How to configure Hugo to use the TailwindCSS v4 binary instead of npm?

Hi everybody, I’m new here.

I’m building my first fully fledge website. I’m building the theme and the website to consume the theme. I want to use TailwindCSS v4, but I don’t want to use the npm CLI version. I have installed the TailwindCSS binary and it is already in my PATH, but Hugo is looking for the npm one, not the binary CLI.

Error: error building site: TAILWINDCSS: failed to transform "/css/main.css" (text/css): npm notice 

I don’t want to use npm. To give more context, the only thing I did was editing the partial that comes with the default hugo new theme command:

{{- with resources.Get "css/main.css" }}
  {{- $opts := dict "binary" "tailwindcss" "minify" true }}
  {{ with . | css.TailwindCSS $opts }}
    {{- if eq hugo.Environment "development" }}
      <link rel="stylesheet" href="{{ .RelPermalink }}">
    {{- else }}
      {{- with . | minify | fingerprint }}
        <link rel="stylesheet" href="{{ .RelPermalink }}" integrity="{{ .Data.Integrity }}" crossorigin="anonymous">
      {{- end }}
    {{- end }}
  {{- end }}
{{- end }}

And added this to the hugo.yaml file:

build:
  cachebusters:
    - source: "assets/css/.*.css"
      target: "css"

The tailwind binary is accessible from my command line with the tailwindcss command.