* {
  box-sizing:border-box;
  transition: all .33s ease-in-out;
}

body {
  margin: 0;
}

canvas {
  display: block;
}

#menu {
  position: absolute;
  margin: 1em;
  padding: 1em;
  background: rgba(0,0,0,.7);
  color: white;
}

#buttons {
  display: flex;
  flex-direction: column;
}

.hidden {
  opacity: 0;
}