.imageoverlay {
            /* prevent text selection on overlay */
            -webkit-touch-callout: none;
            -webkit-user-select: none;
            -khtml-user-select: none;
            -moz-user-select: none;
            -ms-user-select: none;
            user-select: none;

            /* ignore pointer event on overlay */
            pointer-events: none;
        }