title: Using CSS in Markdown file removes other styling
body: <p>I want to add custom CSS in my Markdown (.md) file. I have looked here : <a href="http://www.mkdocs.org/" rel="nofollow noreferrer">http://www.mkdocs.org/</a> and found the extra_css, but I wish to have the CSS in the same file.</p>
  
  <p>I have tried adding style tags at the top of the page like so :</p>
  
  <pre><code>&lt;style&gt; body { background:red } &lt;/style&gt;
  </code></pre>
  
  <p>But it seems to remove all the other styling on the page.</p>
  
  <p>Question is, how do I add my own CSS to my markdown file ?</p>