You can include custom CSS and JavaScript that solely applies to the Chat feature.

Modifying chat for all users

Custom CSS for chat can be applied using MediaWiki:Chat.css. Custom JavaScript can be added using MediaWiki:Chat.js.

As with any community-wide CSS and JavaScript additions, they must abide by FANDOM's policy on allowed customizations and the Terms of Use.

Note: Editing of community JS pages requires JavaScript review process being enabled on your community.

Personal changes

You can add CSS and JS to your personal JS locally on individual communities via chat.css and chat.js, or globally via global.css (on Community Central). (Note: global.js is not currently active in Chat.)