Where is the CSS within this project?

[Aiyush-G]

On opening the example you can see the "Welcome to GrapeJS" box, the "welcome" to text has a welcome class. I can see that this is inherited from index.html put when I add a block it has a class e.g paragraph. Assigned to it, where does this come from?

I would like to include CSS within the canvas, however, when try this:

styles: [ 'https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css' ]

the canvas renders blank.

Kind Regards Aiyush