html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background: #000;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

video {
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
  border: none;
  background: #000;
  display: block;
  object-fit: contain; /* ou 'cover' se preferir */
}