$map-sizing: (
  w: (
    is-responsive: true,
    default: false,
    modifiers: (
      100: (
        width: 100%
      ),
      75: (
        width: 75%
      ),
      50: (
        width: 50%
      ),
      25: (
        width: 25%
      )
    )
  ),
  h: (
    is-responsive: true,
    default: false,
    modifiers: (
      100: (
        height: 100%
      ),
      75: (
        height: 75%
      ),
      50: (
        height: 50%
      ),
      25: (
        height: 25%
      )
    )
  )
);