title: set size to responsive iframe in bootstrap
body: <p>Is it possible to set a size to an inframe in bootstrap? </p>
  
  <p>I set up the iframe like this: </p>
  
  <pre><code>&lt;div class="embed-responsive embed-responsive-16by9"&gt;
    &lt;iframe class="embed-responsive-item" src="…"&gt;&lt;/iframe&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And I tried to set a maximum height to 450 px with this:</p>
  
  <pre><code>.embed-responsive {
     max-height:450px;
  }
  </code></pre>
  
  <p>This had no effect at all. Can you give me a hint, how could achieve a smaller but still responsive iframe?</p>