Having problems adding navbar to modified template

Site: http://colbertu.nofactzone.net

My site is running a modified version of the Red Rose theme (http://themes.wordpress.net/columns/2-columns/1394/red-rose-1/). I’ve got the site looking the way I want (or I can tweak it myself) in every way but one. I want to add a navbar between the main page header and the body text.

I tried adding a page with instructions from this page:
http://www.dontdream.it/en/2005/08/12/navigation-bar-howto/

But it doesn’t seem to be doing what I want it to be doing. I can’t get the site to see the formatting added in the style.css page.

Can anyone recommend a repair for this issue?