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);
}

.kb {
  box-sizing: border-box;
  width: min(216px, 84vw);
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  color: #17141a;
}

.kb__label {
  display: block;
  font-size: 10px;
  line-height: 12px;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: rgba(23, 20, 26, 0.72);
  margin: 0 0 4px;
}

.kb__panel {
  position: relative;
  box-sizing: border-box;
  padding: 4px;
  background: #fff;
  border-radius: 16px;
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}

.kb__rail {
  position: absolute;
  top: 4px;
  left: 4px;
  right: 4px;
  height: 28px;
  border-radius: 8px;
  background: rgba(47, 109, 246, 0.14);
  box-shadow: inset 0 0 0 1px rgba(47, 109, 246, 0.35);
  transform: translateY(0);
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.kb__list {
  margin: 0;
  padding: 0;
  list-style: none;
  position: relative;
}

.kb__list:focus-visible {
  outline: 2px solid #2f6df6;
  outline-offset: 4px;
  border-radius: 8px;
}

.kb__opt {
  box-sizing: border-box;
  height: 28px;
  display: flex;
  align-items: center;
  padding: 0 8px;
  font-size: 12px;
  font-weight: 600;
  color: rgba(23, 20, 26, 0.7);
  cursor: pointer;
}

.kb__opt.is-at {
  color: #2f6df6;
}

.kb__opt.is-sel {
  font-weight: 800;
}

.kb__hint {
  display: block;
  margin: 8px 0 0;
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: rgba(23, 20, 26, 0.72);
}

.kb.is-demo .kb__rail {
  animation: kb-rail 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes kb-rail {
  0% {
    transform: translateY(0);
  }
  17% {
    transform: translateY(28px);
  }
  34% {
    transform: translateY(56px);
  }
  50% {
    transform: translateY(84px);
  }
  67% {
    transform: translateY(56px);
  }
  84% {
    transform: translateY(28px);
  }
  100% {
    transform: translateY(0);
  }
}
@media (prefers-reduced-motion: reduce) {
  .kb.is-demo .kb__rail {
    animation: none !important;
  }
  .kb__rail {
    transition: none;
  }
}