Can "embed-youtube" be styled with CSS

It appears when I place an embedded youtube video using the shortcode like this:

[youtube=http://www.youtube.com/watch?v=Xbk8wJTkiFs&w=480&h=360&rel=0]

An inline style is place on this video:

<span class='embed-youtube' style='text-align:center; display: block;'>

I’ve tried styling the class ’embed-youtube’ but it has no effect. Where does this inline styling come from. Wouldn’t it have been better to put this in a style sheet instead of inline? Is it possible to change this, do I have to dive into the php to find it? Seems awful clunky to add a div around it just to get it to flush left.