html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: #f0f0f0;
}

video {
  display: block;
  max-width: 100vw;
  max-height: 100vh;
  width: auto;
  height: auto;
  box-shadow: 0 4px 24px rgba(0,0,0,0.2);
  background: #222;
}