HN has a good layout - there are some (quite small) margins but it otherwise uses most of your screen. More websites should follow this pattern, IMO.
Requiring the user to resize the window is not a great alternative, IMO. It feels cumbersome, and people with many tabs will hate it. And doesn't work on mobile devices.
Will link or write another reply if I can succeed. I have no time to look at it right away.
If long line length was common then browsers would have a similar feature built-in.
I wouldn't be so sure. It was common for a long time (and still is on older sites) and browsers never got that feature. They also haven't bothered with a dark/light mode switch even though that is a much simpler feature since the setting is already there.
I prefer that be left to me to size the column for my reading preference, by setting browser size accordingly, though I appreciate a great many users browse full-screen at all times and designers need to account for that lest they be blamed for the users choices.
> Unfortunately there is no setting to communicate text width preference
Many sites have an explicit dark/light mode toggle, either instead of or as well as respecting prefers-color-scheme. Perhaps a “constrain width” toggle could similarly be implemented.
Yes, this is also horrible.