jquery 动画切换

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>jQuery 动画示例</title>
    <script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
    <style>
        #box {
            width: 100px;
            height: 100px;
            background-color: red;
            margin: 20px;
        }
    </style>
</head>
<body>
    <div id="box"></div>
    <button id="animateBtn">开始动画</button>

    <script>
        $(document).ready(function() {
            $('#animateBtn').click(function() {
                $('#box').animate({
                    width: '200px',
                    height: '200px',
                    opacity: 0.5
                }, 1000, function() {
                    // 动画完成后执行的回调函数
                    alert('动画完成');
                });
            });
        });
    </script>
</body>
</html>