When you’ll be creating more than one RoboHelp project, either maintained directly in RoboHelp or with content linked from FrameMaker and other sources, consider keeping a CSS with a separate name other than default.css or RHStylemapping.css for use in your projects. A separate custom CSS will allow you to, among other things, put in code that addresses limitations or omissions in the standard CSS files (see http://wp.me/pKaGh-K)
When your custom CSS has a custom name, it will be easier to avoid confusion than if you simply overwrite one of the default CSS.
