title: List CSS custom properties (CSS Variables)
body: <p>I've set some CSS custom properties in my stylesheet:</p>
  
  <pre><code>:root {
      --bc: #fff;
      --bc-primary: #eee;
      --bc-secondary: #ddd;
  }
  </code></pre>
  
  <p>I can retrieve them individually if I already know the name of the CSS variable like so:</p>
  
  <pre><code>console.log(getComputedStyle(document.body).getPropertyValue('--bc'));
  
  // #fff
  </code></pre>
  
  <p>But if I wanted to pull a list of CSS variables and their values out, how would that be done?</p>