In the documentation, two different names for a css file are given, in order to override the css for guidedtours. I tried both, and neither work. Does anyone know what the name of the file should be? The pages I created are MediaWiki:Guidededtour-custom.css and MediaWiki:GuidedTour/custom.css.
Topic on Extension talk:GuidedTour/Archive2
@AmieH, according to the documentation it should be `MediaWiki:GuidedTour/custom.css`.
GuidedTours stopped loading the MediaWiki:GuidedTour/custom.css page as CSS in late 2014 (see https://gerrit.wikimedia.org/r/c/mediawiki/extensions/GuidedTour/+/165977 and https://gerrit.wikimedia.org/r/c/mediawiki/extensions/GuidedTour/+/164585 for detail). I'll update the documentation momentarily. You should be able to add the same styles to MediaWiki:Common.css though.