header-content-footer 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style type="text/css">
        .box {
            width: 500px;
            height: 500px;
            display: flex;
            flex-direction: column;
        }
        .header {
            width: 100%;
            height: 100px;
            background-color: red;
        }
        .content {
            width: 100%;
            flex: 1;
            background-color: yellow;
        }
        .footer {
            width: 100%;
            height: 40px;
            background-color: blue;
        }
    </style>
</head>
<body>
<div class="box">
    <div class="header"></div>
    <div class="content"></div>
    <div class="footer"></div>
</div>
</body>
</html>
posted @ 2020-11-09 16:22  Zeronera  阅读(265)  评论(0)    收藏  举报