MyBB Community Forums

I'm currently editing the default theme on my forum to use the county colours. Sky blue and Navy Blue.

I have managed pretty ok so far and have the colours I want where I want them.
I want to set the width of the theme to 70%, no problem except for the top and bottom sections, indicated with red arrows, which obstinately remain full screen width. 

Any idea on how to set the width for these areas? Thanks.

You have to add your header class and footer class in the wrapper and set the width of wrapper to be 70%.
That would make it work.
Hope it helps