{{ $style := resources.Get "sass/main.scss" | resources.ExecuteAsTemplate "sass/main.scss" . | resources.ToCSS (dict "targetPath" "css/main.css") | resources.PostCSS (dict "config" "postcss.config.js") }}
<link rel="stylesheet" href="{{ $style.Permalink }}">

{{/* Page-specific styles set via front matter, scoped via SCSS and inlined */}}
{{ with .Params.css }}
  {{/* NOTE: This file doesn't end up getting published (which is good) */}}
  {{- $target := path.Join $.File.Dir "css/inline.scss" }}
  {{- $css := . | resources.FromString $target | resources.ToCSS | resources.PostCSS (dict "config" "postcss.config.js") -}}

{{/* Already being minified to my taste by PostCSS above */}}
{{ printf "<!-- htmlmin:ignore -->" | safeHTML -}}
<style>
{{ $css.Content | safeCSS }}
</style>
{{- printf "<!-- htmlmin:ignore -->" | safeHTML }}
{{ end }}