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

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

.sw {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
}

.sw__input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.sw__track {
  position: relative;
  flex: 0 0 auto;
  width: 52px;
  height: 30px;
  box-sizing: border-box;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.1);
  border: 1px solid rgba(23, 20, 26, 0.22);
  backdrop-filter: blur(10px) saturate(160%);
  -webkit-backdrop-filter: blur(10px) saturate(160%);
  box-shadow: 0 2px 6px rgba(23, 20, 26, 0.18);
}

.sw__knob {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(23, 20, 26, 0.14);
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  transform: translateX(0);
  transition: transform 300ms cubic-bezier(0.2, 0.8, 0.2, 1), box-shadow 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.sw__label {
  color: #17141a;
  font: 600 12px/1 -apple-system, "Segoe UI", sans-serif;
}

.sw__input:checked ~ .sw__track .sw__knob {
  transform: translateX(22px);
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
}

.sw__input:checked ~ .sw__track {
  background: rgba(47, 109, 246, 0.55);
}

@keyframes sw-knob-loop {
  0%, 20% {
    transform: translateX(0);
    box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  }
  50%, 70% {
    transform: translateX(22px);
    box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  }
  100% {
    transform: translateX(0);
    box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
  }
}
.sw.is-demo .sw__knob {
  animation: sw-knob-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@media (prefers-reduced-motion: reduce) {
  .sw__knob {
    transition: none;
  }
  .sw.is-demo .sw__knob {
    animation: none !important;
  }
}