title: How do I automatically resize input fields in a form?
body: <p>I'm trying to make my registration form responsive for mobile devices but I got a little problem with the resizing of my input fields,</p>
  
  <p>I made a jsfiddle to show the situation:
  <a href="https://jsfiddle.net/ntvrhLpe/" rel="nofollow">https://jsfiddle.net/ntvrhLpe/</a></p>
  
  <p>I would like that if the width is smaller than 540px the input fields automatically resize to full width with a margin of 10px at both sides.</p>
  
  <p>I already tried some things but nothing works:</p>
  
  <pre><code>input[type=text], input[type=password], input[type=email]{
  margin-left:10px;
  margin-right:10px;
  width:100%;
  }
  </code></pre>
  
  <p>Can someone help me?</p>