.jarallax {
     position: relative;
     z-index: 0;
 }
 .jarallax > .jarallax-img {
     position: absolute;
     object-fit: cover;
     /* support for plugin https://github.com/bfred-it/object-fit-images */
     font-family: 'object-fit: cover;';
     top: 0;
     left: 0;
     width: 100%;
     height: 100%;
     z-index: -1;
 }