<h1>Fixed-width design</h1>
<article>
  <p>If you specify a fixed width for your layout, then your layout will only look good at that specific width. If a visitor to your site has a screen that is wider than the width you have specified, then there’ll be wasted space on the screen. You can center the content of your pages to distribute that space more evenly (instead of having empty space on one side) but you still wouldn’t be taking full advantage of the available space.</p>
  <p>Similarly, if the visitor arrives with a screen that is narrower than the width you’ve chosen, then your content won’t fit horizontally. The browser generates a crawlbar—the horizontal equivalent of a scrollbar—and the user has to move the whole page left and right in order to see all of the content.</p>
</article>

body {
  width: 640px;
  font-family: sans-serif;
  line-height: 1.5;
  padding: 0 16px;
}

h1 {
  margin-bottom: 0;
}