tailwind element missing in production (Heroku)

Hello,
I have a button element styled with default Tailwind classes which works fine in my local machine. However, the entire button is gone in production (Heroku), even though I can see the erb line via CLI.

Anybody faced the same issue?

The erb line in index.html.erb:

  <%= link_to "explore", new_user_session_path, class: "btn btn-primary text-lg uppercase lg:mr-4 mr-0 lg:mb-0 mb-4 bg-gradient-to-r from-violet-600 to-pink-600 hover:drop-shadow-xl" %>


What puzzles me is that other styles, including a custom background image added in tailwind.config.js shows up normally in production.