Remove Border/Padding in Pages

Hi

My website is http://www.celbo.co.za and I am using the Seguente theme.

I am struggling to remove borders/padding on my pages. My home page is fine but on all my other pages, there seems to be grey borders or padding. So directly under my heading there are 2 grey lines (see http://celbo.co.za/retirement-planning/).

How do I go about removing this off all my pages?