@floating-ui/core

Add 'layoutViewport' string option to rootBoundary. Unlike the visual 'viewport' boundary, it remains stable while pinch-zooming or when a mobile software keyboard is open, and unlike a manually passed Rect of the documentElement's client size, it accounts for space reserved by scrollbar-gutter: stable.

core: Reduce bundle size with behavior-identical middleware simplifications

inline: no-op on empty client rects and detect RTL disjoined line rects

Support explicit undefined for optional properties with exactOptionalPropertyTypes

size: Correctly compute available size for centered elements overflowing both sides

Bundle and runtime improvements

detectOverflow configurable via platform

flip: Ensure perpendicular axis flips with crossAxis alignment

Reduce memory allocations

flip: Only allow fallback to the perpendicular axis if all placements on the preferred side axis overflow the main axis with crossAxis: 'alignment'

flip: Add "alignment" string value for crossAxis option. This value determines if cross axis overflow checking is restricted to the alignment of the placement only. This prevents fallbackPlacements/fallbackAxisSideDirection from too eagerly changing to the perpendicular side (thereby preferring shift() if overflow is detected along the cross axis, even if shift() is placed after flip() in the middleware array).