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);
}

.ck {
  width: 100%;
  max-width: 280px;
  display: grid;
  gap: 12px;
  justify-items: start;
}

.ck__field {
  display: block;
  width: 100%;
}

.ck__input {
  width: 100%;
  box-sizing: border-box;
  padding: 12px 16px;
  border-radius: 12px;
  border: 2px solid transparent;
  background: #17141a;
  color: #fff7e6;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-weight: 600;
  font-size: 16px;
  letter-spacing: 0.05em;
  transition: border-color 220ms ease-out;
}
.ck__input:focus {
  outline: 2px solid #17141a;
  outline-offset: 2px;
}

.ck__field--error {
  animation: ckShake 600ms ease-out;
}
.ck__field--error .ck__input {
  border-color: #c2361a;
}

@keyframes ckShake {
  0% {
    transform: translateX(0);
  }
  10% {
    transform: translateX(6.5px);
  }
  20% {
    transform: translateX(1.8px);
  }
  30% {
    transform: translateX(-3.1px);
  }
  40% {
    transform: translateX(-1.9px);
  }
  50% {
    transform: translateX(1.2px);
  }
  60% {
    transform: translateX(1.4px);
  }
  70% {
    transform: translateX(-0.3px);
  }
  80% {
    transform: translateX(-0.8px);
  }
  90% {
    transform: translateX(-0.1px);
  }
  100% {
    transform: translateX(0);
  }
}
.ck__btn {
  border: 0;
  border-radius: 999px;
  padding: 8px 24px;
  background: #17141a;
  color: #fff7e6;
  font-weight: 700;
  font-size: 13px;
  cursor: pointer;
  transition: transform 140ms ease-out;
}
.ck__btn:active {
  transform: scale(0.95);
}

.ck__msg {
  margin: 0;
  min-height: 16px;
  color: #17141a;
  font-weight: 700;
  font-size: 12px;
}

@media (max-width: 340px) {
  .ck__input {
    padding: 8px 12px;
    font-size: 14px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .ck__field--error {
    animation: none;
  }
  .ck__input {
    transition: none;
  }
}