【header】
<!DOCTYPE html>
<html>
<head>
<style type='text/css'>
.wrapper {
display: table;
}
.header, .footer {
width: 100%;
background: #999;
height: 200px;
}
.content {
width: 2500px;
height: 100px;
background: #9B191B;
}
</style>
</head>
<body>
<div class="wrapper">
<div class="header">this is header</div>
<div class="content">this is content</div>
<div class="footer">this is footer</div>
</div>
</body>
</html>
