anchor.diff:  ----
   
   You can use the key that you assign to the font in the font catalog anywhere the `font-family` property is accepted in the theme file.
  -For instance, to use the Roboto font for all headings, you'd use:
  +For example, to use the Roboto font for all headings, use:
   
   [source,yaml]
   ----
  
positive.code: * bold_italic
  
  You'll need all four styles to support AsciiDoc content properly.
  _Asciidoctor PDF cannot italicize a font dynamically like a browser can, so you need the italic style._
  
  Once you've obtained the TTF files, put them into a directory in your project where you want to store the fonts.
  It's recommended that you name them consistently so it's easier to type the names in the theme file.
  
  Let's assume the name of the font is https://github.com/google/roboto/tree/master/out/RobotoTTF[Roboto].
  Name the files as follows:
  
  * roboto-normal.ttf (_originally Roboto-Regular.ttf_)
  * roboto-italic.ttf (_originally Roboto-Italic.ttf_)
  
negative.code:   font-family: Roboto
  ----
  
  When you execute Asciidoctor PDF, specify the directory where the fonts reside using the `pdf-fontsdir` attribute:
  
   $ asciidoctor-pdf -a pdf-theme=basic-theme.yml -a pdf-fontsdir=path/to/fonts document.adoc
  
  WARNING: Currently, all fonts referenced by the theme need to be present in the directory specified by the `pdf-fontsdir` attribute.
  
  TIP: When Asciidoctor PDF creates the PDF, it only embeds the glyphs from the font that are needed to render the characters present in the document.
  Effectively, it subsets the font.
  While that saves space taken up by the generated PDF, you may still be storing the full font in your source repository.
  To minimize the size of the source font, you can use FontForge to subset the font ahead of time.
  Subsetting a font means remove glyphs you don't plan to use.
  Doing so it not a requirement, simply a personal preference.
  
  You can add any number of fonts to the catalog.
  Each font must be assigned a unique key, as shown here:
  