Did click the 3 dots and cutomize to see if you can move the url to top? Or are you talking about the menu toolbar? That screenshot looks like what the standard url/toobar/menu layout looks?

(1) Your toolbars are in the normal vertical order.

If you were previously using custom style rules in a userChrome.css file to rearrange the vertical order, it looks like the file either is not being applied or the rules are broken. When was the last time it worked?

Did your Firefox undergo a "Refresh"? The telltale sign is a new folder on your Windows desktop named Old Firefox Data. If you have that folder, hang onto it, since you can mine it for old files.

(2) Page layouts often are not full-width, because readability experts suggest avoiding overly long lines (they cause reading fatigue).

But if you think this is not the site's normal layout, hmm, I don't know why Firefox would add its own margins. ??

(3) The Bookmarks Toolbar can be set to show itself only when you are showing Firefox's new tab page. The following article describes how to switch that, but in short, you can try Ctrl+Shift+B once or twice.

Bookmarks Toolbar - Display your favorite websites at the top of the Firefox window