Transitioning font-size and relative lengths

dabblet.css

/**
 * Transitioning font-size and relative lengths
 * See: http://lists.w3.org/Archives/Public/www-style/2011Nov/0016.html
 */


#inner, #outer {
   transition: 3s font-size, 1s width;
}

#outer {
   font-size: 20px;
   white-space: nowrap;
}

#outer:hover {
   font-size: 50px;
}

#inner {
   width: 5em;
   background-color: orange;
}

#inner:hover {
   width: 10em;
}

dabblet.html

<div id="outer">
   <div id="inner">
     Hover this
   </div>
</div>

settings.json

{"view":"split-vertical","fontsize":"100","seethrough":"","prefixfree":"1","page":"css"}