anchor.diff:  
   [,yaml]
   ----
  +extends: default
   footer:
     height: 0.75in
     line-height: 1.2
  
positive.code: 
  [,yaml]
  ----
  header:
    height: 0.75in
    line-height: 1
  
negative.code: 
  By default, the running content starts on the first page of the document body.
  You can specify on what page the running content starts using the `start-at` key.
  The `start-at` key is set on the top-level `running-content` key in your theme.
  
  [,yaml]
  ----
  