Vimeo iframe as background

Question

I going to make a website that has a video as a background.

I want to load the video from vimeo but I havent found the best way to put it fullscreen.

i´m trying to add a css to the iframe but it doesn´t work at all:

iframe{
     width: 100%;
     height: 100%;
}

Do any of you know the best way to embed it as a background without using plugins or html5 to avoid problems with IE.

thank you!

Solution

Here you go: Demo

Wrap it in a div and set that also to 100%, 100%

iframe, div {
     width: 100%;
     height: 100%;
}