body {
  font-family: sans-serif;
}

canvas {
  margin: 0 auto;
  display: block;
}

.flex-container {
  display: flex;
  flex-flow: row wrap;
  justify-content: space-around;
  padding: 1em;
  margin: 0;
}

.flex-item {
  width: 33vw;
  text-align: center;
}