.jarallax {
    position: relative;
    z-index: 0;
}
.jarallax .jarallax-img {

    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background-position: center !important;
    background-size: cover !important;
}