<!DOCTYPE html>
<html>
    <head>
        <title>HTML centering</title>
        <style type="text/css">
        html, body, #tbl_wrap {
            height: 100%;
            width: 100%;
            padding: 0;
            margin: 0;
        }
        #td_wrap {
            vertical-align: middle;
            text-align: center;
        }
        body {
            background-color: {{color}};
        }
        </style>
    </head>
    <body>
        <table id="tbl_wrap">
            <tbody>
                <tr>
                    <td id="td_wrap">
                        <iframe id="ytplayer" type="text/html"
                                width="{{width}}" height="{{height}}"
                                src="http://www.youtube.com/embed/{{uri}}?autoplay=1&origin=http://anaconda.org""
                                frameborder="0"/>            
                    </td>
                </tr>
            </tbody>
        </table>
    </body>
</html>