基本 #id element .class * selector1,selector2,selectorN 层级 ancestor descendant parent > child prev + next prev ~ siblings 基本筛选器 :first :not(selector) :even :odd :eq(index) :gt(index) :lang1.9+ :last :lt(index) :header :animated :focus :root1.9+ :target1.9+ 内容 :contains(text) :empty :has(selector) :par