- tap zones: map in-iframe taps into the visible page slice (the
iframe is laid out at full section width; every tap previously
computed as the left margin) and shrink the default zone size to 12%
- hyphens: manual on coarse pointers: Chrome's touch word-selection
walks hyphen fragments, re-anchoring line-start drags and
overshooting line ends into the next column
- selection popover: opens for settled touch selections (the gesture
takeover swallows pointerup), positioned below the selection with
on-screen clamping; creating a highlight clears the selection so
the browser's own menu follows
- settle-time recovery: return the view to the selection's anchor
page and clamp the selection to the visible page after the
browser's selection auto-scroll wanders off the page grid
- overscroll-behavior: none on the reader page (pull-to-refresh
during downward drags)