Hello,

I would like to have several pages using two different themes [red] and [blue] for example , but i would like to have a base.css file that can be shared by both without having to defined identical section in both of them.

To give you a better picture i would have the [red] theme folder with two css files : red.css and base.css . And the blue one with 2 css asd well : blue.css and base.css. is there any way i can define a global stylesheet to be used by both pages

for common sections without having to duplicate base.css?  I also noticed that in visual studio 2008 beta2, having two css files in the theme folder generated an error (The class or cssValue is not defined), although it doesn;t keep it to render itself correctly.

Is it a bad practice to have multiple css files for a theme?

Thanks 

Using multiple CSS files is a great idea, it facilitates reuse and maintainability. However; if you have a high traffic site (like an e-commerce site), you'll probably want to combine your CSS into a single file for better performance, but you would typically only do this on your production site.

If you want to have a CSS file that's inherited by other Style Sheets, then you'll probably have to move your Style Sheet outside the App_Theme directory and into a more general CSS directory. As you've pointed out (Themes promote CSS duplication), ASP.NET Themes provide an over simplistic approach to CSS, which hampers the use of Style Sheets.