(1)浮动(float)
float:
参数:
none:默认 无浮动
left:左浮动
right:右浮动
(2)清除浮动(clear)
clear:
参数
none:无效果
left:清除右浮动
right:清除右浮动
both:扩充父元素
2.定位(position)
参数:
static:静态定位
relative:相对定位
是以元素作为基准设置偏移量
absolute:绝对定位
默认以浏览器为基准
设定之后其他浮动元素以这个元素浮动
fixed:固定定位
以浏览器窗口
3.z-index
z-index属性;调整重叠元素的上下位置,值大的位于值小的元素上方,默认是0,可以为正也可以为负,元素相同则保持原样上下覆盖关系
4.display
display属性:
参数:none:默认
inline:行级元素
block:块级元素
例1 工字型排版
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS排版</title>
<style>
*{
margin: 0;
padding: 0;
}
header{
padding-top: 25px;
background-color: chartreuse;
text-align: center;
width: 100%;
height:50px;
}
.midder{
width: 1200px;
height: 1000px;
background-color: coral;
text-align: center;
margin-left: 350px;
}
nav{
width: 100%;
height: 50px;
background-color:cyan;
padding-top: 25px;
}
footer{
width: 100%;
height: 200px;
padding-top: 100px;
text-align: center;
background-color: darkgray;
}
.content{
width: 100%;
height: 950px;
text-align: center;
padding-top: 525px;
}
</style>
</head>
<body>
<header>顶部</header>
<div class="midder">
<nav>导航</nav>
<div class="content">内容</div>
</div>
<footer>页脚</footer>
</body>
</html>
例2 工字型排版(浮动)
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS排版</title>
<style>
*{
margin: 0;
padding: 0;
}
header{
padding-top: 25px;
background-color: chartreuse;
text-align: center;
width: 100%;
height:50px;
}
.midder{
width: 1200px;
height: 900px;
background-color: coral;
text-align: center;
margin-left: 350px;
}
nav{
width: 1200px;
margin-left: 350px;
height: 50px;
text-align: center;
background-color:cyan;
padding-top: 25px;
}
footer{
width: 100%;
height: 200px;
padding-top: 100px;
text-align: center;
background-color: darkgray;
}
.midder .left{
float:left;
width: 400px;
height:300px;
background-color: darkred;
padding-top: 300px;
text-align: center;
}
.midder .right{
width: 800px;
float: right;
}
.midder .right .shang{
background-color:darkslateblue;
width: 100%;
height: 300px;
}
.midder .right .xia{
background-color:darkslategrey;
width: 100%;
height: 300px;
}
.ad{
width: 1200px;
height: 150px;
margin-left: 350px;
position: relative;
}
.ad .ad_left{
width: 400px;
height: 150px;
background-color: deepskyblue;
}
.ad .ad_right{
width: 400px;
height: 150px;
background-color: brown;
position:absolute;
top: 0px;
right: 0px;
}
.ad .ad_center{
background-color: burlywood;
position:absolute;
top: 0px;
left: 400px;
width: 400px;
height: 150px;
}
.clear{
clear: both;
}
</style>
</head>
<body>
<header>顶部</header>
<nav>导航</nav>
<div class="midder">
<div class="left">left</div>
<div class="right">
<div class="shang">right-上</div>
<div class="xia">right-下</div>
</div>
<div class=".clear"></div>
</div>
<div class="ad">
<div class="ad_left">ad_left</div>
<div class="ad_center">ad_center</div>
<div class="ad_right">ad_right</div>
</div>
<footer>页脚</footer>
</body>
</html>