.locker {
    display: none;
    position: fixed;
    left: 0px;
    top: 0px;
    width: 100%;
    height: 100%;
    z-index: 9999;
    background: rgba(0,0,0,0.8); /*lets make it semi-transparent */
    z-index: 9999; /*because you could set some z-indexes in your code before, so lets make sure that this will be over every elements in html*/
    background: url('/MAssets/locker/EllipsisSpinner3.svg') 50% 50% no-repeat rgba(0,0,0,0.8);
}