Normally I’d just set a max-width there, but as Andy says:
This becomes a slight issue in mid-sized viewports, such as tablets in portrait mode, in long-form content, such as this article because contextually, the line-lengths feel very long.
So, on super large screens, you’ll get capped at 70rem (or whatever you think a good maximum is), and on small screens you’ll get full width, which is fine. But it’s those in-betweens that aren’t so great. I made a little demo to get a feel for it. This video makes it clear I think:
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