MediaWiki:Common.css is a Cascading Style Sheet loaded after the active Skin's stylesheet. This stylesheet is loaded with all {{ll|Help:Skins|skins}} and a similar stylesheet specific to the skin – named "{{tmpl|0=MediaWiki:skinname.css|skinname}}" – is appended to it (see below). Although only Monobook.css is listed on Special:AllMessages, the other skin-specific stylesheets will work nonetheless.
If $wgAllowUserCss is set to true, users can customize the interface for themselves only by creating user subpages with lowercase titles (see below).
Global stylesheets won't load on special restricted pages like login or preferences, unless you enable $wgAllowSiteCSSOnRestrictedPages.
List of stylesheets
Global stylesheets
These are stylesheets that affect all users of the wiki, depending on their setup — what skin they use, their user group, etc.
- MediaWiki:Common.css - all skins and all the users, except for the MobileFrontend
- MediaWiki:skinname.css - per skin, skinname is the value of that variable in the PHP file of your skin, for example MediaWiki:Vector.css, MediaWiki:Monobook.css
- User group CSS - per user group, for example MediaWiki:Group-sysop.css
- MediaWiki:Noscript.css - for users viewing without JavaScript; may be replaced with a
body.client-nojsselector - MediaWiki:Print.css - for "printable versions" of pages
- MediaWiki:Mobile.css - for Mobile themes, used with Extension:MobileFrontend
- MediaWiki:Filepage.css - specifically targeted to have Commons file pages (foreign repositories) work on 'local' file pages.
Personal stylesheets
These are stylesheets that only yourself and users with the editusercss right, usually interface admins, can edit.
- User:Example/common.css - all skins - introduced in MW v1.17
- User:Example/skinname.css - per skin, for example User:Example/vector.css and User:Example/monobook.css
- User:Example/global.css - per wiki family, if Extension:GlobalCssJs is in use in for this family