// writing-mode wm
$writing-mode : (
  ( vals: (
    'rl' : rl,
    'vtb': vertical-tb,
    'vlr': vertical-lr,
  ),),
  ( vals: (
    'lr' : lr,
    'rl' : rl,
    'vtb': vertical-tb,
    'vlr': vertical-lr,
  ), bp: $bp-800w-mx,),
  ( vals: (
    'lr' : lr,
    'rl' : rl,
    'vtb': vertical-tb,
    'vlr': vertical-lr,
  ), bp: $bp-600w-mx,),
);