html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  margin: 0;
}

#container {
  width: 50%;
  height: 50%;
}

.button {
  position: absolute;
  left: 10px;
  padding: 1rem;
}

#controlButton {
  top: 1rem;
}

#modeButton {
  top: 4rem;
}

#videoButton {
  top: 150px;
  display: none;
}