[eluser]Krystian[/eluser]
I`m always looking for such a problem like this: (I`m using Chrome )
1. ctrl+u to view page source
2. then you can click on the link which should provide you to the css file -> should occur in new tab
3. if not you have wrong path to it
if you refer to css file like href=”/css/cupertino/jquery-ui.css”
you should have proper entry in htaccess and of course use base_url()
so, href=”<?php echo base_url(); ?>css/cupertino/jquery-ui.css”