body{
  font-family: Arial, Helvetica, sans-serif;
}

div {
  float: left;
}

ul {
  list-style-type: none;
  margin: 1px;
  padding: 0;
  overflow: hidden;
}

li {
  float: left;
  margin-right: 1px;
  background-color: #AAA;
}

li a {
  display: block;
  color: white;
  text-align: center;
  padding: 4px;
  text-decoration: none;
}

li a:hover {
  background-color: #CCC;
}