Górna warstwa elementu CSS
#overlayDiv {
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
z-index:99;
}
Borma
#overlayDiv {
position: fixed;
top: 0;
left: 0;
width: 100%;
height: 100%;
z-index:99;
}