How to edit your content in Preview mode
Login to the CMS.
Go to any page in the node tree, e.g. click on Home.
In the bottom right, click on 'Save and Preview'.
'Preview' mode will now load in a new window or tab.
Once in 'Preview' mode on the right-hand side, you will see two buttons. One with a Paint Bucket icon and the other a Pencil icon. Click on the 'Pencil' icon to access the Live Editor.
In the slide-out panel, click on 'Edit text'.
You can now start editing any text on your page to preview how it will look across a range of screen sizes.
Please note, any text changes you make will NOT be saved. This is for testing only.