div.container {
    width: 620px;
    height: 398px;
    position: relative;
    margin: 0px;
}

div.image {
    height: 100%;
    background-repeat: no-repeat;
    background-position: top left;
    background-size: cover;
    position: absolute;
    top: 0px;
    left: 0px;
}

div.before {
    width: 50%;
    z-index: 2;
}

div.after {
    width: 100%;
    z-index: 1;
}

input.slider {
    width: 100%;
    height: 100%;
    outline: none;
    background-color: transparent;
    position: absolute;
    margin: 0px;
    z-index: 3;
    cursor: pointer;
    appearance: none;
    -moz-appearance: none;
    -webkit-appearance: none;
    transition: 0.25s all ease-in-out;
    -moz-transition: 0.25s all ease-in-out;
    -webkit-transition: 0.25s all ease-in-out;
    z-index: 4;
}

input.slider::-moz-range-thumb {
    width: 6px;
    height: 418px;
    background-color: white;
    cursor: pointer;
}

input.slider::-webkit-slider-thumb {
    width: 6px;
    height: 418px;
    background-color: white;
    cursor: pointer;
    appearance: none;
    -moz-appearance: none;
    -webkit-appearance: none;
}

div.slider-button {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    -moz-broder-radius: 50%;
    -webkit-border-radius: 50%;
    background-color: white;
    position: absolute;
    top: calc(50% - 18px);
    left: calc(50% - 18px);
    cursor: pointer;
    z-index: 3;
}

div.slider-button:before {
    color: #555;
    position: absolute;
    top: 3px;
    left: 0px;
    content: "\2B9C";
}

div.slider-button:after {
    color: #555;
    position: absolute;
    top: 3px;
    right: 0px;
    content: "\2B9E";
}

@media (max-width: 767px) {
    div.container {
        width: 100%;
        height: 398px;
    }
}