Of course, a well-crafted prompt and RAG or other means of retrieving relevant information can work very well.

The reason why I was asking is that as a potential customer, I kinda feel cheated reading about a langcss.fast model that doesn't actually exist. I don't think there's any need for putting this misleading (well, actually not even misleading; just plain wrong) information on the website, to make potential customers think you've trained a custom model on tailwind etc.

Honesty is a very attractive selling point, at least to me, and I'd bet it is to others too.