{{- $css := "" -}}
{{- range .Site.Params.assets.css -}}
  {{- $customCSS := resources.Get . -}}
  {{- if $customCSS -}}
    {{- if eq $css "" -}}
      {{- $css = $customCSS -}}
    {{- else -}}
      {{- $css = slice $css $customCSS | resources.Concat (printf "%s.tmp_custom.css" .) -}}
    {{- end -}}
  {{- end -}}
{{- end -}}
{{- return $css -}}