Mediaelement in Core – this responsive code doesn't work?

I have been playing around with the video in WP3.6 core and have read various threads.

I have set up a wrapper as indicated on other threads that scales to full width and height. Within that I am playing the video.

The first piece of HTML works fine. But when I use the shortcode for WordPress:

do_shortcode(‘[video webm="http://localhost/dnp/stalker.webm" width=100%]‘);

It doesn’t scale…. I have tried width=100%, height=100% and combinations thereof.

What am I missing?

—-

CSS:

.videocontent {
width: 100%;
height: 100%;
max-width: 1024px;
margin: 0 auto;
}

—-
HTML

<div class=”videocontent”>

<!– Using HTML5 scales perfectly 🙂 –>
<video id=”myvideo2″ style=”width:90%;height:100%;” controls=”controls”>
<!– Just a webm file for firefox –>
<source src=”http://localhost/prototypes/mediaelement/stalker.webm&#8221; type=”video/webm”/>
</video>

<!– This doesn’t 🙁 –>
<?php
echo do_shortcode(‘[video webm="http://localhost/dnp/stalker.webm" width=100%]‘);
?>

</div>