Removing a second "powered by" line

I have removed the WordPress “powered by” text but my university has decided to similarly include an additional “powered by” line that I can’t seem to delete/not display this line. I’m using Twenty Twelve and the site is live: https://sites.duke.edu/brettjgall/

I turned off the WordPress line via including the following in my CustomCSS:

.site-info { display : none; }

However, all of the other hacks I have seen can’t seem to turn this line off.

Please note that I need a solution I can add to CustomCSS.