css设定div固定比例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Fixed Ratio Div</title>
    <style>
        .container {
            position: relative;
            width: 100%;
            padding-bottom: 56.25%; /* 16:9 aspect ratio */
            background-color: #f0f0f0;
        }
        .content {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: #000;
        }
    </style>
</head>
<body>
    <div class="container">
        <div class="content">
            <!-- 内容 -->
        </div>
    </div>
</body>
</html>