title: Flexbox 2x2 grid - input inside overflows the flex container
body: <p>I want to have a flexbox 2x2 grid that contain a random number of elements (odd or even). I've achieved to create this flexbox without any problems. </p>
  
  <p>When I added my content: input fields with width 100% I noticed that those are bigger then their flex container which seems odd. In the example this is easy to spot on the last red box.</p>
  
  <p>How can I make the input fields be 100% of the flex container?</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>.flex-grid {
    display: flex;
    flex-wrap: wrap;
    height: 500px;
  }
  .grid-item {
    flex: 1 1 50%;
    background: #F90;
    border-top: solid 1px #000;
  }
  .grid-item:nth-child(odd) {
    background: #F00;
    flex: 0 0 50%;
  }
  
  input {
    width: 100%;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="flex-grid"&gt;
    &lt;div class="grid-item"&gt;
      &lt;input type="text" value="email"&gt;
    &lt;/div&gt;
    &lt;div class="grid-item"&gt;
      &lt;input type="text" value="email"&gt;
    &lt;/div&gt;
    &lt;div class="grid-item"&gt;
      &lt;input type="text" value="email"&gt;
    &lt;/div&gt;
  
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>Fiddle: <a href="https://jsfiddle.net/x3pyenkL/" rel="nofollow noreferrer">https://jsfiddle.net/x3pyenkL/</a></p>