Interaction experiments.
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Undo toast
Toasts stack up with a countdown ring; Undo pulls one back before it is gone.
Instead of a confirm dialog, the action just happens and a toast offers to take it back for a few seconds. The ring is the deadline, drawn as the visible length of a circle so it drains rather than blinks.
New toasts land in front; older ones step back, shrink a touch and dim, so a burst of actions reads as a stack rather than a list.