Just as a note: the "non-full-width" was indeed always the standard for pretty much all browser (at least as far as I use(d) them since ~1999). Netscape, IE, Safari, Opera, etc. This newer full-width design was only introduced two years or so ago.
Bug 1511219 Comment 7 Edit History
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Just as a note: the "non-full-width" was indeed always the standard for pretty much all browser (at least as far as I use(d) them since ~1999). Netscape, IE, Safari, Opera, Chrome, Edge, etc. This newer full-width design in Firefox was only introduced two years or so ago.