Interface admins now have greater control over the styling of article components on mobile with the introduction of the SiteAdminHelper. More information on how styles can be disabled can be found at https://www.mediawiki.org/wiki/Extension:WikimediaMessages#Site_admin_helper.

More background

Wikimedia Foundation has been optimizing content such as infoboxes, ambox templates, main pages and hatnotes for mobile display. We received feedback that this was problematic on certain wikis where their markup was inconsistent with others. To support giving more control, system admins can now copy across styles they need to [[MediaWiki:Minerva.css]] / [[MediaWiki:Common.css]] or TemplateStyles and disable the Wikimedia Foundation provided styles.

If you have questions feel free to ask them here.