Sidebar is not responsive

Hello,

I have a problem with the sidebar in this site :
http://thierry-caillat.willartedition.net/

It doesn’t going at the end of the site as usually.

I think this is a problem with my child them but I tried deactivate all files and nothing good happen.

There is nothing about the sidebar in child theme css…

Please can you take a look because I do everything I think about…

Thanks