There is nothing stopping you from inspecting with firebug or chrome montrealtweetup.com and looking at the .css and for that matter the .js or the html to see what is going on and how they do things. however, some things you might not find if it is done server side. Some things you can find more easily in chrome and some things you can find more easily in firebug, nothing wrong with using both tools.
I may not provide the completed solution you might desire, but I do try to provide honest suggestions to help you solve your issue.
Thanks for chiming in @peregrine. Much appreciated information.