[MorenoArdohain]

Problem je sto taj tvoj client hosting fura Zeus server, koji inace servira css files kao text/plain..

Gecko is a standards-compliant rendering engine. When the server says a
css file is text/plain, that's how Gecko treats it. Gecko requires the
file type be text/css if you want it to treat it as css. Fix the broken
server, and Gecko will render it according to the standards.