videogular2/docs/_book/gitbook/gitbook-plugin-responsive-iframes/plugin.css

Videogular is a video application framework for desktop and mobile powered by Angular 2.0

.intrinsic-container {
  position: relative;
  height: 0;
  overflow: hidden;
}

/* 16x9 Aspect Ratio */
.intrinsic-container-16x9 {
  padding-bottom: 56.25%;
}

/* 4x3 Aspect Ratio */
.intrinsic-container-4x3 {
  padding-bottom: 75%;
}

.intrinsic-container iframe {
  position: absolute;
  top:0;
  left: 0;
  width: 100%;
  height: 100%;
}