body {
  margin: 0px;
  background: darkslategray;
}

div#container {
  display: flex;
  justify-content: center;
  align-content: center;
  height: 100vh;
}

canvas#raven {
  height: 100%;
  max-width: 100%;
  max-height: 100%;
}

canvas#raven:focus, canvas#raven:focus-visible {
  outline: none;
}