@BraveOtter
I don't know if you are still suffering your fat borders issue on Z15.2, which has gnome desktop.
I have just done a quick web search and found this:
https://stackoverflow.com/questions/474 ... gnome-3-26That was asking how to make windows borders wider, wheras you are looking to do the opposite. however default value for normal border width is mentioned.
I was also wondering if there was some variable you could adjust using Gnome Tweaks (See Swarfendor437's unofficial manual p105), but I think not.
If you have not looked at the manual it can be downloaded, see here:
viewtopic.php?f=5&t=14361