iFrame

HTML

<div class="iframe-video">
  <iframe width="600" height="600" src="https://www.credencys.com"></iframe>
</div>

CSS

.iframe-video {
  position: relative;
  padding-bottom: 56.25%;
  padding-top: 0px;
  overflow: hidden;
  margin-top: 40px;
}

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