Of course they don't put their money where their mouth is and the document that ...

Of course they don't put their money where their mouth is and the document that describes this guideline itself doesn't follow it:

    <!DOCTYPE html>
    <html lang="en">
    <head>
    <meta charset="utf-8">
    <title>Google HTML/CSS Style Guide</title>
    <link rel="stylesheet" href="javaguide.css">
    <script src="include/styleguide.js"></script>
    <link rel="shortcut icon" href="https://www.google.com/favicon.ico">
    <script src="include/jsguide.js"></script>
    </head>
    <body onload="initStyleGuide();">
    [...]
    </body>
    </html>