What would you teach a frontend beginner in 2020?

In April, I will start teaching frontend development to design students at university.

The course curriculum wasn't updated for years, so I'm basically free to choose what to teach.

The idea is teaching them enough so they can implement a basic interactive prototype of their design idea with Web technology. They only have 4x13 hours to do this course and it isn't their main "project" in the semester.

I already have an idea what I will do, but I wanted to reach out to the community to see what your perspectives are.

What would you teach a frontend development beginner in 2020 if you would have to break it down to the bare essentials?