Category description on hover?

Hi,

when adding categories for various CPTs I sometimes have put text in the Description box for a category. I note that below the box it says: The description is not prominent by default; however, some themes may show it – I have not made use of this, but have now got a situation where I think it may be useful!

I have a long name for one of my categories – when it is displayed in the side box of the main map (where you can tick/untick the categories to be displayed on the map) it looks too long (and on a different line than tick box). I could abbreviate the category name, but this would mean it may not be understood by all. I wonder then if it is possible – at least for this one category – to have the abbreviated name on the map panel, but have the full name or a description (whatever I put in the Description box) pop up when the cursor hovers over the category name on the map side panel? I use GDF modern as my theme but can’t see any controls to achieve this – or is this something that might have to be done with CSS? (in which case any pointers greatly received.

Thanks