* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  display: flex;
  background: #17193a;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-family: Arial, sans-serif;
}

canvas {
  background-color: #fff;
}

.flex {
  display: flex;
}

.color {
  margin-top: 1rem;
  width: 100px;
  height: 100px;
  background-color: #fff;
}

.red {
  background-color: #f00;
}

.green {
  background-color: #0f0;
}

.blue {
  background-color: #00f;
}