浮动和margin负值三列布局

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .left{position:relative;float:left;200px;height:500px;background-color:red}
        .middle{float:left;100%;margin:0 -200px;height:500px;background-color:#c8dcf2;padding:0 200px;box-sizing: border-box}
        .right{float:left;200px;height:500px;background-color:red}
    </style>
</head>
<body>
<div class="main">
    <div class="left"></div>
    <div class="middle"></div>
    <div class="right"></div>
</div>

</body>
</html>

浮动和margin负值 三列布局

浮动和margin负值三列布局