$utilities: map-merge(
  $utilities,
  (
    "letter-spacing": (
      property: letter-spacing,
      class: tracking,
      variants: letter-spacing,
      values: (
        "tighter": -0.05em,
        "tight": -0.025em,
        "normal": 0em,
        "wide": 0.025em,
        "wider": 0.05em,
        "widest": 0.1em,
      ),
    ),
  )
);