MediaWiki:Common.css/.page-Ybooh
/* CSS placed here will be applied to all skins */
body::before {
content: ; position: fixed; top: 0; left: 0; width: 100%; height: 100vh; background: #cccccc; background-attachment: fixed; background-position: center; background-repeat: no-repeat; background-size: cover; z-index: -1;
}