Hey, even if you don't win the first place spot, there is a badge for joining up and refining your gamepage.
CSS isn't necessary - look at the different aspects of your gamepage and clean it up a bit, give it a spit-shine.
Maybe it could use some graphical components?
Maybe it could use a bit of a polish on the description?
How about a banner instead of that old default name tag?
Some colours splashed in the text?
Hell, even if you add a background image (which is super simple - there's a code for it in the comments of the CSS tutorial!) or changing the game page colours, it counts.
(I mean, geez, I got help with fixing up this event page a bit, too. I know squat about CSS and I managed to put this together to look pretty effective.)