Use this SASS class to make your video embeds responsive.

responsive_video_embed.scss

.video-embed {
  position: relative;
	padding-bottom: 56.25%; // a 16x9 video's height is 56.25% of its width
	height: 0;
	object, embed, iframe {
		position: absolute;
		top: 0;
		left: 0;
		width: 100%;
		height: 100%;
	}
}