.zoom {
    background-position: 50% 50%;
    background-repeat: no-repeat;
    max-height: 100%;
    max-width: 100%;
}
.zoom img:not(.main) {
    display: block;
    margin: auto;
}
.zoom.eventHover:hover img {
    opacity: 0;
}

.zoom.zoomActive img {
    opacity: 0;
}