左右浮动三列布局

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>

        .left{float: left;200px;height:500px;background-color:red}
        .right{float: right;200px;height:500px;background-color:red}
        .middle{height:500px;margin:0 210px;background-color:#000}
    </style>
</head>
<body>
<div class="main">
    <div class="left"></div>
    <div class="right"></div>
    <div class="middle">111222</div>
</div>

</body>
</html>

左右浮动 三列布局

左右浮动三列布局