Increase Font Size

I am helping a friend with their web site. This is an older audience and he needs the default font size to be larger. We are using WeaverX-treme theme and have set the font size in all areas to be either Medium or Large but none of those settings impacts the size of the font in the Forums table. Is this possible for us to change? I even tried to insert custom CSS for the class= bbpress-forums and had no luck.

The page I need help with: [log in to see the link]