HTML代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>对其</title>
<link rel="stylesheet" type="text/css" href="Align.css">
</head>
<body>
<div class="m1"></div>
<div class="m2"></div>
<div class="m3"></div>
</body>
</html>CSS代码
*{
margin: 0px;
}
/*这里的*也是通配符的意思，将默认的外边距全部去掉*/
.m1{
width: 75%;
height: 100px;
background: cornflowerblue;
margin: 50px auto;
}
/*margin-left和right分别控制左右边距，margin第一个属性代表上下，后面代表左右*/
.m2{
width: 75%;
height: 75px;
background-color: deepskyblue;
position: absolute;
left: 0px;
}
.m3{
width: 75%;
height: 100px;
background-color:firebrick;
float: right;
}效果：
