rimarima/themes/hugo-liftoff/layouts/_default/_markup/render-codeblock.html

{{ $lang  := .Attributes.lang  | default .Type }}
{{ if transform.CanHighlight $lang }}
  <span class="code-language">{{ $lang }}</span>{{ highlight .Inner $lang }}
{{ else }}
  <pre><code>{{ .Inner }}</code></pre>
{{ end }}