body {
  padding: 0;
  margin: 0;
  width: 100vw;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

canvas {
  position: absolute;
}

.topcorner {
    position: absolute;
    align-items:center;
    justify-content: center;
}