You can save a page snapshot and you can also restore from one as well.
To restore a page snapshot you took, visit your page in your dashboard, go to the "Appearance" tab and scroll all the way down to "Page Snapshots". There you will see all your page snapshots you took.
Click the 3 dots on the left and click "Restore". A modal window will now open giving you some options.
Your Options are Full Restore and Styles only.
Full Restore restores your page to exactly how the snapshot was as you saved it. All your content, designs will be restored and other links that were not there WILL BE DELETED.
Styles only only restores your your page styles. All your content will be preserved and not added or deleted.
Select an option that fits your needs and thats it you are done!