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);
}

.panel {
  width: 100%;
  max-width: 340px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  text-align: center;
}

.title {
  margin: 0;
  color: #fff7e6;
  font-weight: 600;
  font-size: 15px;
}

.digitGroup {
  display: flex;
  gap: 8px;
}

.digitBox {
  width: 36px;
  height: 44px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: rgba(255, 247, 230, 0.08);
  border: 1px solid rgba(255, 247, 230, 0.24);
  color: #fff7e6;
  font-weight: 700;
  font-size: 18px;
  transition: border-color 220ms ease-out, background 220ms ease-out;
}

.digitBox.filled {
  border-color: #0a4fe8;
  background: rgba(10, 79, 232, 0.22);
}

.srOnly {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.submit {
  padding: 8px 32px;
  border: 0;
  border-radius: 12px;
  background: #0a4fe8;
  color: #fff7e6;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
}

.submit:disabled {
  cursor: not-allowed;
}

.hint {
  margin: 0;
  color: #fff7e6;
  opacity: 0.72;
  font-weight: 400;
  font-size: 12px;
}

@media (max-width: 340px) {
  .panel {
    max-width: 280px;
    gap: 12px;
  }
  .digitBox {
    width: 30px;
    height: 38px;
    font-size: 16px;
  }
  .submit {
    padding: 8px 24px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .digitBox {
    transition: none;
  }
}