[SOLVED] Increase size of centre area

Hello, I find that the left edge of the central area of my blog is too close to the text (see attached picture). I would like to increase the left margin further so that there is more white space on the left. How do I go about doing that? I've been poking around the Atahualpa Theme Options menu but can't see how to do it.



The blog is here if you would like to take a look. There's really nothing there yet, I've been working on it off and on for a few weeks now.

ETA: Forgot to mention, I'm using Atahualpa 3.5.3