The ruler is different for all my documents in a same file

I’m writing a book and I have a problem. I realized it because when I compiled everything to check how it looked like on Word, I saw that the chapters didn’t have the same margins on the right. (on Scrivener I write one chapter on one file, child of a folder which represents the different parts of the book)
How is it possible to standardize the margin (or the ruler ?) on the right for the whole set of chapters ?
Because when I use Tools, then Edit they say it’s for the new documents …

Thank you for your answers