.loader {
    position: fixed;
    left: 0px;
    top: 0px;
    width: 100%;
    height: 100%;
    z-index: 9999;
    background: url('../../assets/images/system/pre-loader.gif') 50% 50% no-repeat #fff;
    background-size: 250px;
    /*opacity: 0.9;*/
}