.btn {
  &:hover {
    color: red;
  }

  &:active {
    color: blue;
  }

  &:nth-child(5n+1) {
    color: blue;
  }

  &:nth-child(-n+3) {
    color: green;
  }

  > li > a {
    color: red;
  }

  > li > li {
    color: blue;
  }

  > p + p {
    color: green;
  }
}