It doesn't look bad, but as Alex P said the header is shifted to the right (I'm on 1920x1080) - looks like its not been tested on higher res monitors, but that should be an easy fix!
My only complaint with it is the chat box itself, there is a lot of whitespace around it and doesn't seem to stand out, something which I would expect considering it is the main feature of the website! Maybe make it a bit bigger and add some feedback to it, such as a hover effect or maybe a more prominent border?
Other than that I like the overall design!
Lee