@techee thanks so much for your effort, but I see you're planning to close this out once your work is merged and the reason I came here is that I need highlighting support for .**SASS**, _not_ .SCSS.
I use SASS which is indentation-based, and I use a lot of its shorthand properties (like = instead of @mixin). Gedit has this but I don't know how easy it is to port this to Geany. I would be willing to work with you to extend support to SASS, if you were interested.