Error: "You should use an h2 CSS selector to change the font."

The system is throwing me this error: You should use an h2 CSS selector to change the font.
But, I don’t know why. Please help.
By the way, sorry if I have an bad english, it isn’t my native language.

<link href="https://fonts.googleapis.com/css?family=Lobster" rel="stylesheet" type="text/css">


<style>

  p {
    font-size: 16px;
    font-family: monospace;
  }

  h2 {
    font-family: 'Lobster';
  }
</style>

<h2 class="h2">CatPhotoApp</h2>
<main>
  <p class="red-text">Click here to view more <a href="#">cat photos</a>.</p>

  <a href="#"><img src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back."></a>

  <div>
    <p>Things cats love:</p>
    <ul>
      <li>cat nip</li>
      <li>laser pointers</li>
      <li>lasagna</li>
    </ul>
    <p>Top 3 things cats hate:</p>
    <ol>
      <li>flea treatment</li>
      <li>thunder</li>
      <li>other cats</li>
    </ol>
  </div>

  <form action="https://freecatphotoapp.com/submit-cat-photo">
    <label><input type="radio" name="indoor-outdoor" checked> Indoor</label>
    <label><input type="radio" name="indoor-outdoor"> Outdoor</label><br>
    <label><input type="checkbox" name="personality" checked> Loving</label>
    <label><input type="checkbox" name="personality"> Lazy</label>
    <label><input type="checkbox" name="personality"> Energetic</label><br>
    <input type="text" placeholder="cat photo URL" required>
    <button type="submit">Submit</button>
  </form>
</main>

remove the class h2 declaration from the h2 tag and let’s know what happens

oh, thanks! it works!

Sure thing. Keep moving!