Trying things out is part of it, and not every idea still pleases you on second glance. That is what the two arrows in the header are there for.
Undo and redo
The arrow pointing left takes back your last change (Cmd/Ctrl + Z).
The arrow pointing right restores it (Cmd/Ctrl + Shift + Z).
If the arrows are greyed out, there is nothing to take back or restore right now.
The editor remembers up to 50 steps. What it records are content changes, adding, deleting and duplicating sections, the order, hiding and showing as well as your settings under „Stil & Schriften" (style and fonts). What it does not record are pure matters of view: switching between Desktop and Mobile, selecting a section, the language preview and playing the envelope animation.
The envelope intro itself is not part of the history either. It is chosen under Dashboard → Webseite (your website) and saved immediately there, so you simply switch it back if you want to.
Good to know: The history only applies to your current session. If you reload the editor or come back the next day, it is empty. A deleted section cannot be brought back then.
The four keyboard shortcuts
Cmd/Ctrl + S: save
Cmd/Ctrl + Z: undo
Cmd/Ctrl + Shift + Z: redo
Escape: clear the selection and go back to the section list
There is deliberately no shortcut for deleting. Sections only disappear through the three dot menu or the bin icon, and always only after a confirmation.
Frequently asked questions
I undid something and then carried on working. Redo does not work anymore.
That is right. As soon as you change something new after an undo step, the way forward ends. The new state is then the valid one.
Can I take back a change from yesterday?
Sadly not. The history starts fresh every time you open the editor. Whatever you would like to take back is best taken back in the same session.