.overlay {

  width:  100%;
  z-index: 10;
  display: block;
  position: absolute;
  height: 100%;
  top: 0;
  left: 0;
  right: 0;
/*  background: rgba(255, 255, 255, 0.8);*/
  background: rgba(0, 0, 0, 0.6);

  height: 100%;
}




.overlay > img {

   position: absolute;
   left: 50%;
   top: 50%; 
   margin-left: -150px;
   margin-top: -150px;
   
}