title: How to set the width of background-color of a div?
body: <p>I have two divs with same background color. How can I set the width of background?</p>
  <p><strong>Expected result</strong>:</p>
  <p><img src="https://i.stack.imgur.com/NjaUy.png" alt="enter image description here" /></p>
  <p>Here is HTML:</p>
  <pre><code>&lt;div&gt;
      &lt;span&gt;100% width of background&lt;/span&gt;
  &lt;/div&gt;
  &lt;div&gt;
      &lt;span&gt;75% width of background&lt;/span&gt;
  &lt;/div&gt;
  </code></pre>
  <p>What I tried to do using CSS:</p>
  <pre><code>div {
      background-color: #fc0;
      margin: 2px;
  }
  div:last-child {
      background-size: 75%;
  }
  </code></pre>
  <p><a href="http://jsfiddle.net/samosfator/3acGS/" rel="nofollow noreferrer">jsFiddle</a>, of course.</p>
  <p><em><strong>Is it posible to do this exept of setting <code>width</code> of a <code>div</code>?</strong></em></p>