ニコニコ動画のコード

[[module css]]
.embed-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    max-width: 100%;
} 
 
.embed-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}
[[/module]]

[[div class="embed-container"]]
[[embedvideo_]]
<iframe src="https://embed.nicovideo.jp/watch/sm30540673" scrolling="no" frameborder="0" allowfullscreen></iframe>
[[/embedvideo]]
[[/div]]

参照できるサイト：https://blog.hayu.io/web/create/nicovideo-embed-player-api