Compiled CSS is too large

[AndrewVos]

Describe the problem:

Using a fresh rails 6 app, install this gem and follow all the instructions. Use a few utilities in some html. Deploy to production on Heroku. If you look at the size of the resulting CSS, it's over 60kb.

This is unexpected because, from the tailwindcss docs:

Link to a minimal reproduction:

The code:
https://github.com/AndrewVos/testing-tailwind

The live app on Heroku:
https://testing-tailwind.herokuapp.com/

[AndrewVos]

Ok here's a commit that actually works: AndrewVos/testing-tailwind@993f348