What do you mean by this? You still use CSS rules and selectors to style React components.
Also, maybe your coworker should up their interview game. Instead of asking “define this term” questions, maybe they should ask candidates to actually demonstrate skill.
(Also, it’s a bit weird to tell a “story” like this that happened to your coworker. Were you guys making fun of the candidate afterwards or something? I think we learned more about you and your coworker than about the candidate from your anecdote.)