Using CSS when converting Markdown to PDF with Pandoc

"I'd like to apply the class "filename" to the enclosed text in each case, but it doesn't seem to do anything to the output."

It works for HTML. Running Pandoc interactively, ^D to see the resulting code:

$>  pandoc -f markdown -t html

* Create a simple HTML document (`simple.html`{.filename}) and load it.

^D

<ul>
<li>Create a simple HTML document (<code class="filename">simple.html</code>) and load it.</li>
</ul>

It doesn't work for LaTeX if you use the .filename class. You need to use one of the known classnames:

$>  pandoc -f markdown -t latex

* Create a simple HTML document (`simple.html`{.filename}) and load it.

^D

\begin{itemize}
\tightlist
\item
  Create a simple HTML document (\texttt{simple.html}) and load it.
\end{itemize}

Now using one of the known classnames, like .bash, .postscript, .php, ...:

$>  pandoc -f markdown -t latex

* Create a simple HTML document (`simple.html`{.bash}) and load it.

^D

\begin{itemize}
\tightlist
\item
  Create a simple HTML document (\VERB|\KeywordTok{simple.html}| and
  load it.
\end{itemize}

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To convert HTML + CSS into PDF, you can also look into PrinceXML, which is free for non-commercial use.