Chrome re-scrolls the focused editable into view on every keystroke and
honours the viewport's scroll-padding-top while ignoring the editable's
own scroll-margin (crbug.com/41492445) — so the sticky-header search
field, which sits above the 76px line and can never be scrolled below
it, dragged the page toward 0 one keystroke at a time, and the previous
negative-scroll-margin counter could not work. CDP harness bisection:
of all suspects (smooth scroll, sticky header, overflow clip,
animations, ambient layer, suggest siblings) only removing the global
scroll-padding stops the jump. TOC/skip anchor offset now lives as
scroll-margin-top on the in-content targets; harness confirms scrollY
constant while typing and anchors still land below the header.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012jWfn3RwPfFGTtBddm36Uy