为 clearfix 类所在的 div 内部最后处添加一个 div 标签，内容为 . ，高度为0， 隐藏
<!DOCTYPE html><html lang="en"><head> ???<meta charset="UTF-8"> ???<title>Title</title> ???<style> ???????.left{ ???????????float: left; ???????} ???????.container{ ???????????background-color: red; ???????} ???????.container .item{ ???????????width: 180px; ???????????height: 150px; ???????????background-color: #303a40; ???????????border: 1px solid red; ???????} ???????.clearfix:after{ ???????????content: '.'; ???????????display: block; ???????????clear: both; ???????????visibility: hidden; ???????????height: 0; ???????} ???</style></head><body> ???<div class="container clearfix"> ???????<div class="item left"></div> ???????<div class="item left"></div> ???????<div class="item left"></div> ???????<div class="item left"></div> ???????<div class="item left"></div> ???????<div class="item left"></div> ???????<div class="item left"></div> ???????<div class="item left"></div> ???</div> ???<div>abcd</div></body></html>HTML 练习清除浮动 :after
原文地址：https://www.cnblogs.com/klvchen/p/10522008.html