title: table-responsive in bootstrap 4 doesn't work
body: <p>i'm beginner who just started</p>
  
  <p>i've tried to following video of creating forum using bootstrap 4 in <a href="https://youtu.be/4_YQ6efCyW8" rel="nofollow noreferrer">youtube</a></p>
  
  <p>but table-responsive doesn't work</p>
  
  <p>i think my code is same as in video but browser not the same</p>
  
  <p><a href="https://drive.google.com/open?id=15TtURhBr6zzY1B0u020NsE_qu3WqtZsu" rel="nofollow noreferrer">my broswer</a></p>
  
  <p><a href="https://drive.google.com/open?id=1mCoi3X1Oa1oBvDti9l4xNXFcV5LqAenp" rel="nofollow noreferrer">browser in youtube</a></p>
  
  <p>here's my table. i hope someone help me.. </p>
  
  <p>thanks</p>
  
  <pre><code>&lt;table class="table table-striped table-bordered table-responsive"&gt;
      &lt;thead class="thead-light"&gt;
          &lt;tr&gt;
              &lt;th scope="col" class="forum-col"&gt;Forum&lt;/th&gt;
              &lt;th scope="col"&gt;Topics&lt;/th&gt;
              &lt;th scope="col"&gt;Posts&lt;/th&gt;
              &lt;th scope="col" class="last-post-col"&gt;Last post&lt;/th&gt;
          &lt;/tr&gt;
      &lt;/thead&gt;
  
      &lt;tbody&gt;
          &lt;tr&gt;
              &lt;td&gt;
                  &lt;h3 class="h5"&gt;&lt;a href="#0"&gt;Forum name&lt;/a&gt;&lt;/h3&gt;
                  &lt;p&gt;ddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd&lt;/p&gt;
              &lt;/td&gt;
              &lt;td&gt;
                  &lt;div&gt;5&lt;/div&gt;
              &lt;/td&gt;
              &lt;td&gt;
                  &lt;div&gt;18&lt;/div&gt;
              &lt;/td&gt;
              &lt;td&gt;
                  &lt;h4 class="h6"&gt;&lt;a href="#0"&gt;Post name&lt;/a&gt;&lt;/h4&gt;
                  &lt;div&gt;by &lt;a href="#0"&gt;Author name&lt;/a&gt;&lt;/div&gt;
                  &lt;div&gt;05 Apr 2017, 20:07&lt;/div&gt;
              &lt;/td&gt;
          &lt;/tr&gt;
       &lt;tbody&gt;
  </code></pre>