.menu-item{
    float: left;
}

nav ul{
    list-style: none;
}

nav a{
    text-decoration: none;
    padding: 10px;
    display: block;
}

nav ul, nav li{
    padding: 0px;
    margin: 0px;
}

nav li{
    width: 100px;
    background-color: lightgray;
}

nav{
    background-color: lightgray;
    overflow: auto;
}

.submenu{
    display: none;
    position: absolute;
}

.menu-item:hover .submenu{
    display: block;
}

nav li:hover{
    background-color: yellow;
}