body {
  margin: 0px;
   background: linear-gradient(midnightblue, black);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

canvas {
 background: linear-gradient(midnightblue, black);
  margin: 20px;
  border-radius: 15px;
  border: 5px solid rgb(255, 255, 255);    
}

img {
  display: none;
}