.base {
  position:relative;
}

/* a transparent div overlaid on another div */

.base .overlay {
  content: " ";
  z-index: 10;
  display: block;
  position: absolute;
  height: 100%;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(0, 0, 0, 0);
  font-size:300%;
  line-height:65px;
  text-align:center;
  color: #80808040;
}