High zoom causes horizontal scrolling and overlapping control

[kenlhlui]

At high zoom, the recording shows page-wide horizontal scrolling and the Back to top button overlapping the sort area.	1.4.10 Reflow (WCAG 2.1); also test at 200% against 1.4.4 Resize Text	Let the header and results controls wrap at narrow widths, and move Back to top so it does not cover a control.