How to add class to extend block in jade?

Question

HTML

Hello! I have 2 pages - parent.jade:

div.about
  block about

And child.jade:

extends parent
block about

How can I add a class to the about block in child.jade?
The output html file should look like this:
<div class="about about--red"></div>

Answer 1

it won't work that way.
It is necessary to place div.about in parent.jade in block about, then in child.jade you can write:

block about
  div.about.about--red

Answer 2

I didn’t quite understand, what does jade and classes have to do with it?

.about.about--red
# <div class="about about--red"></div>