hugo-theme-relearn/assets/css/theme-auto.css

{{- $themevariants := partial "get-theme-variants.hugo" . -}}
{{- $themevariantsauto := slice | append (.Site.Params.themeVariantAuto | default slice) -}}
{{- $i := 0 -}}
{{- if eq (int (len $themevariantsauto)) 0 -}}
	{{- range $themevariants -}}
		{{- $i = add $i 1 -}}
		{{- if ne .identifier "auto" -}}
			{{- $themevariantsauto = $themevariantsauto | append .identifier -}}
			{{- break -}}
		{{- end -}}
	{{- end -}}
{{- end -}}
{{- if eq (int (len $themevariantsauto)) 0 -}}
	{{- $themevariantsauto = $themevariantsauto | append "relearn-light" -}}
{{- end -}}
{{- if eq (int (len $themevariantsauto)) 1 -}}
	{{- $poppedthemevariants := last (sub (len $themevariants) $i) $themevariants -}}
	{{- range $poppedthemevariants -}}
		{{- if ne .identifier "auto" -}}
			{{- $themevariantsauto = $themevariantsauto | append .identifier -}}
			{{- break -}}
		{{- end -}}
	{{- end -}}
{{- end -}}
{{- if eq (int (len $themevariantsauto)) 1 -}}
	{{- $themevariantsauto = $themevariantsauto | append "relearn-dark" -}}
{{- end -}}
{{- $themevariantsauto = ($themevariantsauto | first 2) -}}
{{- with index $themevariantsauto 0 -}}
@import "{{ printf "theme-%s.css" . }}" screen and (prefers-color-scheme: light);
{{ end -}}
{{- with index $themevariantsauto 1 -}}
@import "{{ printf "theme-%s.css" . }}" screen and (prefers-color-scheme: dark);
{{ end -}}