Trying this out and it seems to be a very nice plugin. However, I'm frustrated by the styling of the code. There is a lack of space between the rule and the code, and a lack of space between lines, that is very hard on the eyes. When I try to affect these through the css, I seem to be able to affect the code but not the line numbers. Can you direct me to a way, within the css or your plugin's settings, to give us a bit of padding within the box, at least? It's just bad visually to have it all so crunched together. You have given us margin settings for space above and below the box, but not within, as far as I can see.