It was capped at the device's own height, on the reasoning that a 390x844 phone drawn 1200 pixels tall
is not a phone. That was wrong, and the empty band under the preview in View was the tell.
Media queries answer WIDTH. The layout at 390 is the phone's layout whatever the height, so a taller
frame shows more of the page rather than a different device — a scroll position, not a viewport class.
Width stays the device; height is now simply the room there is.
DEVICES carries widths only. The heights had exactly one consumer, and it was the cap.
One consequence, and it is the right one: the footer is min-h-dvh, so it sits at the bottom of the
FRAME. A taller frame puts it lower, exactly as a taller browser window does.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>