Flexbox not working in Internet Explorer 11
<p>This piece of code works fine in Firefox, Chrome and Edge, but it does not work properly in IE11 because of flex model, apparently. How can I fix it?</p>

<p><strong>This is how it looks in Firefox</strong></p>

<p><a href="https://i.stack.imgur.com/BJgVt.png" rel="noreferrer"><img src="https://i.stack.imgur.com/BJgVt.png" alt="enter image description here"></a></p>

<p><strong>This is how it looks in IE11</strong></p>

<p><a href="https://i.stack.imgur.com/Fedul.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Fedul.png" 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-css lang-css prettyprint-override"><code>body * {
  box-sizing: border-box;
}
html {
  height: 100%;
}
body {
  min-height: 100%;
  display: flex;
  flex-flow: column;
  margin: 0;
}
main {
  flex: 1;
  display: flex;
}
header,
footer {
  background: #7092BF;
  border: solid;
  width: 100%;
}
section {
  border: solid;
  background: #9AD9EA;
  flex: 1
}
aside {
  border: solid;
  width: 150px;
  background: #3E48CC
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;header&gt;
  &lt;p&gt;header
&lt;/header&gt;
&lt;main&gt;
  &lt;aside&gt;
    &lt;p&gt;aside
    &lt;p&gt;aside
  &lt;/aside&gt;
  &lt;section&gt;
    &lt;p&gt;content
    &lt;p&gt;content
    &lt;p&gt;content
    &lt;p&gt;content
  &lt;/section&gt;
&lt;/main&gt;
&lt;footer&gt;
  &lt;p&gt;footer
  &lt;p&gt;footer
&lt;/footer&gt;</code></pre>
</div>
</div>
</p>