If by CSS you mean Cascading Style Sheets, then CSS isn't what you want.
There are some new technologies that might do what you are thinking. You can investigate XAML (Extensible Application Markup Language) with WPF (Windows Presentation Foundation). XAML is an XML based markup that works within WPF.
XAML syntax definines the UI for WPF and is used to separate the Presentaion mechanism from the application code behind it.