<style>
.video-container {
  position: relative;
  padding-bottom: 56.25%;
}

.video-container iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}
</style>
<div class="video-container">
  <iframe
    src="https://www.youtube.com/embed/msizPweg3kE"
    frameborder="0"
    allow="accelerometer; autoplay; encrypted-media; gyroscope;"
    allowfullscreen></iframe>
</div>