网页雏形
代码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
.a{
width: 1000px;
height: 100px;
background-color: blue;
margin: 0 auto;
}
.b{
width: 1000px;
height: 700px;
background-color: yellow;
margin: 10px auto;
}
.b1{
width: 300px;
height: 600px;
background-color: red;
float: left;
margin: 50px 0;
margin-left: 25px;
}
.b2{
width: 300px;
height: 600px;
background-color: green;
float: left;
margin: 50px 25px;
}
.b3{
width: 300px;
height: 600px;
background-color: black;
float: left;
margin: 50px 0;
margin-right: 25px;
}
.c{
width: 1000px;
height: 100px;
background-color: black;
margin: 0 auto;
}
</style>
</head>
<body>
<div class="a"></div>
<div class="b">
<div class="b1"></div>
<div class="b2"></div>
<div class="b3"></div>
</div>
<div class="c"></div>
</body>
</html>
效果：
image.png
