How do I change the fontsize for usernames on the post bit?
 

I've looked everywhere and I can't figure out where to change the font size. I don't want to use HTML code. I was hoping it would be in stylevars somewhere.

Can anyone help me? I want to make it bigger (no pun intended).

Under the StyleVars for your template is the Common section and in there is Font. If changing that doesn't work then find the postbit.css template and look for (I'm using legacy style postbit)

.postbitlegacy .userinfo a.username, .eventbit .userinfo a.username {
clear:{vb:stylevar right};
font-size:{vb:stylevar font.fontSize}{vb:stylevar font.units};
font-weight:bold;
width: auto;
max-width:{vb:math {vb:stylevar postbitlegacy_userinfo_width} - {vb:math {vb:stylevar padding}*2} - 20px};
word-wrap:break-word;
}

and you can change the font size manually there.