<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Polymer Drive Viewer</title>
    <script src="bower_components/platform/platform.js"></script>
    <link rel="import" href="elements/drive-viewer.html">
    <style>
      * { box-sizing: border-box; }
      html, body { width: 100%; height: 100% }
      body {
        margin: 0;
        padding: 0;
      }
    </style>
  </head>
  <body>
    <drive-viewer clientId="YOUR_CLIENT_ID"></drive-viewer>
  </body>
</html>
<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, minimal-ui">
    <title>Polymer Drive Viewer</title>
    <script src="bower_components/platform/platform.js"></script>
    <link rel="import" href="elements/drive-viewer.html">
    <style>
      * { box-sizing: border-box; }
      html, body { width: 100%; height: 100% }
      body {
        margin: 0;
        padding: 0;
      }
    </style>
  </head>
  <body>
    <drive-viewer clientId="YOUR_CLIENT_ID"></drive-viewer>
  </body>
</html>

Add missing viewport for proper mobile display
Add missing viewport for proper mobile display