<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
div.ui_infor p{font-size:50px; color:red;}
.ui_infor p{ font-size::12px; color:green;}
</style>
</head>
<body>
<div class="ui_infor">
<p>test of css</p>
</div>
</body>
</html>
显示结果为50px 红色字体
注： div.ui_infor 中间没有空格