How can I use CSS styling in my GTK# application? I heard before that it is impossible to use CSS themes in GTK#, but after that I found this example of using css styling in GTK#. Besides this I found also the samples of using CSS styling in Banshee project (which uses GTK#). So how is it possible? I already tried to do the same in GTK#, but I didn't find CssProvider class. So how I can find this class in GTK# or how I can using CSS styling in GTK#?