title: Background highlight text in a code block?
body: <p>My goal is to be able to display something like this:</p>
  
  <p><img src="https://i.stack.imgur.com/uvnSv.png" alt=""></p>
  
  <p>I want to <strong>background highlight</strong> a piece of code inside a code block that already has <strong>syntax highlighting</strong>. I want to do this on a markdown file I have on Github that is hosted on Github Pages (can use kramdown markdown, html, css).</p>
  
  <p>I am aware that you can have <strong>syntax highlighting</strong> inside a code block doing something like this:</p>
  
  <pre><code>```java
  int foo (void) {
      int i;
  }
  ```
  </code></pre>
  
  <p>I am also aware that I can <strong>background highlight</strong> text inside a code block by doing something like this:</p>
  
  <pre><code>&lt;pre&gt;&lt;code&gt;int foo (void) {
      &lt;span style="background-color:yellow"&gt;int i;&lt;/span&gt;
  }
  &lt;/code&gt;&lt;/pre&gt;
  </code></pre>
  
  <p>But how do I combine these two things?</p>