css/css-layout/practical-positioning-examples/hidden-info-panel-start.html

<!DOCTYPE html>
<html lang="en-US">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width" />
    <title>Hidden info panel</title>

    <style></style>
  </head>
  <body>
    <label for="toggle">❔</label>
    <input type="checkbox" id="toggle" />
    <aside>
      <h2>Information</h2>

      <p>Some very important information about your app:</p>

      <ol>
        <li>It has a really cool slide-out information box.</li>
        <li>
          This information box uses a combination of fixed positioning and a CSS
          transition for the smooth sliding.
        </li>
        <li>
          It also uses a cool technique called the
          <a href="https://css-tricks.com/the-checkbox-hack/">checkbox hack</a>.
        </li>
        <li>
          This allows you to create a nice "toggle on/toggle off" UI effect
          without using any JavaScript, which will work in IE9 and above (the
          smooth transition will work in IE10 and above.)
        </li>
      </ol>
    </aside>
  </body>
</html>