text: $x: a, b, 1+2;
  
  @if type-of(nth($x, 3)) == number {
    div {
      background: gray;
    }
  }
  
  @if type-of(nth($x, 2)) == number {
    div {
      background: gray;
    }
  }
  @else if type-of(nth($x, 2)) == string {
    div {
      background: blue;
    }
  }
  
  @if type-of(nth($x, 2)) == number {
    div {
      background: gray;
    }
  }
  @else if type-of(nth($x, 2)) == color {
    div {
      background: blue;
    }
  }
  @else {
    div {
      background: red;
    }
  }