title: How to center to the screen a div content with Bootstrap 4
body: <p>I'm using Bootstrap 4 and I would like to <strong>center container content</strong>, which means it showing exactly on the center of the screen. However, my content is still stuck on the top side, even if height is 100% and I use <code>justify-content-center align-items-center</code></p>
  
  <p><strong>Image:</strong></p>
  
  <p><a href="https://i.stack.imgur.com/RZIk7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RZIk7.jpg" alt="enter image description here"></a></p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;!doctype html&gt;
  &lt;html lang="en" class="h-100"&gt;
  
  &lt;head&gt;
    ...
  &lt;/head&gt;
  
  &lt;body class="h-100"&gt;
  
    &lt;header&gt;
      ...
    &lt;/header&gt;
  
    &lt;main class="h-100"&gt;
  
      &lt;div class="container h-100"&gt;
  
        &lt;div class="row justify-content-center align-items-center"&gt;
          &lt;div class="col"&gt;
  
            &lt;!-- Title --&gt;
            &lt;div class="row text-center"&gt;
              &lt;div id="title" class="w-100 mt-5"&gt;
                &lt;h1&gt;Let's Find You a Great Apartment.&lt;/h1&gt;
              &lt;/div&gt;
            &lt;/div&gt;
  
            &lt;!-- Subtitle --&gt;
            &lt;div class="row text-center"&gt;
              &lt;div id="subtitle" class="w-100"&gt;
                &lt;h2&gt;&lt;small&gt;Join more than 5,828,476 happy renters searching 1,025,792 local apartments.&lt;/small&gt;&lt;/h2&gt;
              &lt;/div&gt;
            &lt;/div&gt;
  
            &lt;!-- Search box --&gt;
            &lt;div class="row w-100 align-items-center"&gt;
              &lt;div id="search" class="enterALocationSearchBox mt-2"&gt;
                &lt;input type="text" class="w-100" placeholder="Enter a Location here"&gt;
              &lt;/div&gt;
            &lt;/div&gt;
          &lt;/div&gt;
        &lt;/div&gt;
  
      &lt;/div&gt;
  
    &lt;/main&gt;
  
    &lt;!-- Optional JavaScript --&gt;
    &lt;!-- jQuery first, then Popper.js, then Bootstrap JS --&gt;
    &lt;script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous" /&gt;
    &lt;script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous" /&gt;
    &lt;script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous" /&gt;
  
  &lt;/body&gt;
  
  &lt;/html&gt;</code></pre>
  </div>
  </div>
  </p>