reduceSpaces(decl) {
    let stop = false
    this.prefixes.group(decl).up(() => {
      stop = true
      return true
    })
    if (stop) {
      return
    }

    let parts = decl.raw('before').split('\n')
    let prevMin = parts[parts.length - 1].length
    let diff = false

    this.prefixes.group(decl).down(other => {
      parts = other.raw('before').split('\n')
      let last = parts.length - 1

      if (parts[last].length > prevMin) {
        if (diff === false) {
          diff = parts[last].length - prevMin
        }

        parts[last] = parts[last].slice(0, -diff)
        other.raws.before = parts.join('\n')
      }
    })
  }
Normalize spaces in cascade declaration group