.jarallax-img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;

    /*
    iOS Safari has long-standing bugs with negative z-index inside positioned parents, especially when:
    - parent has position: absolute
    - siblings use z-index
    - transforms/parallax are involved
    */
    z-index: 0;
}