title: I can't change jekyll syntax highlighter at my github blog
body: <p>I made my github blog.<br />
  I want to change my syntax highlighter to rouge.<br />
  I do this.</p>
  <pre class="lang-sh prettyprint-override"><code>gem install rouge
  rougify style monokai.sublime &gt; assets/css/syntax.css
  </code></pre>
  <pre><code>//default.html
  link href=&quot;{{ site.baseurl }}/assets/css/syntax.css&quot; rel=&quot;stylesheet&quot; /&gt;
  </code></pre>
  <pre><code>// _config.yml
  markdown: kramdown
  highlighter: rouge
  kramdown:
    input: GFM
    syntax_highlighter_opts:
      default_lang: html
      css_class   : 'syntax'
  </code></pre>
  <p>But my blog's syntax highlighter stay none.</p>
  <p>How can I change this?</p>
  <p><a href="https://github.com/azzyjk/azzyjk.github.io" rel="nofollow noreferrer">https://github.com/azzyjk/azzyjk.github.io</a>.<br />
  <a href="https://azzyjk.github.io/GithubBlog_2/" rel="nofollow noreferrer">https://azzyjk.github.io/GithubBlog_2/</a></p>
  <p><a href="https://i.stack.imgur.com/MxycM.png" rel="nofollow noreferrer">Chrome DevTools Picture</a></p>