Support Threads

Hello, I don’t know why whether my own mistake or from wherever… my menu is not flush when I scroll down. On the right side and at the top and the bottom of the menu it stands above. The orange line on the right side is the border. The width of the menu is 1080px.…

I would like to know how I can edit the width of the boxed site layout. I want to increase it by myself. The problem is for me that I have no overview over the html codes for editing this. Can you help me please? I want to change the boxed-width. Thanks a lot :)