/* Menu chính */
#menu {
    list-style: none;
    padding: 0;
    margin: 0;
    width: 150px;
}

#menu li {
    position: relative;
}

#menu a {
    display: block;
    padding: 10px;
    background-color: #000000;
    color: #FFF;
    text-decoration: none;
    border-bottom: 1px solid #FFF;
}

/* Hover */
#menu a:hover {
    background-color: darkgray;
}

/* Menu cấp 2 */
.submenu {
    position: absolute;
    top: 0;
    left: 150px;
    display: none;
    width: max-content;
}

/* Menu cấp 3 */
.submenu2 {
    position: absolute;
    top: 0;
    left: 150px;
    display: none;
    width: max-content;
}

.submenu3 {
    position: absolute;
    top: 0;
    left: 150px;
    display: none;
    width: max-content;
}

/* Hiện menu khi hover */
.has-sub:hover > .submenu {
    display: block;
}

.has-sub:hover > .submenu2 {
    display: block;
}

.has-sub:hover > .submenu3 {
    display: block;
}