{{/* Pragmatic deep merge for block sections: shallow merge + merge 'content' and 'design' submaps if present. b overrides a. */}}
{{- $a := .a -}}
{{- $b := .b -}}
{{- if and (reflect.IsMap $a) (reflect.IsMap $b) -}}
  {{- $result := merge $a $b -}}
  {{- /* merge 'content' submap */ -}}
  {{- $ac := index $a "content" -}}
  {{- $bc := index $b "content" -}}
  {{- if and (reflect.IsMap $ac) (reflect.IsMap $bc) -}}
    {{- $result = merge $result (dict "content" (merge $ac $bc)) -}}
  {{- end -}}
  {{- /* merge 'design' submap */ -}}
  {{- $ad := index $a "design" -}}
  {{- $bd := index $b "design" -}}
  {{- if and (reflect.IsMap $ad) (reflect.IsMap $bd) -}}
    {{- $result = merge $result (dict "design" (merge $ad $bd)) -}}
  {{- end -}}
  {{- return $result -}}
{{- else -}}
  {{- return $b -}}
{{- end -}}