CSS edit to contain event content?

Need help with some containment CSS. Using the Setting page to ask the plugin to respect the Theme's full page width doesn't work, so i need to edit CSS.

Can someone in Support show me what edit I need to make to get this:

http://purplepoppyinc.com/events/2012/11/holiday-open-house-3/

to remain centered and both columns within 960px?

Thank you.