No Undo functionality

On a laptop screen everything is pretty tight so it’s a bit dicey to make sure I’m changing or deleting the right element with my cursor position. I accidentally deleted a full block when trying to delete a separator. I immediately tried to do a ctrl-z Undo but you don’t seem to support Undo. Luckily I restored the page just before the next auto-save would have made retrieval impossible. You should definitely support Undo.