#block-block_templating-related_video .play_bttn {
  background: url("../images/play_bttn_video.png") no-repeat scroll center transparent;
  display: block;
  height: 100%;
  left: 0;
  position: absolute;
  top: 0;
  width: 100%;
  z-index: 100;
}

#block-block_templating-related_video a:hover .play_bttn {
  background: url("../images/play_bttn_video_hover.png") no-repeat scroll center transparent;
}