These are the CSS text template files used by these XSLT stylesheets.
They are maintained in separate files to make it easier to work on them.
You can call variables or XPath expression with double curly braces {{$like_this}}.
Variables are defined in the XSLT files.

Because of limitations in XSLT, these files do have to be well-formed XML,
even though we only ever use the text value.
That means they have to be wrapped in an XML element,
and any < and & characters have to be escaped as &lt; and &amp;, respectively.

Here's what each file is:

* core.css.tmpl     - The core CSS for general page layout
* elements.css.tmpl - CSS for element styles common to multiple formats
* syntax.css.tmpl   - CSS for syntax highlighting, using highlight.js
* mallard.css.tmpl  - CSS for element styles specific to Mallard
* docbook.css.tmpl  - CSS for element styles specific to DocBook

The easiest way to test your changes to these files is with the mallard test document,
found under test/mallard from the root of this repository.
That directory has a README that explains how to use it to test changes.
