Why won't my code work?

Question

Bolded text and xx-small text aren't working
https://code.sololearn.com/WAuwIJU7Wh5Z/?ref=app

Answer 1

https://code.sololearn.com/W12yeL9EqIG6/?ref=app

Answer 2

You had created wrong class name and in css wrong property name.

Answer 3

https://code.sololearn.com/W6qVCr2EG2Os/?ref=app