At 1800px the article ended 391 pixels short of the contents rail. That was not breathing room, it was a hole: the column took 1fr while the article capped at the measure, so the leftover sat between them.

The column now sizes to its content and the block centres. Running text still caps at the measure — 73 characters a line, where reading wants 45-75 — but a code block, a table or a diagram gets the whole column, because wrapping those to prose width is what makes people scroll sideways. Measured on fossil's th1.md: prose 625px, code up to 1216. closed check-in: d11bec1130 user: dmestas tags: doc-measure