Toast

The tone is a 3px left rule — the same one Callout uses. Status never floods a surface.

Viewport is bottom-centre on mobile (thumb reach plus the safe area) and top-right from md. Toast sits at z-index 500, above modal on purpose: "saved", "failed to save" and "connection lost" must reach the user while a dialog is open. Every error toast carries its recovery action — an error without one is incomplete.