video {
  width: 100%;
  height: 100%;
}

html, body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: black;
}

#btn {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: black;
}

#btn img {
  max-width: 50vw;
  max-height: 50vw;
  cursor: pointer;
}