MediaWiki:Common.css

/* CSS placed here will be applied to all skins */
body {
    background-image: url('/skins/Vector/resources/images/pt_viewer_background.png');
    background-repeat: no-repeat;
}/*
body #mw-head {
    background-color: transparent;
}*/
#mw-page-base {
  background-image: none;
  background-color: transparent;
}