Follow botton is not visible.. I can't understand.. help me

Tell us what’s happening:
// running tests
Your .follow-btn should be rendered on the page. Be sure to turn off any extensions such as ad blockers.
Your .follow-btn should have a display property set to flex
. // tests completed

  **Your code so far**

<style>
body {
  font-family: Arial, sans-serif;
}
header {
display: flex;
}
header .profile-thumbnail {
  width: 50px;
  height: 50px;
  border-radius: 4px;
}
header .profile-name {
display: flex;
  margin-left: 10px;
}
header .follow-btn {
  display: flex;
  margin: 0 0 0 auto;
}
header .follow-btn button {
  border: 0;
  border-radius: 3px;
  padding: 5px;
}
header h3, header h4 {
display: flex;
  margin: 0;
}
#inner p {
  margin-bottom: 10px;
  font-size: 20px;
}
#inner hr {
  margin: 20px 0;
  border-style: solid;
  opacity: 0.1;
}
footer {
display: flex;
}
footer .stats {
display: flex;
  font-size: 15px;
}
footer .stats strong {
  font-size: 18px;
}
footer .stats .likes {
  margin-left: 10px;
}
footer .cta {
  margin-left: auto;
}
footer .cta button {
  border: 0;
  background: transparent;
}
</style>
<header>
<img src="https://freecodecamp.s3.amazonaws.com/quincy-twitter-photo.jpg" alt="Quincy Larson's profile picture" class="profile-thumbnail">
<div class="profile-name">
  <h3>Quincy Larson</h3>
  <h4>@ossia</h4>
</div>
<div class="follow-btn">
  <button>Follow</button>
</div>
</header>
<div id="inner">
<p>I meet so many people who are in search of that one trick that will help them work smart. Even if you work smart, you still have to work hard.</p>
<span class="date">1:32 PM - 12 Jan 2018</span>
<hr>
</div>
<footer>
<div class="stats">
  <div class="Retweets">
    <strong>107</strong> Retweets
  </div>
  <div class="likes">
    <strong>431</strong> Likes
  </div>
</div>
<div class="cta">
  <button class="share-btn">Share</button>
  <button class="retweet-btn">Retweet</button>
  <button class="like-btn">Like</button>
</div>
</footer>
  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36.

Challenge: Add Flex Superpowers to the Tweet Embed

Link to the challenge:

have you tried deactivating the ad-blocker?