to start: it's definitely not my custom CSS.

here's a screenshot - note that the text in the sidebar is fine until chookie's second comment in the friend feed, where everything becomes italicized. here is what inspect element shows in my FF. the full comment is here. every page i've been on so far has been affected. removing the friend feed from the sidebar fixes the problem, but when i put it back the italics returned.

i'm using firefox, version 58.0.2 (64-bit)