sizing: border-box;
  border: 0;
  border-radius: 12px;
  background: transparent;
  padding: clamp(11px, 3vw, 13px) clamp(14px, 3.6vw, 16px);
  color: #17141a;
  font-weight: 500;
  font-size: clamp(11px, 2.8vw, 13px);
  line-height: 1;
}

.form__input::placeholder {
  color: rgba(23, 20, 26, 0.45);
}

.form__btn {
  border: 0;
  border-radius: 12px;
  background: #0a4fe8;
  color: #fff7e6;
  padding: clamp(11px, 3vw, 13px);
  font-weight: 700;
  font-size: clamp(11px, 2.8vw, 13px);
  line-height: 1;
  animation: btnPress 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes ringPulse {
  0%, 20% {
    opacity: 0;
  }
  32%, 55% {
    opacity: 1;
  }
  68%, 100% {
    opacity: 0;
  }
}
@keyframes btnPress {
  0%, 68% {
    transform: scale(1);
  }
  78% {
    transform: scale(0.96);
  }
  88%, 100% {
    transform: scale(1);
  }
}
@media (prefers-reduced-motion: reduce) {
  .form__ring,
  .form__btn {
    animation: none !important;
    transform: none;
  }
  .form__ring {
    opacity: 0;
  }
}