One Pixel Error.
This a truly odd situation. We expect css to render differently in broken browsers (IE - on any platform, really), but Firefox is rendering with a one pixel error between Linux, Windows, and Mac. I think it might have something to do with the fonts in Linux though.
This is how the set of tabs is supposed to look, and it appears this way while using Firefox under Gentoo Linux.
This is how the set of tabs looks under Windows and Mac in Firefox. I adjusted the css to illustrate how it appears, versus taking a screenshot in Windows, so the fonts are the same, obviously, in this image.
It’s just one of those funny situations where I need to decide if I want it to look right for me, or for everyone else. ;) That is, unless I can fix it, which I’ll certainly attempt to do. I think I just need to totally rethink the implementation, bugger.