anchor.diff:  [#keys-footnotes]
   === Footnotes
   
  -The keys in this catagory control the style of the footnotes list at the end of the chapter (book) or document (otherwise).
  +The keys in this category control the style of the footnotes list at the end of the chapter (book) or document (otherwise).
   If the `footnotes-title` attribute is specified, it is styled as a block caption.
   The styling of the links is controlled by the global link styles.
   
  
positive.code: [CAUTION#transform-unicode-letters]
  ====
  Ruby 2.5 and better has built-in support for transforming the case of any letter defined by Unicode.
  You no longer need the `activesupport` or `unicode` gem to transform characters beyon the Basic Latin character set (e.g., accented characters).
  ====
  
  === Colors
  
negative.code:     center:
        content: $header-recto-center-content
  ----
  <1> You can use the `image-vertical-align` key to slightly nudge the image up or down.
  
  CAUTION: By default, the image must fit in the allotted space for the running header or footer.
  Otherwise, you will run into layout issues.
  