字体没有发生变化
<!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">
.body{margin:0;padding:0;font-size:50px;color:#FFF}
.top{height:100px;background:#666
}
.main{
height:800px;background:#F00
}
.main_left{width:200px;height:800px;background:#009;float:left}
.main_right{margin-left:210px;height:800px;background:#0F9}
.bottom{height:100px;background:#F9C;clear:both}
</style>
</head>
<body>
<div class="top">top</div>
<div class="main">
<div class="main_left">left</div>
<div class="main_right">right</div>
</div>
<div class="bottom">bottom</div>
</body>
</html>
如上代码，字体大小颜色没有变化，怎么回事
