#osm{
[zoom > 17] { line-width: 0;  }
[zoom <= 17] { line-width: 10;  }
[zoom <= 16] { line-width: 7;  }
[zoom <= 15] { line-width: 5;  }
[zoom <= 14] { line-width:2;  }
[zoom <= 13] { line-width: 1.8;  }
[zoom <= 12] { line-width: 1.5;  }
[zoom <= 11] { line-width: 0;  }
}

