You can quickly create a .primary-button (or whatever) class where you group all the Tailwind classes with an @apply. Then just add primary-button wherever you want.

https://tailwindcss.com/docs/reusing-styles#extracting-class...

I'd also add that the code in the Tailwind example is much easier to maintain and jump in on. It describes everything going on without you having to cross-reference a separate CSS doc with all of the actual meaning hidden in it. Joining a new project with 1000+ line CSS files + media queries randomly added throughout is a horrendous experience.