html,
body, main {
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background-color: black;
}

canvas {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}
/*
html,
body, main {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100vh;
  text-align: center;
  align-items: center;
  object-fit: contain;
  overflow: hidden;
  background-color: black;
}

canvas {
 margin: 0;
  padding: 0;
  text-align: center;
  align-items: center;
  max-width: 100%;
  max-height: 100vh;
  object-fit: contain;
  position:absolute;
  top: 0;
}
*/