At the time of this writing, there are no styles on programmers.stackexchange.com (or its meta site). Tried with multiple browsers on multiple computers.
This seems to be the case on all beta sites.
Recently we migrated to a new css framework (lesscss) we are still sorting out some kinks, should be fixed now
The Artificial Intelligence (private) beta is working fine at this time. Programmers is currently broke. I think this is related to the days visited calendar being broken on all sites.