iFrame Play Button

<!doctype html>
<html>
  <head>
    <title>iframe Play Button</title>
    <style>
      @import "https://cdn.rawgit.com/mattborn/a9ceb96ad80f586cf40145276f98b86c/raw/713948588a471f22349744ff76d899fedbdb1577/bambu.css";
      iframe {
        border: none;
        max-width: 100%;
      }
      .video {
        height: 0;
        padding: 0 0 56.25%; /* 16:9 */
        position: relative;
      }
      .video-iframe,
      .video-play {
        height: 100%;
        left: 0;
        position: absolute;
        top: 0;
        width: 100%;
      }
      .video-play {
        align-items: center;
        color: white;
        cursor: pointer;
        font-size: 100px;
        display: flex;
        justify-content: center;
        pointer-events: none;
      }
      .video:hover .video-play { color: #11a7aa; }
    </style>
  </head>
  <body>
    <div class="video">
      <iframe class="video-iframe" src="https://www.facebook.com/video/embed?video_id=10154064015005318"></iframe>
      <div class="video-play">
        <i class="video-play-icon fa fa-youtube-play"></i>
      </div>
    </div>
    <script>
      focus();
      document.querySelectorAll('.video').forEach(function (el) {
        const listener = addEventListener('blur', function () {
          const play = el.querySelector('.video-play');
          if (play && document.activeElement === el.querySelector('.video-iframe')) {
            el.removeChild(play);
          }
          removeEventListener('blur', listener);
        });
      });
    </script>
  </body>
</html>