title: How can I put my header in top of everything?
body: <p>My header have the property &quot;position: fixed&quot;, but, some images in the body has the property &quot;filter: grayscale(100%)&quot;, when I scroll the page, the images are showed in front of my header.</p>
  <p>HTML:</p>
  <pre><code>&lt;header&gt;&lt;header&gt;
  &lt;img&gt;
  &lt;img&gt;
  &lt;img&gt;
  
  </code></pre>
  <p>CSS:</p>
  <pre><code>header{
      position: fixed;
  }
  
  img{
      filter: grayscale(100%);
  }
  </code></pre>
  <p>How can i put them behind my header?</p>