html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.cs {
  position: relative;
  width: min(200px, 78vw);
}

.cs__btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  border: 2px solid rgba(23, 20, 26, 0.4);
  border-radius: 12px;
  padding: 12px 16px;
  font-weight: 600;
  font-size: clamp(13px, 3.8vw, 15px);
  line-height: 1;
  font-family: inherit;
  color: #17141a;
  background: transparent;
  cursor: pointer;
}

.cs__chevron {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: #17141a;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transform: rotate(0deg);
  transition: transform 300ms cubic-bezier(0.3, 1.5, 0.4, 1);
}

.cs.is-open .cs__chevron {
  transform: rotate(180deg);
}

.cs__list {
  position: absolute;
  left: 0;
  right: 0;
  top: calc(100% + 8px);
  margin: 0;
  padding: 8px;
  list-style: none;
  border-radius: 12px;
  background: #fff7e6;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  transform: scaleY(0);
  transform-origin: top;
  opacity: 0;
  pointer-events: none;
  transition: transform 300ms cubic-bezier(0.3, 1.5, 0.4, 1), opacity 300ms cubic-bezier(0.3, 1.5, 0.4, 1);
}

.cs.is-open .cs__list {
  transform: scaleY(1);
  opacity: 1;
  pointer-events: auto;
}

.cs__bloom {
  position: absolute;
  left: 0;
  right: 0;
  top: calc(100% + 8px);
  height: 48px;
  background: radial-gradient(ellipse 70% 100% at 50% 0%, rgba(255, 247, 230, 0.35) 0%, rgba(255, 247, 230, 0) 70%);
  opacity: 0;
  pointer-events: none;
}

.cs.is-open .cs__bloom {
  animation: cs-bloom 300ms ease-out;
}

@keyframes cs-bloom {
  0% {
    opacity: 0;
    transform: scaleY(0.5);
  }
  40% {
    opacity: 1;
    transform: scaleY(1);
  }
  100% {
    opacity: 0;
    transform: scaleY(1.1);
  }
}
.cs__opt {
  padding: 8px 12px;
  border-radius: 8px;
  font-weight: 500;
  font-size: clamp(13px, 3.6vw, 14px);
  line-height: 1;
  font-family: inherit;
  color: #c93000;
}
.cs__opt:hover {
  background: rgba(255, 77, 31, 0.08);
}

@media (prefers-reduced-motion: reduce) {
  .cs__chevron, .cs__list {
    transition: none;
  }
  .cs.is-open .cs__bloom {
    animation: none;
  }
}