title: CSS - change the style of another element when a link is hovered?
body: <p>How can I change the style of another element when a link is hovered - without jQuery/ JavaScript?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>ul&gt;li&gt;a:hover main {
    opacity: 0.1;
  }
  
  main p {
    font-size: 200px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;header&gt;
    &lt;ul&gt;
      &lt;li&gt;&lt;a href="#"&gt;Hover me&lt;/a&gt;&lt;/li&gt;
    &lt;/ul&gt;
  &lt;/header&gt;
  
  &lt;main&gt;
    &lt;p&gt;Hello World!&lt;/p&gt;
  &lt;/main&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>I want to change the <code>opacity</code> of the text in <code>main</code> when the link is hovered.</p>
  
  <p>Is it possible?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>I tried with a sibling:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>a:hover ul {
    opacity: 0.5;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;header&gt;
    &lt;ul&gt;
      &lt;li&gt;&lt;a href="#"&gt;Hover me&lt;/a&gt;&lt;span&gt;&lt;/span&gt;
        &lt;ul&gt;
          &lt;li&gt;Child 1&lt;/li&gt;
          &lt;li&gt;Child 2&lt;/li&gt;
          &lt;li&gt;Child 3&lt;/li&gt;
        &lt;/ul&gt;
      &lt;/li&gt;
    &lt;/ul&gt;
  &lt;/header&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>But still does not work...</p>