.main-menu li.dropdown {
    position: relative;
}

.main-menu li .submenu {
    display: none;
    position: absolute;
    background-color: white;
    min-width: 200px;
    z-index: 99;
    top: 100%;
    left: 0;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.main-menu li:hover .submenu {
    display: block;
}

.main-menu .submenu li {
    padding: 8px 16px;
}

.main-menu .submenu li a {
    display: block;
    color: #333;
}