.menu,
.menu ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.menu {
    margin: 30px;
}

.menu > li {
    display: inline-block;
    position: relative;
    margin-right: 1px;
}

.menu li a {
    display: block;
    padding: 10px 15px;
    background: blue;
    color: white;
    text-decoration: none;
    white-space: nowrap;
}

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

.menu li ul {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: max-content;
    z-index: 1000;
}

.menu li:hover > ul {
    display: block;
}

.menu li ul li {
    position: relative;
}

.menu li ul li ul {
    top: 0;
    left: 100%;
}