title: css calc function: How to calculate width of text?
body: <p>Let's say that I have the following html template: </p>
  
  <pre><code>&lt;div id="container"&gt;
     &lt;h2&gt; Name &lt;/h2&gt; &lt;input type="text"&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>and I want that the width of 'input' will be equal to the width of container - the width of text inside 'h2'. How can I do it? </p>