title: CSS background color center
body: <p>I would like to center the image automatically,I do not want to use left and top
  I want to establish what the center,</p>
  
  <pre><code>    &lt;style&gt;
  #loading{
          position:absolute;
          background-color: #6B718B;
          font:40px Arial, Helvetica, sans-serif;
          color:#ffffff;
          padding:20px;
          border-radius: 10px;
          opacity:0.5;
  
  }
  &lt;/style&gt;
  &lt;div id="loading"&gt;Loading...&lt;/div&gt;
  </code></pre>
  
  <p>thanks</p>