html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
}
body {
  display: flex;
  align-items: center;
  justify-content: center;
  background-image: linear-gradient(
    to top,
    #f3e7e9 0%,
    #e3eeff 99%,
    #e3eeff 100%
  );
}
canvas {
  position: fixed;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
}

button {
  padding: 10px 20px;
  font-size: 24px;
}