css下拉菜单箭头旋转动画效果

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS Dropdown Arrow Animation</title>
    <style>
        .dropdown {
            position: relative;
            display: inline-block;
        }

        .dropdown-content {
            display: none;
            position: absolute;
            background-color: #f9f9f9;
            min-width: 160px;
            box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
            z-index: 1;
        }

        .dropdown:hover .dropdown-content {
            display: block;
        }

        .dropdown-btn {
            background-color: #4CAF50;
            color: white;
            padding: 16px;
            font-size: 16px;
            border: none;
            cursor: pointer;
        }

        .dropdown-btn::after {
            content: '▼';
            margin-left: 5px;
            transition: transform 0.3s ease;
        }

        .dropdown:hover .dropdown-btn::after {
            transform: rotate(180deg);
        }
    </style>
</head>
<body>
    <div class="dropdown">
        <button class="dropdown-btn">Dropdown</button>
        <div class="dropdown-content">
            <a href="#">Link 1</a>
            <a href="#">Link 2</a>
            <a href="#">Link 3</a>
        </div>
    </div>
</body>
</html>