[Theme: Atahualpa] How can I remove the header border?

Okay, I’m trying to remove the 5px solid top and bottom border from my header image. I was able to locate the code for them using Firebug, but I can’t find it in the CSS anywhere OR in the Atahualpa theme options (believe me, I’ve looked).

Here’s a screenshot of the header w/borders.
Here’s a shot of the header w/o borders (removed with firebug).

Here’s a shot of what I see in firebug, but can’t find in the CSS.

Can anyone point me in the right direction? Keep in mind that I’m a total n00b at CSS and html (to an extent). I know just enough to get by.

Thanks!!

http://wordpress.org/extend/themes/atahualpa/