div#comparison {
    width: 300px;
    height: 400px;
    max-width: 300px;
    max-height: 400px;
    overflow: hidden; }
div#comparison figure {
    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-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(255,255,255,0.5);
    width: 102%;
    color: red;
}
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);
}