Before and after in one single HTML component

before-after.html

<div id="comparison">
  <figure>
    <div id="divisor"></div>
  </figure>
  <input type="range" min="0" max="100" value="50" id="slider" oninput="moveDivisor()">
</div>
<style>
  div#comparison { 
  width: 60vw;
  height: 60vw;
  max-width: 600px;
  max-height: 600px;
  overflow: hidden; }
div#comparison figure { 
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/4273/photoshop-face-before.jpg); 
  background-size: cover;
  position: relative;
  font-size: 0;
  width: 100%; 
  height: 100%;
  margin: 0; 
}
div#comparison figure > img { 
  position: relative;
  width: 100%;
}
div#comparison figure div { 
  background-image: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/4273/photoshop-face-after.jpg);
  background-size: cover;
  position: absolute;
  width: 50%; 
  box-shadow: 0 5px 10px -2px rgba(0,0,0,0.3);
  overflow: hidden;
  bottom: 0;
  height: 100%;
}

input[type=range]{
  -webkit-appearance:none;
  -moz-appearance:none;
  position: relative;
  top: -2rem; left: -2%;
  background-color: rgba(255,255,255,0.1);
  width: 102%; 
}
input[type=range]:focus { 
  outline: none; 
}
input[type=range]:active { 
  outline: none;  
}

input[type=range]::-moz-range-track { 
  -moz-appearance:none;
    height:15px;
    width: 98%;
    background-color: rgba(255,255,255,0.1); 
    position: relative;
    outline: none;    
 }
input[type=range]::active { 
  border: none; 
  outline: none;
}
input[type=range]::-webkit-slider-thumb {
    -webkit-appearance:none;
    width: 20px; height: 15px;   
    background: #fff;
    border-radius: 0;
   }
input[type=range]::-moz-range-thumb {
  -moz-appearance: none;
  width: 20px;
  height: 15px;
  background: #fff;
  border-radius: 0;
     }   
input[type=range]:focus::-webkit-slider-thumb {
    background: rgba(255,255,255,0.5);
   }
input[type=range]:focus::-moz-range-thumb {
    background: rgba(255,255,255,0.5);
   }
</style>
<script>
  var divisor = document.getElementById("divisor"),
slider = document.getElementById("slider");
function moveDivisor() { 
	divisor.style.width = slider.value+"%";
}
</script>