A long menu or list cut its rows off flat where it ended, so the notebook
menu opened on half of Notebook Recycle Bin with its highlight sliced
through. Rows now fade out over 12 points towards an end where more lie
beyond it, as the section tabs fade at the ends of their row, and arrowing
through the list stops the highlighted row clear of the fade.

Assisted-by: claude-opus-5.5