.css-slideshow:after {
  position: fixed;
  width: 100%;
  height: 100%;
  top: 0px;
  left: 0px;
  z-index: 10;
  content: '';
  background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAYAAABytg0kAAAAFUlEQVQIHWNgYGB4/P//fwZGEAECAEVMBt9tNvSUAAAAAElFTkSuQmCC);
}