FYI, I've discovered a small issue with the Leatherbound theme. The footer also has the .wrapper class assigned. This causes the block to be larger than the page width (due to a right/left margin) so there is a right/left scroll bar. Simple solution is to add another <div> and move the .wrapper class there. This applies to both the frontpage.php and general.php layouts.

https://github.com/moodle/moodle/blob/v2.5.0/theme/leatherbound/layout/general.php#L120