> For example if you want to customize a Bootstrap button, you need to write additional CSS files No you don't need to write CSS files for that. Bootstrap also

> For example if you want to customize a Bootstrap button, you need to write additional CSS files No you don't need to write CSS files for that. Bootstrap also offers utility classes. If I want to customize padding I can add "p-3" or "p-4" class for example. Same for other properties including colors like "bd-blue-800". See: https://getbootstrap.com/docs/5.0/customize/color/ https://getbootstrap.com/docs/5.0/customize/color/