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);
}

.sd {
  display: grid;
  justify-items: center;
}

.sd__shell {
  position: relative;
  width: 240px;
  height: 56px;
  cursor: pointer;
}

.sd__half {
  position: absolute;
  top: 0;
  width: calc(var(--shell-w, 240px) / 2);
  height: 100%;
  border-radius: 999px;
  background: #ffe0d8;
  transition: transform 600ms cubic-bezier(0.34, 1.56, 0.64, 1), background-color 220ms ease-out;
}
.sd__half--l {
  left: 0;
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
}
.sd__half--r {
  right: 0;
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

.sd__face {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.sd__face--rest {
  transition: opacity 220ms ease-out;
}

.sd__label {
  color: #c2361a;
  font-weight: 700;
  font-size: 16px;
}

.sd__face--split {
  opacity: 0;
  transition: opacity 220ms ease-out;
}

.sd__choice {
  border: 0;
  border-radius: 999px;
  background: #ffffff;
  color: #17141a;
  font-weight: 600;
  font-size: 13px;
  padding: 8px 16px;
  cursor: pointer;
}
.sd__choice--danger {
  background: #c2361a;
  color: #fff7e6;
}

.sd--split .sd__half--l {
  transform: translateX(-26px);
  background: #ffe0d8;
}
.sd--split .sd__half--r {
  transform: translateX(26px);
}
.sd--split .sd__face--rest {
  opacity: 0;
}
.sd--split .sd__face--split {
  opacity: 1;
}

@media (max-width: 340px) {
  .sd__shell {
    width: 210px;
    height: 52px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .sd__half, .sd__face--rest, .sd__face--split {
    transition: none;
  }
}