title: How to fit two inline elements to the body width?
body: <pre><code>&lt;html&gt;
  
  &lt;head&gt;
  &lt;title&gt;Title&lt;/title&gt;
  &lt;style type="text/css"&gt;
  
  #container {
      position: relative;
  }
  #line {
      border-bottom: thin solid gray;
      display:inline-block;
      position:relative;
      bottom: 1ex;
      width:90%;
  }
  &lt;/style&gt;
  &lt;/head&gt;
  
  &lt;body&gt;
  &lt;div id="container"&gt;
      &lt;span id="title"&gt;Title&lt;/span&gt;
      &lt;span id="line"&gt;&lt;/span&gt;
  &lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>How do i make that the width of span "line" to be equal with
  the width of "container" minus width of the span "title"?</p>
  
  <p><strong>Edit</strong></p>
  
  <p>The width of the "title" to be decided by the text inside the "title".</p>