This is fairly old but I just came accross it. I just wanted to add that I have experience with CSS::Parser: I wrote it. And I can tell you one thing about it, it s**ks real bad :(
However, I've now released CSS::SAC, the next generation replacement which I hope is much better (I've also removed CSS::Parser from CPAN). If you still need to do some CSS parsing, that would be the thing to try. I'd be happy to help, and it definitely needs people to bang on it (the folk from www-style have already started, but there's never enough :)
-- darobin -- knowscape 2 coming soon --