Smooth Toggle Switch

<label class="tgl">
  <input type="checkbox" checked>
  <span class="tgl-slider"></span>
</label>

.tgl {
  position: relative;
  display: inline-block;
  width: 52px;
  height: 30px;
}
.tgl input { opacity: 0; width: 0; height: 0; }
.tgl-slider {
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0.15);
  border-radius: 9999px;
  transition: background .3s;
  cursor: pointer;
}
.tgl-slider::before {
  content: '';
  position: absolute;
  width: 24px;
  height: 24px;
  left: 3px;
  bottom: 3px;
  background: #fff;
  border-radius: 50%;
  transition: transform .3s cubic-bezier(.4,0,.2,1);
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}
.tgl input:checked + .tgl-slider { background: #a78bfa; }
.tgl input:checked + .tgl-slider::before { transform: translateX(22px); }