By the way, the logo might get changed to a new one soon.
just use the 100% width size for the banner, it'll stretch then.
also a useful website for checking this sort of stuff: http://viewlike.us/
But I'm going to make a new banner anyway.
and it stretches on large screens. yours doesn't. so yours can't be set on 100 %. ;P the size of the banner is important, but the way you add it - more important. ^^