prevElement = null;
document.addEventListener('mousemove',
function(e){
varelem = e.target || e.srcElement;
if (prevElement!= null) {prevElement.classList.remove("mouseOn");}
elem.classList.add("mouseOn");
prevElement = elem;
},true);
CSS code:
.mouseOn{
background-color: #bcd5eb !important;
outline: 2px solid #5166bb !important;
}