div css垂直下拉三级菜单

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Vertical Dropdown Menu</title>
    <style>
        body {
            font-family: Arial, sans-serif;
        }
        .menu {
            width: 200px;
        }
        .menu ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        .menu li {
            position: relative;
        }
        .menu li a {
            display: block;
            padding: 10px;
            background-color: #f1f1f1;
            text-decoration: none;
            color: #333;
        }
        .menu li a:hover {
            background-color: #ddd;
        }
        .sub-menu {
            display: none;
            position: absolute;
            left: 100%;
            top: 0;
            width: 200px;
        }
        .menu li:hover > .sub-menu {
            display: block;
        }
        .sub-menu .sub-sub-menu {
            display: none;
            position: absolute;
            left: 100%;
            top: 0;
            width: 200px;
        }
        .sub-menu li:hover > .sub-sub-menu {
            display: block;
        }
    </style>
</head>
<body>
    <div class="menu">
        <ul>
            <li><a href="#">Menu 1</a>
                <ul class="sub-menu">
                    <li><a href="#">Sub Menu 1.1</a>
                        <ul class="sub-sub-menu">
                            <li><a href="#">Sub Sub Menu 1.1.1</a></li>
                            <li><a href="#">Sub Sub Menu 1.1.2</a></li>
                        </ul>
                    </li>
                    <li><a href="#">Sub Menu 1.2</a></li>
                </ul>
            </li>
            <li><a href="#">Menu 2</a></li>
        </ul>
    </div>
</body>
</html>