fluidvideo.css

.fluid-width-video-wrapper {
   width: 100%;
   position: relative;
   padding: SET-BY-JAVASCRIPT% 0 0 0;
}

.fluid-width-video-wrapper iframe,
.fluid-width-video-wrapper object,
.fluid-width-video-wrapper embed {
   position: absolute;
   top: 0;
   left: 0;
   width: 100%;
   height: 100%;
}