.wrapper {
  width: 960px;
}

.green-bg {color: yellow;
  background-color: green;
}

.yellow-bg {
  background-color: yellow;
}

.blue-fg {
  color: blue;
  background-color: pink;
}

.box {
  border: 1px solid purple;
  width: 300px;
  height: 100px;
  margin: 5px;
  border-radius: 15px;
}