I have a small problem I am doing a footer on my website and when I look at the preview there is a space all around my page not only for the footer. And my footer has like a margin on the bottom. Here is my page in the design manager :Design manager
And here is my CSS file: CSS File
And you can take a look at the preview :Preview
In the pictures you can see the small areas around the content.
Could you please help me I don't understand how it works.