.loading-overlay {
    position: fixed;
    width: 100%;
    height: 100%;
    z-index: 1000;
    top: 40%;
    left: 0px;
    opacity: 0.5;
    filter: alpha(opacity=50);
    display:none;
 }

 .dim {
    /* For Internet Explorer */
    box-shadow: 0 0 0 1000px rgba(0, 0, 0, .3);
      
    /* For other browsers */
    box-shadow: 0 0 0 100vmax rgba(0, 0, 0, .3);
}