Move (lower) the floating menu in a theme

Hi all,

Hopefully this is allowed here...

I have added a sticky header plugin to one of my sites. Unfortunately it overlaps the menu. I don't suppose someone could take a look and see if there's a few lines of CSS that I can add to the theme to drop the menu (top left) by 10 or 20 pixels?

The site is here: http://gig.st/