[Plugin: TinyMCE Advanced] Body font overriden?

I’m having a heck of a time getting the body font of the editor to use my font styles – when I set an h1 or and h2 style, those work just fine, but I can’t seem to get just plain body text to display in the editor as anything other than the wordpress standard serifed font. Is there another stylesheet hiding somewhere that is overriding my body a and p tag editor styles?