Horizontales Drop-Down-Menü

/* horizontal_menu */


.menu{
    border:none;
    border:0px;
    margin:0px;
    padding:0px;
     font: 67.5% "Lucida Sans Unicode", "Bitstream Vera Sans", "Trebuchet  Unicode MS", "Lucida Grande", Verdana, Helvetica, sans-serif;
    font-size:11px;
    font-weight:bold;
    }
.menu ul{
    background:#333333;
    height:30px;
    list-style:none;
    margin:0;
    padding:0;
    }
    .menu li{
        float:left;
        padding:0px;
        }
    .menu li a{
        background:#333333 url("images/seperator.gif") bottom right no-repeat;
        color:#cccccc;
        display:block;
        font-weight:normal;
        line-height:30px;
        margin:0px;
        padding:0px 5px;
        text-align:center;
        text-decoration:none;
        }
        .menu li a:hover, .menu ul li:hover a{
            background: #2580a2 url("images/hover.gif") bottom center no-repeat;
            color:#FFFFFF;
            text-decoration:none;
            }
    .menu li ul{
        background:#333333;
        display:none;
        height:auto;
        padding:0px;
        margin:0px;
        border:0px;
        position:absolute;
        width:225px;
        z-index:200;
        /*top:1em;
        /*left:0;*/
        }
    .menu li:hover ul{
        display:block;


        }
    .menu li li {
        background:url('images/sub_sep.gif') bottom left no-repeat;
        display:block;
        float:none;
        margin:0px;
        padding:0px;
        width:225px;
        }
    .menu li:hover li a{
        background:none;


        }
    .menu li ul a{
        display:block;
        height:12px;
        font-size:11px;
        font-style:normal;
        margin:0px;
        padding:0px 10px 15px 15px;
        text-align:left;
        }
        .menu li ul a:hover, .menu li ul li:hover a{
            background:#2580a2 url('images/hover_sub.gif') center left no-repeat;
            border:0px;
            color:#ffffff;
            text-decoration:none;
            }
    .menu p{
        clear:left;
        }

<div class="menu">
        <ul>
            <li><a href="#">Thema 1</a></li>
            <li><a href="#">Thema 2</a>
                <ul>
                <li><a href="#">Thema 2.1</a></li>
                <li><a href="#">Thema 2.2</a></li>
                <li><a href="#">Thema 2.3</a></li>
                </ul>
          </li>
            <li><a href="#">Thema 3</a>
                <ul>
                <li><a href="#">Thema 3.1</a></li>
                <li><a href="#">Thema 3.2</a></li>
                <li><a href="#">Thema 3.3</a></li>
                </ul>
          </li>
        </ul>
    </div>