Two great things about Tailwind:

- AI already have data about its classes in their training data - No conflicting styles

This means that AI doesn't need to reference any existing stylesheets when generating new styles, which is great for context management.

With custom CSS, you'll have AI read existing stylesheets because otherwise its going to write conflicting styles or rewrite stuff you already have. This can be a problem if you have large stylesheets that take too much space in AI memory.