题目在这
http://www.chinesefeng.com/default.asp?tag=%E6%8B%9B%E8%81%98%E8%AF%95%E9%A2%98
二个的实现
Code<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<style type="text/css">
#x1
{
width:150px;
background-color:red;
height:50px;
left:50%;
top:50%;
position:absolute;
margin-top:-25px;
margin-left:-75px;}
#x2
{
width:50px;
height:150px;
background-color:red;
left:50%;
top:50%;
position:absolute;
margin-left:-25px;
margin-top:-75;}
</style>
</HEAD>
<BODY>
<div id="x1"></div>
<div id="x2"></div>
</BODY>
</HTML>
三个的实现
Code<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<style type="text/css">
<!--
/*这三个css有很多雷同的样式,怎么样重构哪*/
#x{width:50px;height:150px;position:absolute;left:50%;top:50%;margin-left:-25px;margin-top:-75px;background-color:red;}
#y{width:50px;height:50px;position:absolute;left:50%;top:50%;margin-left:-75px;margin-top:-25px;background-color:red;}
#z{width:50px;height:50px;position:absolute;left:50%;top:50%;margin-left:25px;margin-top:-25px;background-color:red;}
-->
</style>
</HEAD>
<BODY>
<div id="x"></div><div id="y"></div><div id="z"></div>
</BODY>
</HTML>
Code<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<TITLE> New Document </TITLE>
<META NAME="Generator" CONTENT="EditPlus">
<META NAME="Author" CONTENT="">
<META NAME="Keywords" CONTENT="">
<META NAME="Description" CONTENT="">
<style type="text/css">
<!--
/*这三个css有很多雷同的样式,这样重构哪*/
div {width:50px;position:absolute;left:50%;top:50%;background-color:red;}
#x{height:150px;margin-left:-25px;margin-top:-75px;}
#y{height:50px;margin-left:-75px;margin-top:-25px;}
#z{height:50px;margin-left:25px;margin-top:-25px;}
-->
</style>
</HEAD>
<BODY>
<div id="x"></div><div id="y"></div><div id="z"></div>
</BODY>
</HTML>