Playground

<button class="switch" role="switch" aria-checked="false">  <span class="visually-hidden">Preview switch</span></button>

/* The state is reflected into the switch's aria-checked attribute. */.switch {  --on: state(false, bind(aria-checked));  background: when(--on, #f2542d, #d9d5cf);  transition: background 200ms;}.switch:on(click) {  --on: toggle();}