.modal {
    display:    none;
    position:   fixed;
    z-index:    3000;
    top:        0;
    left:       0;
    height:     100%;
    width:      100%;    
    background-position: center center; 
    background-repeat: no-repeat;
    background-color: rgba( 255, 255, 255, .6 );
}
.loading {
    overflow: hidden;   
}
.loading .modal {
    display: block;
}