Module overlay 

Structs

OverlayOffset

Overlay offset from the trigger.

OverlayPosition

Calculated overlay position.

OverlayRect

Rectangle in viewport coordinates.

Enums

OverlayPlacement

Overlay placement relative to a trigger element.

Functions

calculate_overlay_position

Calculate a viewport-aware overlay position.

install_overlay_anchor_watch

Install the global scroll/resize watcher. Idempotent — safe to call per overlay.

next_overlay_anchor_revision

Await the next scroll/resize revision. None means the bridge is gone (the document went away), which ends the caller’s loop rather than spinning.