伪类

2017-09-26 本文已影响0人阿鲁提尔

1.div:first-child
2.div :first-child
3.div:first-of-type
4.div :first-of-type

用css添加序号

p{
  counter-increment:counter;
}
p:before{
  content"counter(counter)
}

  <p data-num="3">xxx</p>
  p{
    counter-increment;
  }
  p：before{
    content：attr(data-num)
  }