1. Save layout.css and advlayout.html.

    Reload advlayout.html in the browser.

    It should look like this:

  2. In layout.css, add formatting for the <body> tag:

    body {
    margin: 0;
    text-align: center;
    }
  3. Save layout.css, then reload advlayout.html in the browser.

    It should look like this: