div.container {
    width: 700px;
    height: 530px;
    position: relative;
    margin: 20px;
}

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: 600px;
        background-color: white;
        cursor: pointer;
    }

    input.slider::-webkit-slider-thumb {
        width: 6px;
        height: 530px;
        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: 250px;
    }
}