html,
body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  background: #292929;
  background: radial-gradient(
    circle,
    rgba(41, 41, 41, 1) 0%,
    rgba(0, 0, 0, 1) 80%,
    rgba(0, 0, 0, 0) 100%
  );
  background: -moz-radial-gradient(
    circle,
    rgba(41, 41, 41, 1) 0%,
    rgba(0, 0, 0, 1) 59%,
    rgba(0, 0, 0, 0.9864320728291317) 100%
  );
  background: -webkit-radial-gradient(
    circle,
    rgba(41, 41, 41, 1) 0%,
    rgba(0, 0, 0, 1) 59%,
    rgba(0, 0, 0, 0.9864320728291317) 100%
  );
}
canvas {
  display: block;
  border-radius: 25px;
}