{{ $styles := resources.Get "css/index.css" }}
{{ $styles = $styles | postCSS }}
{{ if hugo.IsProduction }}
  {{ $styles = $styles | minify | fingerprint | resources.PostProcess }}
{{ else }}
  {{ $styles = $styles | resources.ExecuteAsTemplate (printf "css/index.dev.%v.css" now.UnixNano) .}}
{{ end }}
<link href="{{ $styles.RelPermalink }}" rel="stylesheet" />