.menu {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}

.menu li {
    position: relative;
    margin-right: 5px;
}

.menu a {
    display: block;
    padding: 10px 20px;
    background-color: blue;
    color: white;
    text-decoration: none;
}

.menu a:hover {
    background-color: oldlace;
    color: black;
}

.submenu {
    list-style: none;
    padding: 0;
    margin: 0;
    position: absolute;
    top: 100%;
    left: 0;
    display: none;
}

.dropdown:hover .submenu {
    display: block;
}

.submenu a {
    width: 200px;
    background-color: blue;
}