Comment by omnimus

Sounds more like you have some deeper hate towards tailwind. I am no tailwind fanboy. I write direct no framework css all the time and have been doing frontend for more than a dacade.

What i mean is that classes are used to save interactive state and if you have some component like dropdown or hamburger menu then adding class "open" is very common solution and for certain transitions you need multiple classes because of in-out durations. So what you do? Use custom attributes? Sure but then thats just semantic difference to using a class attribute.

Looking at docs of your project you are doing both

  posts.forEach(post => post.classList.add('fade-in'))
  AND
  main.style.display = 'block'

So whats with those claims?!