section.red.background {
  background-color: red;
}

section.green {
  background-color: green;
}

section.blue.canvas {
  background-color: blue;
}

/* font example */
@import 'https://fonts.googleapis.com/css?family=Baloo+Bhai';
section.topic h2,
section.topic div p {
    font-family: 'Baloo Bhai', cursive;
}