Modifying css elements

[Marshall Neill <ramien43 windstream net>]

Hello everyone,
Just signed up and already I have a question.
I have modified the following gnome-shell.css
/* Copyright 2009, Red Hat, Inc.
 *
 * Portions adapted from Mx's data/style/default.css
 *   Copyright 2009 Intel Corporation

It's called the Ambiance theme.
I have modified it drastically, hey, I'm learning, but I got stuck, at 
least for now, on how to change the
color of the 'expanded' recent documents.
I have searched up and down the web and the entire gnome-theme.css file.
No luck whatsoever.  I would like to have it display as a grey 
gradient.  Light to dark.

Just a note, it would be real helpful if there was a PDF or an online 
document on some, if not all, of the elements
in the .css file.

Thanks in advance for any help.
Regards,
Marshall Neill