I can see the issue you have here.
Your outer wrapper requires unique class applied to it (at the moment the same class name 'wrapper' is duplicated throughout. Then this can be set to a percentage width, and centered in the page (margin:0 auto;). You don't actually then require any other wrapper elements for your header, footer and main content section.
You can see from my own website [login to view URL] that I have a strong grasp of responsive design, and css.
Regards,
- Rob.