页面后台导航制作 -

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body {
            height: 100vh;
            width: 100vw;
            display: grid;
            grid-template-columns: 10em 1fr;
            grid-template-rows: 6em 1fr;
            margin: 0;
        }
        body .header {
            grid-column-end: span 2;
            border-bottom: 1px solid currentColor;
            background-color: rgb(25, 179, 214);
            padding: 2em;
            display: flex;
            align-items: center;
        }
        body .header div {
            margin-left: auto;
        }
        body .nav {
            background-color: rgb(243, 232, 16);
            margin: 0;
            padding-top: 1em;
            list-style: none;
        }
        body iframe {
            width: calc(100vw - 10em);
            height: calc(100vh - 6em);
            border-left: 1px solid currentColor;
        }
    </style>
</head>
<body>
    <div class="header">
        <h1>管理后台</h1>
        <div>
            <span>administrator</span>
            <a href="">退出</a>
        </div>
    </div>
    <ul class="nav">
        <li><a href="demo1.html" target="content">链接1</a></li>
        <li><a href="demo2.html" target="content">链接2</a></li>
        <li><a href="demo3.html" target="content">链接3</a></li>
        <li><a href="demo4.html" target="content">链接4</a></li>
        <li><a href="demo5.html" target="content"></a></li>
        <li><a href="demo6.html" target="content"></a></li>
    </ul>
    <iframe src="" frameborder="2" name="content"></iframe>
</html>