Анимириваный css слайд - включить/выключить

<input type="checkbox">​

html {
  background-color: #e4ded4;
  background-image: -webkit-linear-gradient(hsla(0,0%,0%,.1), hsla(0,0%,100%,.1));
  box-shadow: inset 0 0 100px hsla(0,0%,0%,.1);
  height: 100%;
}
input[type="checkbox"] {
  background-image: -webkit-linear-gradient(hsla(0,0%,0%,.1), hsla(0,0%,100%,.1)),
  -webkit-linear-gradient(left, #f66 50%, #6cf 50%);
  background-size: 100% 100%, 200% 100%;
  background-position: 0 0, 15px 0;
  border-radius: 25px;
  box-shadow: inset 0 1px 4px hsla(0,0%,0%,.5),
  inset 0 0 10px hsla(0,0%,0%,.5),
  0 0 0 1px hsla(0,0%,0%,.1),
  0 -1px 2px 2px hsla(0,0%,0%,.25),
  0 2px 2px 2px hsla(0,0%,100%,.75);
  cursor: pointer;
  height: 25px;
  left: 50%;
  margin: -12px -37px;
  padding-right: 25px;
  position: absolute;
  top: 50%;
  width: 75px;
  -webkit-appearance: none;
  -webkit-transition: .25s;
}
input[type="checkbox"]:after {
  background-color: #eee;
  background-image: -webkit-linear-gradient(hsla(0,0%,100%,.1), hsla(0,0%,0%,.1));
  border-radius: 25px;
  box-shadow: inset 0 1px 1px 1px hsla(0,0%,100%,1),
  inset 0 -1px 1px 1px hsla(0,0%,0%,.25),
  0 1px 3px 1px hsla(0,0%,0%,.5),
  0 0 2px hsla(0,0%,0%,.25);
  content: '';
  display: block;
  height: 25px;
  left: 0;
  position: relative;
  top: 0;
  width: 50px;
}
input[type="checkbox"]:checked {
  background-position: 0 0, 35px 0;
  padding-left: 25px;
  padding-right: 0;
}
​