.slider-before-after {
    position: relative;
}

.slider-before-image,
.slider-after-image {
    overflow: hidden;
    position: absolute;
    left: 0;
    top: 0;
}

.slider-after-image {
    will-change: width;
}

.slider-before-image img,
.slider-after-image img {
    /* Remove 5.6px of bottom space below image */
    float: left;
}