【sidebar】
<!DOCTYPE html>
<html>
<head>
<style type='text/css'>
#container {
width: 100%;
}
#sidebar, #content {
height: 200px;
}
#sidebar {
background: yellow;
width: 200px;
float: left;
}
#content {
background: orange;
}
</style>
</head>
<body>
<div id="container">
<div id="content">
content
<div id="sidebar">sidebar</div>
</div>
</div>
</body>
</html>
