I haven't tried it personally but my understanding from friends is that Pangram is very accurate, at least for now.
That style is still rare enough that I prefer it over OP's "we installed shadcn + Tailwind and look like every seed-stage startup SaaS from 2024" style.
Or since a lot of vibe coded static sites are just plain html, cs, js, a first try attempt via wget to mirror the first 500KB of the site and then analyze it.