From 621 to ~800 px the header controls ran past the page (183 px at 621, 44 px at 760) and the page scrolled sideways. The "updated" line sized the controls as if it sat beside the picker. It now takes no width of its own, and the controls wrap under the title, flush right, when there's no room beside it (621–720 px).
Checked at 621–1280 px: no sideways overflow. 1280 and 420 look the same as before. Header text is unchanged. Smoke: all periods × breakdowns at 680 px stay on the page; theme toggle and pickers work; no console errors.
Before → after, 760 dark, light; 1280 dark, light; 420 dark, light:
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