title: Bootstrap 4 responsive spacing (padding) not working
body: <p>I want to give certain top-bottom padding of 80px and left-right padding of 0 inside my parent div id (about-us). So I've tried bootstrap 4 responsive spacing (padding) i.e. py-80 but it's not working here with me.</p>
  
  <pre><code>&lt;div id="about-us" class="py-md-80"&gt;
    &lt;div class="container text-center"&gt;
      &lt;h3 class="display-5 text-capitalize"&gt;about us&lt;/h3&gt;
      &lt;p class="text-muted"&gt;Divide have don't man wherein air fourth. Own itself 
       make have night won't make. 
       A you under Seed appear which good give. Own give air without fowl move the 
       dry first 
      heaven fruit, dominion she'd won't very all.&lt;/p&gt;
      &lt;img src="./imgs/signature.jpg" alt="signarure" class="img-responsive"&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>