'aye, you can't quite use the rule names I used, but the a effect similar to it can be done with what you already have in-place.
I could work a version that's a copy of yours, with the changes that'd fix the resizing. (Stylish?)
Since I'm not exactly good at explaining, I believe a stylesheet to replace/add values to the original stylesheet should speak for itself.
E: Did you have a rule for *?
E:
http://pastebin.com/raw.php?i=JXvYKQfs Add this to Stylish (Mozilla, Chromium), make it apply to URL (
http://www.hiveworkshop.com/forums/chat.php) and save the stylesheet.
It's still a work in progress, but that's something you could use to test it.
Something to note:
The back button is behind other elements, and can't be pressed. (You can disable the stylesheet from Stylish once you've created it and applied it to the page)