Horizontal 2 niveles!!!

<ul id="nav">
    <li><a href="https://www.script-tutorials.com/">Home</a></li>
    <li><a class="hsubs" href="#">Menu 1</a>
        <ul class="subs">
            <li><a href="#">Submenu 1</a></li>
            <li><a href="#">Submenu 2</a></li>
            <li><a href="#">Submenu 3</a></li>
            <li><a href="#">Submenu 4</a></li>
            <li><a href="#">Submenu 5</a></li>
        </ul>
    </li>
    <li><a class="hsubs" href="#">Menu 2</a>
        <ul class="subs">
            <li><a href="#">Submenu 2-1</a></li>
            <li><a href="#">Submenu 2-2</a></li>
            <li><a href="#">Submenu 2-3</a></li>
            <li><a href="#">Submenu 2-4</a></li>
            <li><a href="#">Submenu 2-5</a></li>
            <li><a href="#">Submenu 2-6</a></li>
            <li><a href="#">Submenu 2-7</a></li>
            <li><a href="#">Submenu 2-8</a></li>
        </ul>
    </li>
    <li><a class="hsubs" href="#">Menu 3</a>
        <ul class="subs">
            <li><a href="#">Submenu 3-1</a></li>
            <li><a href="#">Submenu 3-2</a></li>
            <li><a href="#">Submenu 3-3</a></li>
            <li><a href="#">Submenu 3-4</a></li>
            <li><a href="#">Submenu 3-5</a></li>
        </ul>
    </li>
    <li><a href="#">Menu 4</a></li>
    <li><a href="#">Menu 5</a></li>
    <li><a href="#">Menu 6</a></li>
    <li><a href="https://www.script-tutorials.com/flying-css3-navigation-menu/">Back</a></li>
</ul>

CSS

#nav,#nav ul {
    list-style: none outside none;
    margin: 0;
    padding: 0;
}
#nav {
    font-family: "Lucida Sans Unicode",Verdana,Arial,sans-serif;
    font-size: 13px;
    height: 36px;
    list-style: none outside none;
    margin: 40px auto;
    text-shadow: 0 -1px 3px #202020;
    width: 980px;

    /* border radius */
    -moz-border-radius:4px;
    -webkit-border-radius:4px;
    border-radius:4px;

    /* box shadow */
    -moz-box-shadow: 0px 3px 3px #cecece;
    -webkit-box-shadow: 0px 3px 3px #cecece;
    box-shadow: 0 3px 4px #8b8b8b;

    /* gradient */
    background-image: -webkit-gradient(linear, left bottom, left top, color-stop(0, #787878), color-stop(0.5, #5E5E5E), color-stop(0.51, #707070), color-stop(1, #838383));
    background-image: -moz-linear-gradient(center bottom, #787878 0%, #5E5E5E 50%, #707070 51%, #838383 100%);
    background-color:#5f5f5f;
}
#nav ul {
    left: -9999px;
    position: absolute;
    top: -9999px;
    z-index: 2;
}
#nav li {
    border-bottom: 1px solid #575757;
    border-left: 1px solid #929292;
    border-right: 1px solid #5d5d5d;
    border-top: 1px solid #797979;
    display: block;
    float: left;
    height: 34px;
    position: relative;
    width: 105px;
}
#nav li:first-child {
    border-left: 0 none;
    margin-left: 5px;
}
#nav li a {
    color: #FFFFFF;
    display: block;
    line-height: 34px;
    outline: medium none;
    text-align: center;
    text-decoration: none;

    /* gradient */
    background-image: -webkit-gradient(linear, left bottom, left top, color-stop(0, #787878), color-stop(0.5, #5E5E5E), color-stop(0.51, #707070), color-stop(1, #838383));
    background-image: -moz-linear-gradient(center bottom, #787878 0%, #5E5E5E 50%, #707070 51%, #838383 100%);
    background-color:#5f5f5f;
}

