CSS一列的自适应：
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Strict//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<style type="text/css">
div{
background-color: #FFFF00;
border: 2px solid #000000;
text-align: center;
padding-top: 40px;
font-family: "宋体";
font-size: 14px;
}
#layout{
height: 300px;
width:40%;
margin: auto; //这样就能在自适应的同时左右居中
}
</style>
</head>
<body>
<div id="layout">一列固定宽度布局</div><!-- 相同属性的，后者会把前者覆盖 -->
</body>
</html>
