body {
  color: transparent;
  background-color: transparent;
  font-family: sans-serif;
  overflow: hidden;

  display: flex;
  justify-content: center;
  align-items: center;

  --bodymargin: 1vh;
  --wContent: calc(100vw - 2*var(--bodymargin));
  --hContent: calc(100vh - 2*var(--bodymargin));
  margin: 0;
  padding: 0;
  height: 100vh;
}

canvas
{
  max-height: calc(min(var(--wContent), var(--hContent)));
  max-width: calc(min(var(--wContent), var(--hContent)) * 4/5);
  box-shadow: 1px 1px 2px 2px rgba(33, 33, 33, .2);
}