.videoWrapper {
  margin: auto;
  width: 80%;
  max-width: 800px;
  position: relative;
  padding-top: min(450px, calc(56.25% * 0.8)); /* 16:9 */
  margin-bottom: 10px;
  height: 0;  
}

.videoWrapper:before {
}

iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;  
  border-radius: 20px;
}