I really need your help.
I faced problem when I add widgets such as ninja form or tab responsive into my page they falls over on footer.
Page suppose to expand body for content but it expand footer for that purpose. Unfortunately website is in Russian but I think you can see what’s going on.
In page source it shows that #content take height: 755px; when I try to modify it in style.css.
I does not make changes. When I set auto I works but not permanently.
Add to your #footer clear: both; in your CSS and it's fixed.
Your #primary has a float, that's why the content is over your footer.