CSS loading overlay with a spinner

loading-overlay.css

/* *spinner image not included */

.loading {
    position: relative;
    pointer-events: none;
    cursor: not-allowed;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

.loading:after {
    position: absolute;
    content: '';
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255,255,255,0.5) url('../img/preloader.gif') no-repeat center center;
    z-index: 110;
}