Getting rid of a white space

I want to get rid of a white space above my menu bar: https://img.skitch.com/20110808-x9rfdjsfpq66s8bwik723u5a1x.jpg

I’m using theme Twenty Eleven.

I changed the default images; I created new images with the same file names — I kept the new images the same width, but they are less deep.

The white space that has appeared and that I want to get rid of didn’t actually appear when I changed the images.

Seems strange to me, but the white space appeared after I changed font sizes and styles — you can see I’m using Courier for some of the fonts now.

Here’s an image from before I changed the fonts — you can see there is no white space here: https://img.skitch.com/20110808-pj4aq43qtkyb81678bst5uj4is.jpg

And here’s a link to the site now: https://richardclunan.com/

Do I need to make changes to the CSS relating to the image size change?

How do I get rid of that white space?

Thanks, Richard