Basic customization in publish settings directly for published site with preview

Use case or problem

Would really appreciate being able to do some basic customization for the published site in publish settings without having to change publish.css ourselves

What comes to mind for now:

  1. Font sizes for different parts of the site
  2. Font options for different parts of the site
  3. Default image width
  4. Line height for different screen sizes

And have preview for screens like phone and web in settings

Proposed solution

Users can directly change them in publish settings without needing to change publish.css themselves with previews