 <p>Here are two examples of ways in which you could align a div in the middle:</p> <p>Using HTML:</p> <pre><code>&lt;div class="center" style="margin: 0 auto;"&gt;&lt;/div&gt; </code></pre> <p>Styling in a separate CSS file:</p> <pre><code>.center { margin: 0 auto; } </code></pre> <hr> <p>If you are making three columns and want them to resize according to the window width, you set the value of their width to be 33%. Here is an example:</p> <pre><code>.center { width: 33%; } .left { width: 33%; } .right { width: 33%; } </code></pre>