Yes that is the style for when the language is setup for left to right text.
If you are basing your new theme on the Denim theme ideally you will want to create a child theme. This way in most cases you just include the changed files in the new theme and Geeklog will fallback to the Denim theme for any files it does not find. The Modern_Curve theme is based on the Denim theme and is a good one to see as an example. Some files like functions.php and the images are required in the new theme folder.
As for the changes. You would have to look for any of these lines and then update the css as you see fit.
PHP Formatted Code@
media only screen and (
In the css file there is also a comment (search for "Layout Pattern"
which helps explain the pixels used.
Also search for in the file "Center Block Container" and look at the css classes below it. (it appears several times)
This is not just a one line change and I don't know enough to really help with it. dengen
created the theme and would be the best one to contact about it.
One of the Geeklog Core Developers.