.fullsize-wrapper {

    display: none;
    
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    
    z-index: 500;
}

.fullsize-wrapper-image {
    
    background: url(#) no-repeat center center fixed;
    background-size: contain;
    z-index: 501;
    
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}