A word stranded on its own line

The eye reads a block's shape before it reads the words. A heading whose last line holds one word reads as a mistake to someone who could not name what is wrong with it — the silhouette says unfinished, and that impression lands before the sentence does. This is invisible in the source. The same heading breaks cleanly at 1280px and badly at 900px: where a line breaks depends on the box, the face and the string together, and none of the three is decidable from the others. It is judged on the rendered page at more than one width, which is why it carries pass: screen, and the render probe also lays the page out without text-wrap: pretty, as those browsers do, because a page can be clean in one browser and stranded in the reader's. A manual break is not the fix. <br> placed by eye is correct at exactly one viewport width and wrong at the next, and it survives into every layout the component is later used in. Ragged-right is not the failure — that is correct, and B-12 requires it. The failure is a *stranded* word, not an uneven edge. Do not chase every short last line; chase the one that is alone.