Membuat Menu Dropdown CSS3 Transision

Saya akan share cara membuat dropdown animasi menggunakan css3 tanpa javascript

Code untuk Html :

<header>
<div id="top">
  <nav id="topmenu">
    <ul>
     <li><a href="">Home</a></li>
     <li><a href="">About</a></li>
     <li><a href="">Portfolio<span class="arrow">More Link</span></a>
        <ul class="sublist">
           <li><a href="#">Sub link</a></li>
           <li><a href="#">Sub link</a></li>
           <li><a href="#">Sub link<span class="arrow-right">More Link</span></a>
        <ul class="subsublist">
            <li><a href="#">Sub Sub link</a></li>
            <li><a href="#">Sub Sub link</a></li>
            <li><a href="#">Sub Sub link</a></li>
       </ul>
    </li>
    </ul>
    </li>
    <!-- OTHER LINKS SECTION -->
    </ul>
</nav>
</div>
</header>

Untuk CSS silahkan masukan kode berikut:

/* LINK TRANSITION */
a {
-moz-transition:color 0.3s ease-out;
-webkit-transition:color 0.3s ease-out;
-o-transition:color 0.3s ease-out;
transition:color 0.3s ease-out;
}
/* MENU STYLE */
header {
width:100%;
}
header #top {
background:#222;
float:left;
height:30px;
line-height:30px;
width:100%;
}
header nav#topmenu {
margin:0 auto;
padding:0 15px;
position:relative;
width:960px;
}
header nav#topmenu ul {
margin:0
padding:0;
}
header nav#topmenu ul li {
float:left;
position:relative;
font-size:10px;
list-style:none;
margin:0;
padding:0;
width:90px;
text-align:center;
text-transform:uppercase;
border-right:1px solid #ccc; }
header nav#topmenu ul li:first-child {
border-left:1px solid #ccc;
}
header nav#topmenu ul li a {
color:rgba(255,255,255,0.6);
text-decoration:none;
display:block;
}
header nav#topmenu ul li a:hover {
color:#fff;
}
header nav#topmenu ul li:hover > a { /* ACTIVATE LINK WHEN THE MOUSE OVER SUB-MENU */
color:#fff;
}
header nav#topmenu ul li span {
background:url(arrow.png) center no-repeat;
height:10px;
position:absolute;
text-indent:-9999px;
top:10px;
right:5px;
width:10px;
}
header nav#topmenu ul li span.arrow {
background-position:0 2px;
}
header nav#topmenu ul li span.arrow-right {
background-position:-10px 2px;
}
header nav#topmenu ul li ul.sublist { /* FIRST SUB-MENU STYLE */
float:left;
list-style:none;
margin:0;
padding:0;
position:absolute;
left:0px;
top:31px;
background:#222;
width:90px;
opacity:0;
visibility:hidden; /* Avoids being selected even if the opacity is set to 0 */
     
        /* CSS3 Multiple Transitions */
-moz-transition:opacity 0.2s 0.1s ease-out, visibility 0.1s 0.1s linear;
-webkit-transition:opacity 0.3s ease-out, visibility 0.1s 0.1s linear;
-o-transition:opacity 0.3s ease-out, visibility 0.1s 0.1s linear;
transition:opacity 0.3s ease-out, visibility 0.1s 0.1s linear;
}
header nav#topmenu ul li ul.sublist li {
border:none;
border-bottom:1px solid #ccc;
clear:both;
margin-top:-15px;
padding:0;
width:90px;
-moz-transition:opacity 0.1s 0.15s ease-out, margin 0.3s 0.1s ease-out;
-webkit-transition:opacity 0.1s 0.15s ease-out, margin 0.3s 0.1s ease-out;
-o-transition:opacity 0.15s 0.15s ease-out, margin 0.3s 0.1s ease-out;
transition:opacity 0.15s 0.15s ease-out, margin 0.3s 0.1s ease-out;
}
header nav#topmenu ul li ul.sublist li a {
color:rgba(255,255,255,0);
}
header nav#topmenu ul li:hover ul.sublist {
opacity:1;
visibility:visible;
}
header nav#topmenu ul li:hover ul.sublist li {
margin-top:0;
opacity:1;
}
header nav#topmenu ul li:hover ul.sublist li a {
color:rgba(255,255,255,0.6); -moz-transition:color 0.1s ease-out;
-webkit-transition:color 0.1s ease-out;
-o-transition:color 0.1s ease-out;
transition:color 0.1s ease-out;
}
header nav#topmenu ul li:hover ul.sublist li a:hover {
color:rgba(255,255,255,1); -moz-transition:color 0.3s ease-out;
-webkit-transition:color 0.3s ease-out;
-o-transition:color 0.3s ease-out;
transition:color 0.3s ease-out;
}
header nav#topmenu ul li:hover ul.sublist li:hover > a {
        /* ACTIVATE LINK SUB-MENU WHEN THE MOUSE OVER SUBSUB-MENU */
color:#fff;
}
/* SUB-MENU SUB STYLE */
header nav#topmenu ul li ul.sublist li ul.subsublist {
float:left;
list-style:none;
margin:0;
padding:0;
position:absolute;
left:61px;
top:0px;
background:#222;
width:90px;
opacity:0;
visibility:hidden;
-moz-transition:opacity 0.2s 0.01s ease-in-out, left 0.2s 0.1s ease-out, visibility 0.1s 0.1s linear;
-webkit-transition:opacity 0.2s 0.01s ease-in-out, left 0.2s 0.1s ease-out, visibility 0.1s 0.1s linear;
-o-transition:opacity 0.2s 0.01s ease-in-out, left 0.2s 0.1s ease-out, visibility 0.1s 0.1s linear;
transition:opacity 0.2s 0.01s ease-in-out, left 0.2s 0.1s ease-out, visibility 0.1s 0.1s linear;
}
header nav#topmenu ul li ul.sublist li ul.subsublist li{
border:none;
border-bottom:1px solid #ccc;
clear:both;
margin:0;
padding:0;
width:90px;
opacity:1;
}
header nav#topmenu ul li ul.sublist li:hover ul.subsublist {
opacity:1;
left:91px;
visibility:visible;
}