nav {
background-color: #333;
height: 40px;
}
nav ul {
margin: 0;
padding: 0;
list-style-type: none;
}
nav li {
float: left;
position: relative;
}
nav a {
display: block;
color: #fff;
font-size: 16px;
line-height: 40px;
padding: 0 20px;
text-decoration: none;
}
nav li:hover {
background-color: #555;
}
nav li:hover >ul {
display: block;
}
nav ul ul {
position: absolute;
top: 40px;
left: 0;
display: none;
background-color: #555;
}
nav ul ul li {
float: none;
width: 200px;
}
nav ul ul a {
line-height: 30px;
padding: 0 20px;
}
nav ul ul ul {
top: 0;
left: 200px;
}