anchor.diff:  NOTE: The background color spans the width of the page.
   When a background color is specified, the border also spans the width of the page.
   
  +==== Implicit attributes
  +
   In addition to the document-level attributes defined in the AsciiDoc document, the following attributes are available when defining the content keys in the footer:
   
   * page-count
  
positive.code:   verso_content:
      left: '{page-number} | {chapter-title}'
  ----
  
  == Applying your theme
  
  
negative.code: * section-title
  * section-or-chapter-title
  
  Here's an example that shows how these attributes can be used in the running footer:
  
  [source,yaml]
  ----
  