title: Flex with overflow and bootstrap navbar bevahes differently in Firefox/Chrome/Safari
body: <p>When I use Firefox to display the snippet below, the <code>div</code> with class <code>h-100</code> is assigned the full page height (<code>100vh</code>), and the height of the <code>nav</code> is then added so that a second scroll bar is produced.</p>
  
  <p>What I want is that only the <code>div</code> with <code>overflow-y: auto</code> should have a scroll bar.</p>
  
  <p>The strange thing about this is that the code seems to behave as I want in Chrome and Safari.</p>
  
  <p>Is there a problem with my HTML/CSS, and how can I work around this difference in behaviors?</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-css lang-css prettyprint-override"><code>.grey {
    background-color: grey;
  }
  
  #foo {
    background-color: red;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet"/&gt;
  
  &lt;div id="root"&gt;
    &lt;div style="height: 100vh; display: flex; flex-direction: column"&gt;
      &lt;nav class="navbar navbar-dark navbar-expand bg-dark"&gt;&lt;a class="navbar-brand" href="/"&gt;Title&lt;/a&gt;&lt;/nav&gt;
      &lt;div class="h-100" style="display: flex; flex-direction: row"&gt;
        &lt;div style="flex: 1 1 auto; overflow-y: auto"&gt;
          &lt;div id="foo" style="height: 1200px"&gt;
          &lt;/div&gt;
        &lt;/div&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>