demo · v135
Inertness tree walker
A live DOM walker shows which buttons in a nested layer tree are currently inert. Toggle interactivity: inert on any branch and the walker re-marks every descendant in red — mirroring exactly what the focus ring and click handlers experience. The walker uses checkVisibility({ checkInert: true }) from the same milestone family to compute its verdict.
interactivity: ?
walker output
Try Tab/Shift+Tab to walk focus through the tree — the inert branches will be skipped.