mehl.mx/themes/hugo-sustain/layouts/partials/head/css.html

<!-- Static, third-party CSS -->
{{- range (slice "css/bootstrap-3.3.7.min.css" "css/fontawesome-all.min.css") }}
  {{- with resources.Get . }}
    {{- 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 }}

<!-- Theme stylesheet, combination of all in assets/scss -->
{{- $style := resources.Get "scss/main.scss" | resources.ExecuteAsTemplate "scss/main.scss" . | toCSS (dict "targetPath" "css/main.css" "enableSourceMap" false) }}
<link rel="stylesheet" href="{{ ($style).RelPermalink }}?v={{ md5 $style.Content }}">

<!-- Custom CSS -->
{{- range .Site.Params.custom_css }}
{{- $md5 := md5 (readFile (printf "static/%s" .)) }}
<link rel="stylesheet" href="{{ relURL . }}?v={{ $md5 }}" />
{{- end }}