css实现高度自适应

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Height Adaptive Example</title>
    <style>
        .container {
            display: flex;
            flex-direction: column;
            height: 100vh; /* 使容器高度占满整个视口高度 */
        }
        .header {
            background-color: #f1f1f1;
            padding: 20px;
        }
        .content {
            flex: 1; /* 使内容区域自适应高度 */
            background-color: #ddd;
            padding: 20px;
        }
        .footer {
            background-color: #f1f1f1;
            padding: 20px;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="header">Header</div>
        <div class="content">Content</div>
        <div class="footer">Footer</div>
    </div>
</body>
</html>