Thank you for the replies

The design will probably be improved upon once we go public or after a month or two. Our focus now is on getting the functionality done. Then testing. And if the site is popular enough, I'll let a professional designer do his work. 

Some technical details for whose interested. The site template is based on twitter bootstrap which provides a very good and clean start. The backend code uses the php laravel framework for most of the pages. The quiz game itself however works with node.js and sockets.io because it's very fast and fancy. Data for active quizzes is stored in Redis.