What we really need to do is to wrap the entire content in a div tag; so let's do that. Go into the HTML file. In the line beneath the opening section tag, add <div class="wrapper"> . And right before the closing section tag, close it with </div>:
<section class="secondary-section">
<div class="wrapper"> <div>...</div> <div>...</div> <div>...</div> </div> </section>
Now, switch over to the CSS file. The .wrapper tag is going to be a more reusable class. To center any element, we'll give it a margin, and we'll use the two-value syntax: top and bottom are going to be zero, and left and right are going to be auto. We also have to give it a width of 960px. Without a width, you really can't center it using this margin technique: ...
