#menu {
  width:820px;
  padding:0;
  margin:0;
  list-style-type: none;
}
#menu li {
  width:20%;
  float:left;
  padding:0;
  margin:0;
  text-align:center;
}
#menu li a {
  width:auto;
  color:#fff;
  font-size:20px;
  font-weight:bold;
  padding:15px 0;
  text-decoration:none;
  display:block;
  background:#000000;
}
#menu li a:hover {
  background:#FF0000;
}