I've just installed Linux Mint 17.2 (Raffaela) KDE. I am experiencing a strange problem with Firefox though: The Firefox controls (toolbar, bookmarks, tabs, etc.) in Firefox look huge compared to the rest of the KDE environment, and I haven't found a way to change that. Also, the page rendering looks weird, but at least that's changeable using the zoom functionality of Firefox. I have a suspicion that it's related to the fact that I'm using the Nvidia proprietary driver (nouveau does not work with my graphics card, which is a known issue). Does anybody know how I can fix that?
I've attached a screenshot which illustrates the issue.