Where do you *envision this documentation existing?
I suppose that just comments in the css files would do or is there a different plan?
No, I'm not talking about documenting the css files but the classes used by the templates.
The documentation would have a dual role: as a guide to CSS authors as to how to develop new css-based themes and secondly as a guide to Template authors as to what reusable classes they should use (where appropriate)
Maybe a good start would be doc/CSS.txt to just document all of the CSS classes and what files they reside in. I started something here:
http://github.com/skyl/pinax/blob/53ccd9cef41d4100c576d84950022acc4c9d32f0/docs/CSS.txt
or is this not at all helpful?
That page doesn't exist!