Grey borders problem

Hi

I love Your theme. It is very fast and responsive.
I have one problem…
In my site besmarketing.com.pl when You click on “O mnie” or “Oferta” everything is ok and page opens with text in grey borders. Entire page (text) is framed. But when You click on “B””E””S” or “T” there are grey borders on the top but there isn’t any on the bottom of the site (text). I think something is wrong. Maybe You have idea what to do.
Sorry for my English
Thank You for answer