Adobe Contribute users can’t make changes to a CSS style sheet. To change a style sheet for a Contribute site, use Dreamweaver.
The following are important factors to keep in mind when updating style sheets for a Contribute site:
If you make changes to a style sheet while a Contribute user is editing a page that uses that style sheet, the user won’t see the changes to the style sheet until they publish the page.
If you delete a style from a style sheet, the style name is not deleted from pages that use that style sheet, but since the style no longer exists, it isn’t displayed the way the Contribute user may expect. Thus, if a user tells you that nothing happens when they apply a particular style, the problem may be that the style has been deleted from the style sheet.