ul#menu {
list-style-type: none;
width: 100%; /* pr�cision pour Opera */
}

ul#menu li {
float: left;
}

ul#menu a {
float: left;
margin: 0 2px;
padding: 5px 15px;
text-align: center;
border: 1px solid gray;
text-decoration: none;
color: #000;
background: #fff;
}

ul#menu a:hover {
background: #ccc;
border: 1px solid gray; 
}