with-postcss-nested.input.css

main section {
  &.modifier {
    @dark {
      color: white;
    }
  }

  > ul, .another-list {
    @dark {
      color: black;
    }
  }
  @media (min-width: 768px) {
    ul {
      @light {
        color: white;
      }
    }
  }
}