* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: #111;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  overflow: hidden;
}

canvas {
  width: 95vw;
  height: 95vh;
  display: block;
  background: #222;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0,0,0,0.5);
}