title: DIV - exact center of page
body: <p>I need to place a div exactly in the middle of the page with an unknown width and height. I can get it centered with the width but is it possible to get it centered with the height?</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;div class='lightbox'&gt;
      &lt;div class='tc-content'&gt;AAA&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>CSS </p>
  
  <pre><code>.lightbox { 
      position: fixed;
      top: 0px;
      left: 0px;
      width: 100%;
      height: 100%;
      background: #000;
      text-align: center;
  }
  
  .tc-content {
      display: inline-block;
  }
  </code></pre>