anchor.diff:  * bold
   * bold_italic
   
  -You'll need all four variants to support AsciiDoc content properly.
  -Otherwise, the converter will either crash or revert to the fallback font, depending on how your theme is configured.
  -If one of the variants is missing from your collection, you can simply reuse the normal variant in its place.
  -
  -WARNING: Asciidoctor PDF cannot italicize a font dynamically like a browser can, so the italic styles are required.
  +You'll need all four variants to support AsciiDoc content properly (unless the font only has a single variant).
  +If you do not register the font correctly, the converter may crash or revert to the fallback font, depending on how the theme is configured.
  +If one of the variants is missing from your collection, you can simply reuse the normal / single variant in its place.
  +
  +WARNING: Asciidoctor PDF cannot italicize a font dynamically like a browser can, so the italic styles are required to italicize text.
   
   Once you've obtained the TTF files, put them in the directory inside 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.
  
positive.code: ----
  font:
    catalog:
      Roboto:
        normal: roboto-normal.ttf
        italic: roboto-italic.ttf
  
negative.code: 
  ==== Declaring Your Font
  
  Next, declare the font under the `font-catalog` key at the top of your theme file.
  Assign each font a unique key (e.g., `Roboto`) and specify the path to each of the four font styles under that key.
  
  [source,yaml]
  ----
  font:
    catalog:
      merge: false # set value to true to merge catalog with theme you're extending
      Roboto:
        normal: roboto-normal.ttf
        italic: roboto-italic.ttf
  