[css] youtube影片設計iframe RWD (iframe RWD with youtube iframe video)

1、css：

.video-container {
    position: relative;
    padding-bottom: 56.25%;
    padding-top: 30px; height: 0; overflow: hidden;
}
.video-container iframe,
.video-container object,
.video-container embed {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

html結構：

參考資料：Responsive Youtube Embed