Customize Drop-down menu font?

Need help with customizing a BB Themer Header I created. I added my navigation as a Themer buildout because I needed to add some custom imagery.

I’ve figured out how to increase the padding of the box, but the font is wrapping around at a smaller width. Alternatively, I could always decrease the font size, but I only want to do this to the drop-down items. Not the main nav font. Help!