class Sass::CSS

def nest_seqs(root)
  current_rule = nil
  root.children.map! do |child|
    unless child.is_a?(Tree::RuleNode)
      nest_seqs(child) if child.is_a?(Tree::DirectiveNode)
      next child
    end
    seq = first_seq(child)
    seq.members.reject! {|sseq| sseq == "\n"}
    first, rest = seq.members.first, seq.members[1..-1]
    if current_rule.nil? || first_sseq(current_rule) != first
      current_rule = Tree::RuleNode.new([])
      current_rule.parsed_rules = make_seq(first)
    end
    if rest.empty?
      current_rule.children += child.children
    else
      child.parsed_rules = make_seq(*rest)
      current_rule << child
    end
    current_rule
  end
  root.children.compact!
  root.children.uniq!
  root.children.each {|v| nest_seqs(v)}
end