Random gap at top of page.

So I’m not exactly sure how this happened. I’ve been editing the theme I’m using to suit my tastes. And recently I’ve noticed that at the top of my pages, there is a large gap. The top of the menu should be the start of the page.

I’m sure there’s a simple explanation for this (something like: remove the page return from a .php file).

Any advice how to track this down? It’s really bugging me 🙁

banedesigns.gamingisstupid.com is my site.