Need Help Formatting My Menu, Should Be a Quick Fix

I would ask on the theme’s forum, but I think they’ll ask me to pay first, and I think they should have made this information available in the first place.

I have been trying everything to change the text size and weight of the submenu on http://littlesingers.info.

I’m not a whiz at CSS, but I have tried various options and nothing has worked. If anyone can give me some help I would would appreciate it very much!