Mobile horizontal wiggle: overflow-x hidden on body alone fails on iOS

A page that scrolls sideways a little on phones but not desktop is usually layout overflow from absolutely-positioned centered elements (left:50% + translateX(-50%)) - transforms do not undo layout overflow, so they inflate scrollWidth past the viewport. body{overflow-x:hidden} alone does not stop horizontal panning in iOS Safari; put overflow-x:clip on BOTH html and body. Use clip, not hidden: clip avoids creating a scroll container, so position:sticky sections keep working. To reproduce mobile without devtools emulation, load the page in a 390px iframe - media queries respond to iframe width, and you can diff scrollWidth vs innerWidth inside it. Also swap 100vh for 100dvh (with vh fallback) on pinned sections to kill address-bar resize jank.