title: SCSS extend a nested selector and override the nested rulesets
body: <p>Ok so I have a placeholder with a nested selector:</p>
  
  <pre><code>%block {
    .title {
      font-size:12px;
    }
  }
  </code></pre>
  
  <p>I want to extend it and ADD to the <code>.title</code> class:</p>
  
  <pre><code>.superblock {
    @extend %block;
    .title {
      font-weight:bold;
    }
  }
  </code></pre>
  
  <p>The answer I WANT is this:</p>
  
  <pre><code>.superblock .title {
    font-size: 12px;
    font-weight: bold; }
  </code></pre>
  
  <p>However, the answer I get is this:</p>
  
  <pre><code>.superblock .title {
    font-size: 12px; }
  
  .superblock .title {
    font-weight: bold; }
  </code></pre>
  
  <p>Am I doing something wrong or is this just how it works? To clarify I want to merge it. If I add something directly inside the <code>.superblock</code> and add like another <code>.superblock2</code> which also extends %block they merge without any problems.</p>