anchor.diff:  = Asciidoctor PDF Theming
   :navtitle: Theming
   
  -Asciidoctor PDF comes with a built-in theming system and a default theme.
  -The theming system is used to control the layout and styling of a PDF file generated from AsciiDoc by Asciidoctor PDF.
  -You can use the default theme for your PDFs as it is, extend the default theme to change or add styles, or create and apply a custom theme.
  +Asciidoctor PDF includes a theming system that allows you to control the layout and styling of the PDF that Asciidoctor PDF generates from AsciiDoc.
  +The theming system comes with a default theme as well as several additional built-in themes.
  +
  +If you're looking for a professional-looking result, the default theme may suit your needs.
  +Other built-in themes offer variations on this style for different needs, such as print-optimized styling, extended character support (including emoji), or a sans serif font.
  +
  +If you want to customize the layout and styling of the PDF, you can extend one of the built-in themes to change or add styles or you can develop a custom theme from scratch.
   
   == Theme configuration and language
   
  
positive.code: The Asciidoctor PDF theme language is described using https://en.wikipedia.org/wiki/YAML[YAML] and incorporates many _concepts_ from CSS and SASS, such as selectors, properties, and inheritance.
  Therefore, if you have a background in web design, the terminology should be immediately familiar to you.
  *Note, however, that the theming system isn't actually CSS.*
  
  == Theme capabilities
  
  
negative.code: 
  //This document describes how the theming system works, how to define a custom theme in YAML, and how to activate the theme when running Asciidoctor PDF.
  //To learn how the theming system works and how to create and apply custom themes, refer to the <<docs/theming-guide.adoc#,Asciidoctor PDF Theming Guide>>.
  
  == Syntax highlighter style
  
  If you've enabled a source highlighter, you can control the style (aka theme) it applies to source blocks using the `coderay-style`, `pygments-style`, and `rouge-style` attributes, respectively.
  For example, to configure Rouge to use the built-in monokai theme, run Asciidoctor PDF as follows:
  