.zoom {
    -webkit-transition: all 0.35s ease-in-out;
    -moz-transition: all 0.35s ease-in-out;
    transition: all 0.35s ease-in-out;
    cursor: zoom-in;
}

.zoom:hover,
.zoom:active,
.zoom:focus {
    /**adjust scale to desired size,
    add browser prefixes**/
    -ms-transform: scale(2.5);
    -moz-transform: scale(2.5);
    -webkit-transform: scale(2.5);
    -o-transform: scale(2.5);
    transform: scale(2.5);
    position: relative;
    z-index: 100;
}

/**To keep upscaled images visible on mobile,
increase left & right margins a bit**/
@media only screen and (max-width: 768px) {
    ul.gallery {
        margin-left: 15vw;
        margin-right: 15vw;
    }

    /**TIP: Easy escape for touch screens,
    give gallery's parent container a cursor: pointer.**/
    .DivName {
        cursor: pointer
    }
}