.hej::before {
    content: '';
    position: fixed;
    z-index: -1;
    display: block;
    top: 0px;
    left: 0px;
    bottom: 0px;
    right: 0px;
    background-image: url('assets/bildur.webp');
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center center;
}