/* keyframes #animation1 */
@-webkit-keyframes animation1 {
    0% {
        -webkit-transform: scale(1);
    }
    30% {
        -webkit-transform: scale(1.3);
    }
    100% {
        -webkit-transform: scale(1);
    }
}
@-moz-keyframes animation1 {
    0% {
        -moz-transform: scale(1);
    }
    30% {
        -moz-transform: scale(1.3);
    }
    100% {
        -moz-transform: scale(1);
    }
}
#nav li > a:hover {
    /* css3 animation */
    -moz-animation-name: animation1;
    -moz-animation-duration: 0.7s;
    -moz-animation-timing-function: linear;
    -moz-animation-iteration-count: infinite;
    -moz-animation-direction: normal;
    -moz-animation-delay: 0;
    -moz-animation-play-state: running;
    -moz-animation-fill-mode: forwards;

    -webkit-animation-name: animation1;
    -webkit-animation-duration: 0.7s;
    -webkit-animation-timing-function: linear;
    -webkit-animation-iteration-count: infinite;
    -webkit-animation-direction: normal;
    -webkit-animation-delay: 0;
    -webkit-animation-play-state: running;
    -webkit-animation-fill-mode: forwards;
}
#nav li:hover > a {
    z-index: 4;
}
#nav li:hover ul.subs {
    left: 0;
    top: 34px;
    width: 150px;
}
#nav ul li {
    background: none repeat scroll 0 0 #838383;
    box-shadow: 5px 5px 5px rgba(0, 0, 0, 0.5);
    opacity: 0;
    width: 100%;

    /*-webkit-transition:all 0.3s ease-in-out;
    -moz-transition:all 0.3s ease-in-out;
    -o-transition:all 0.3s ease-in-out;
    -ms-transition:all 0.3s ease-in-out;
    transition:all 0.3s ease-in-out;*/
}

/* keyframes #animation2 */
@-webkit-keyframes animation2 {
    0% {
        margin-left:185px;
    }
    100% {
        margin-left:0px;
        opacity:1;
    }
}
@-moz-keyframes animation2 {
    0% {
        margin-left:185px;
    }
    100% {
        margin-left:0px;
        opacity:1;
    }
}
#nav li:hover ul li {
    /* css3 animation */
    -moz-animation-name: animation2;
    -moz-animation-duration: 0.3s;
    -moz-animation-timing-function: linear;
    -moz-animation-iteration-count: 1;
    -moz-animation-direction: normal;
    -moz-animation-delay: 0;
    -moz-animation-play-state: running;
    -moz-animation-fill-mode: forwards;

    -webkit-animation-name: animation2;
    -webkit-animation-duration: 0.3s;
    -webkit-animation-timing-function: linear;
    -webkit-animation-iteration-count: 1;
    -webkit-animation-direction: normal;
    -webkit-animation-delay: 0;
    -webkit-animation-play-state: running;
    -webkit-animation-fill-mode: forwards;

    /*-webkit-transition:all 0.3s ease-in-out;
    -moz-transition:all 0.3s ease-in-out;
    -o-transition:all 0.3s ease-in-out;
    -ms-transition:all 0.3s ease-in-out;
    transition:all 0.3s ease-in-out;*/
}
/* animation delays */
#nav li:hover ul li:nth-child(1) {
    -moz-animation-delay: 0;
    -webkit-animation-delay: 0;
}
#nav li:hover ul li:nth-child(2) {
    -moz-animation-delay: 0.05s;
    -webkit-animation-delay: 0.05s;
}
#nav li:hover ul li:nth-child(3) {
    -moz-animation-delay: 0.1s;
    -webkit-animation-delay: 0.1s;
}
#nav li:hover ul li:nth-child(4) {
    -moz-animation-delay: 0.15s;
    -webkit-animation-delay: 0.15s;
}
#nav li:hover ul li:nth-child(5) {
    -moz-animation-delay: 0.2s;
    -webkit-animation-delay: 0.2s;
}
#nav li:hover ul li:nth-child(6) {
    -moz-animation-delay: 0.25s;
    -webkit-animation-delay: 0.25s;
}
#nav li:hover ul li:nth-child(7) {
    -moz-animation-delay: 0.3s;
    -webkit-animation-delay: 0.3s;
}
#nav li:hover ul li:nth-child(8) {
    -moz-animation-delay: 0.35s;
    -webkit-animation-delay: 0.35s;
}