MediaWiki:Common.css

/* CSS placed here will be applied to all skins */
#image-box {
  position:center;
  background-image: url('https://static.wikiforge.net/sherlockwikitide/d/df/Sherlock-cast-i34913.jpg');
  background-repeat: no-repeat;
  height: 600px;
  width: 700px;
  background-size: 70%
}