hackathon web page displays strangely

http://act.qa-hackathon.org/qa2015/main

In Firefox, at least, all the pages on this site are displaying in a 
strange way.  Each page has a left sidebar with internal links and a 
right sidebar with sponsors.  But the main content for each page only 
starts to appear *below* the end of the longer of the two sidebars. 
Unless and until you scroll down past the sidebars, each page appears 
void of content.