title: How do I use the Spacing Utility Classes in Bootstrap
body: <p>In this <a href="https://scotch.io/bar-talk/whats-new-in-bootstrap-4" rel="noreferrer">article</a> I saw Bootstrap 4 Spacing Utility Classes, and he uses <code>m-b-lg</code> in <code>className</code>.</p>
  
  <pre><code>&lt;div class="row"&gt;
      &lt;div class="col-sm-6 m-b-lg"&gt;
          &lt;!-- column-small-50%, margin-bottom-large --&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>But when I use it on meteorjs with react nothing happens. Am I missing something or missing a plugin?</p>
  
  <pre><code>&lt;div className="container-fluid"&gt;
      &lt;div className="col-xs-6 col-xs-offset-3 m-t-lg"&gt;
          &lt;h1 className="text-xs-center"&gt; Login &lt;/h1&gt;
          &lt;form&gt;
              &lt;div className="form-group"&gt;
                  &lt;input type="email" className="form-control" id="inputEmail" placeholder="Email"/&gt;
              &lt;/div&gt;
              &lt;div className="form-group"&gt;
                  &lt;input type="password" className="form-control" id="inputPassword" placeholder="Password"/&gt;
                  &lt;p className="text-xs-center"&gt;&lt;a href="/signup"&gt; Forgot your email or password?&lt;/a&gt;&lt;/p&gt;
              &lt;/div&gt;      
              &lt;div className="form-group"&gt;
                  &lt;button className="btn btn-primary btn-block" type="submit"&gt; Login &lt;/button&gt;
                  &lt;p className="text-xs-center"&gt; New to Arcademy? &lt;a href="/signup"&gt; Sign up now.&lt;/a&gt;&lt;/p&gt;
              &lt;/div&gt;
          &lt;/form&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>