Do not use ResourceModuleSkinStyles to define skinStyles for other skins than 'minerva'
ResourceModuleSkinStyles must only contain customizations for the
skin that is defining it: in this case, 'minerva'. For other skins,
just use 'skinStyles' in module definition. Otherwise their own
customizations get overridden (or our customizations get overridden
by theirs, depending on the loading order).
MobileFrontend owns both of the wrongly customized modules
(mobile.special.history.styles and mobile.special.mobilemenu.styles).
Both have no need to be skinStyles.
- The mobile.special.mobilemenu.styles is an abandoned experiment in
Vector and the default stylesheet is Minerva specific.
- mobile.special.history.styles is not overriden by any skin so can
be registered as a stylesheet