Thanks Ruben! I've managed to get my styles working again, I just now need to change permissions on everything else that failed.
And it was pretty much everything else that failed - all sections except three. That's a LOT of files I have to CHMOD.
I haven't touched the files in a month or two, BUT the site was moved from shared hosting to a VPS. I'm thinking this must be when the permissions got screwed up.
I'll get changing and checking...
Thanks for your help!
Cheers,
Cerise.