Neumorphic

<input type="checkbox">

input {
  --s: 100px; /* control the size */
  --d: .7s; /* the transition duration */
  
  height: var(--s);
  border: calc(var(--s)/10) solid #0000;
  box-sizing: content-box;
  aspect-ratio: 2.2;
  border-radius: var(--s);
  background: #313b45;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  cursor: pointer;
  transition: .3s;
  position: relative;
  transition: var(--d);
  outline-offset: 5px;
}
input:before {
  content:"";
  position: absolute;
  top: 0;
  left: 0;
  width: var(--s);
  aspect-ratio: 1;
  border-radius: 50%;
  background: #fe5945;
  transition: 
    var(--d),
    top  cubic-bezier(.1,3000,.9,-3000) var(--d),
    left cubic-bezier(.5,3000,.5,-3000) 
     calc(4*var(--d)/5) calc(var(--d)/5);
}
input:checked:before {
  top:.2px;
  left:.3px;
  transform: translate(120%);
  background: #27c86a;
}
input:checked {
  transform: rotate(1turn);
}
body {
  margin:0;
  height:100vh;
  display:grid;
  grid-auto-flow :column;
  place-content: center;
  align-items:center;
  gap: 40px;
}

window.addEventListener('load', () => {
  let message = 'Hello, Runstant!';
  console.log(message);
});