You can't retro fit responsiveness. Or at least you can, but it's such a bad idea that no one should try it. It's the quickest route to legacy CSS that no one w

You can't retro fit responsiveness. Or at least you can, but it's such a bad idea that no one should try it. It's the quickest route to legacy CSS that no one will every want to touch again. It means starting again, from design and UX all the way up to build. So for the entity that owns the website/web app it's going to be painful, but for every new website/web app, it's the norm and is pretty easy.