Apply the flex-direction Property to Create Rows in the Tweet Embed - not sure what this challenge is for

Tell us what’s happening:
Not sure what this challenge is all about. Adding the code flex-direction: row; to both header and footer did not change the display at all.

Your code so far


<style>
  body {
    font-family: Arial, sans-serif;
  }
  header {
    display: flex;
    flex-direction: row;
  }
  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;
    flex-direction: row;
  }
  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://pbs.twimg.com/profile_images/378800000147359764/54dc9a5c34e912f34db8662d53d16a39_400x400.png" 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 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.80 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/responsive-web-design/css-flexbox/apply-the-flex-direction-property-to-create-rows-in-the-tweet-embed

The layout doesn’t change because flex-direction: row is the default. It is implicitly set by display: flex on the two elements.

Not really sure why the challenge was made the way is it without mentioning it being the default.