PostCSS - "Error: cannot find module 'tailwindcss'"

Thanks for the suggestion, but I definitely ran npm install right after hugo mod npm pack and I have a populated foo/node_modules directory that includes tailwindcss.

Here’s my hugo env

hugo v0.88.1-5BC54738+extended windows/amd64 BuildDate=2021-09-04T09:39:19Z VendorInfo=gohugoio
GOOS="windows"
GOARCH="amd64"
GOVERSION="go1.16.7"