<!DOCTYPE html>
<html lang="en">
<head>
???<meta charset="UTF-8">
???<title>Title</title>
???<link rel="stylesheet" href="aa.css">
???<style>
???????.c1{
???????????background-color:pink;
???????????height: 100px;
???????????width:100px;
???????}
???</style>
???<link rel="stylesheet" href="bb.css">
</head>
<body>
???<!--从标签为基准 由下到上依次查找-->
???<div class="c1" style="background-color: green; height: 100px ; width: 100px;"></div>
</body>
</html>
css2
原文地址：https://www.cnblogs.com/jiadan/p/9215913.html