.jarallax {
    position: relative;
    z-index: 0;
    background-color: #000;
}
.jarallax > .jarallax-img {
    position: absolute;
    object-fit: contain !important;
    top: 0;
    left: 0;
    width: auto !important;
    height: 100% !important;
    z-index: -1;
}

@media screen and (max-width: 768px) {
    .jarallax {
        height: 100vh !important;
    }
    .jarallax > .jarallax-img {
        width: 100% !important;
        height: 100% !important;
        object-fit: cover !important;
    }
}