Something is broken in your site’s code some where…it was the first thing that I noticed when I went to your site. The really hard part is to find out what and can be quite time consuming. I would first recommend disabling mailchimp and seeing what happens, then disable other plugins one at a time. It could even be your own content that is missing as simple as a closing tag or even a missing quote on a piece of code or style….could be one of many things.
Did you make any core theme file layout changes? I could tell the layout is broken because the containers are doubled up and showing outer glow when it should just be the one container.