button {
  padding: 1.5em;
  margin: 1.5em;
}

@media (orientation: landscape) {

  main {
    display: flex;
    flex-direction: row;
  }

  canvas {
    height: 100%;
  }

  nav {
    align-content: center;
  }

}

@media (orientation: portrait) {

  main {
    display: flex;
    flex-direction: column;
  }

  canvas {
    width: 100%;
    height: 75%;
  }

  nav {
    width: 100%;
    align-content: center;
  }

}