Menu not central

Hi, I have just installed Catch Box theme having tried some of your other themes and like them. The problem I have is the menu bar seems to be too far to the left, when I select the left button the highlighting goes over the edge of the menu bar if that makes sense. Have tried it in Chrome, Opera and Safari with the same results. My site, still under construction is at www.rvyc.org.uk/wp Thanks in advance!