css :three column +top box
<!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;
color:#ccc;
background-color:#333;
}
#top{
margin:20px 20px 0px 20px;
padding:10px;
background: #666;
border:5px solid #ccc;
height:70px;
}
#left{
margin:20px;
padding:10px;
width:120px;
border:5px solid white;
position:absolute;
top:120px; /*top垂直高度为120px*/
left:0px;
background:#666;
}
#middle{
margin:20px 190px;/*left宽度为190px*/
padding:10px;
background:#666;
border:5px solid white;
}
#right{
position:absolute;
top:120px;
right:0px;
margin:20px;
padding:10px;
border:5px solid #ccc;
background:#666;
width:120px;
}
</style>
</head>
<body>
<div >
<p>1</p>
</div>
<div >
<p>1</p>
</div>
<div >
<pre>
#top {
margin: 20px 20px 0px 20px;
padding: 10px;
border: 5px solid #ccc;
background: #666;
height: 100px; /* ie5win fudge begins */
voice-family: "\"}\"";
voice-family:inherit;
height: 70px;
}
html>body #top {
height: 70px; /* ie5win fudge ends */
}
#left {
position: absolute;
top: 120px;
left: 0px;
margin: 20px;
padding: 10px;
border: 5px solid #ccc;
background: #666;
width: 150px; /* ie5win fudge begins */
voice-family: "\"}\"";
voice-family:inherit;
width: 120px;
}
html>body #left {
width: 120px; /* ie5win fudge ends */
}
#middle {
margin: 20px 190px 20px 190px;
padding: 10px;
border: 5px solid #ccc;
background: #666;
}
#right {
position: absolute;
top: 120px;
right: 0px; /* Opera5.02 will show a space
at right when there is no scroll bar */
margin: 20px;
padding: 10px;
border: 5px solid #ccc;
background: #666;
width: 150px; /* ie5win fudge begins */
voice-family: "\"}\"";
voice-family:inherit;
width: 120px;
}
html>body #right {
width: 120px; /* ie5win fudge ends */
}
</pre>
<div align="right"><p><a href="css/03_3columnplustopbox.css">[full css]</a></p></div>
</div>
<div >
<p>1</p>
</div>
</body>
</html>left：Sets the left margin edge for a positioned box。
Definition and Usage
For absolutely positioned elements, the left property sets the left edge of an element to a unit to the left/right of the left edge of its containing element.
For relatively positioned elements, the left property sets the left edge of an element to a unit to the left/right to its normal position.
http://www.w3schools.com/cssref/pr_pos_left.asp
显示如下：
http://www.thenoodleincident.com/tutorials/box_lesson/basic4.html