css弹出大图

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS Popup Image</title>
    <style>
        .thumbnail {
            width: 200px;
            height: 200px;
            overflow: hidden;
            position: relative;
        }
        .thumbnail img {
            width: 100%;
            height: auto;
            transition: transform 0.3s ease;
        }
        .thumbnail:hover img {
            transform: scale(2);
        }
    </style>
</head>
<body>
    <div class="thumbnail">
        <img src="small-image.jpg" alt="Small Image">
    </div>
</body>
</html>