Can't get background center on top, nor fullscreen - css

Question

What I want is for the background video to fit the screen lengthwise(y) and crop sides widthwise(x) when less than the ratio. As it is now, when someone is looking at in in a long skinny browser, half the video gets cut off on the right rather than both sides being shrunk and centered on the middle. Alternatively I would like the whole thing to stretch in every direction and fit the browser, but I've also searched every page about that and none of the commands seem to work... I dunno maybe less has a new command, but I can't find it...
I am editing the .less file to accomplish what I need and almost all of the css commands seem to work except the one I need or at least, not anywhere I've tried putting it... still not sure what the difference between css and less is aside from newer/better. Here's what I have, it's the best I've found so far. it shrinks to the middle at least when it gets small:
// Background
#rt-top-surround {
position: relative;
video {
position: fixed;
width: auto;
height: 100%;
min-width: 100%;
-webkit-background-size: cover; }
-moz-background-size: cover; } these do nothing at all
-o-background-size: cover; } neither does background-size: 100%;
background-size: cover; }
.backface-visibility(hidden);
}
No matter what I do I can't stop it from preserving the aspect ratio. Any help for either full screen or centering the background video will do. Thanks in advance
-Scott
(I have only been teaching myself how to program websites over the last 2 days so I may not understand everything you say. Please keep that in mind. However, I did program and re-write a site from a template since then and I have been through every single file on ftp and read through the css just to learn what I can. I actually know a pretty decent amount)

Answer 1

You starters your CSS is invalid, #rt-top-surround isn't closed off so anything under that is broken.
// Background
#rt-top-surround {
position: relative;
} /* <------ here! */
As for background-size, this only applies to background-image not a video element. You can simply set width to whatever you want and because height:auto is applies be default it was scale with aspect ratio.
jsFiddle
HTML
<video>
<source src="http://www.quirksmode.org/html5//videos/big_buck_bunny.mp4" type="video/mp4"></source>
</video>
CSS
video {
width:100%;
}