gistfile1.txt

#admin {
  line-join: round;
  line-color: mix(#d14, #fff, 40);
  [maritime=1][zoom>=0] { line-color: @water; }
  // Countries
  [admin_level=2] {
    line-width: 1;
    [zoom>=4] { line-width: 1.4; }
    [zoom>=6] { line-width: 2; }
    [zoom>=8] { line-width: 4; }
    [disputed=1] { line-dasharray: 4,4; }
  }
  // States / Provices / Subregions
  [admin_level>=3] {
    a/line-color: mix(@rt_dark, @land, 50);
    a/line-width: 0.4;
    a/line-dasharray: 8,2;
    [zoom>=4] { a/line-width: 0.8; }
    [zoom>=6] { a/line-width: 1; }
    [zoom>=8] { a/line-width: 2; }
    [zoom>=12] { a/line-width: 3; }
    
    b/line-color: yellow;
    b/line-width: 2;
    [zoom>=4] { b/line-width: 2.4; }
    [zoom>=6] { b/line-width: 2.8; }
    [zoom>=8] { b/line-width: 3; }
    [zoom>=12] { b/line-width: 3.2; }
  }
}