如何让我的水平 subnav 居中对齐？

Question

我在这里有一个带有水平子菜单的水平导航栏。我的问题是；如何让 mysubnav 中的元素居中而不是一直向左推？

请看这个 jsfiddle 来说明我的意思。

感谢大家抽出宝贵的时间！我愿意接受所有建议，无论是 CSS 还是 JavaScript。

http://jsfiddle.net/gbkdd7gg/2/

HTML

<div id="menu">
    <ul id="navbar">
        <li><a href="#">Occasions</a>

            <ul>
                <li><a href="#">Valentine's Day</a>
                </li>
                <li><a href="#">Easter</a>
                </li>
                <li><a href="#">Mother's Day</a>
                </li>
                <li><a href="#">Father's Day</a>
                </li>
                <li><a href="#">Wedding</a>
                </li>
                <li><a href="#">Birthday</a>
                </li>
                <li><a href="#">Baby</a>
                </li>
            </ul>
        </li>
        <li><a href="#">Cards &amp; Invitations</a>

            <ul>
                <li><a href="#">Invitations</a>
                </li>
                <li><a href="#">Baby</a>
                </li>
                <li><a href="#">Weddings</a>
                </li>
                <li><a href="#">Announcements</a>
                </li>
                <li><a href="#">Holiday</a>
                </li>
            </ul>
        </li>
        <li><a href="#">Canvas Prints</a>

            <ul>
                <li><a href="#">Full Wrap</a>
                </li>
                <li><a href="#">Colour Edge Wrap</a>
                </li>
                <li><a href="#">Frame</a>
                </li>
            </ul>
        </li>
        <li><a href="#">Mugs</a>

            <ul>
                <li><a href="#">11oz Single Image Mug</a>
                </li>
                <li><a href="#">11oz Double Image Mug</a>
                </li>
                <li><a href="#">11oz Scrapbook Mug</a>
                </li>
                <li><a href="#">11oz Fullwrap Mug</a>
                </li>
                <li><a href="#">14oz Travel Mug</a>
                </li>
                <li><a href="#">17oz Latte Mug</a>
                </li>
            </ul>
        </li>
        <li><a href="#">Device Cases</a>

            <ul>
                <li><a href="#">Smartphones</a>
                </li>
                <li><a href="#">Tablets</a>
                </li>
                <li><a href="#">iPods</a>
                </li>
            </ul>
        </li>
        <li><a href="#">Photo Gifts</a>

            <ul>
                <li><a href="#">Keychains</a>
                </li>
                <li><a href="#">Mousepads</a>
                </li>
                <li><a href="#">Playing Cards</a>
                </li>
                <li><a href="#">Puzzles</a>
                </li>
                <li><a href="#">T-Shirts</a>
                </li>
            </ul>
        </li>
    </ul>
</div>

CSS

#menu {
    position: relative;
}
#navbar {
    position: absolute;
    margin: 0;
    padding: 0;
    z-index: 999;
    width: 100%;
    background-color: #F6F6F6;
}
#navbar li {
    list-style: none;
    float: left;
    width: 16.6%;
    background-color: #F6F6F6;
    text-align: center;
    color:#9a9999;
    height:40px;
}
#navbar li a {
    display: block;
    padding: 3px 8px;
    text-transform: uppercase;
    text-decoration: none;
    color: #999;
    font-weight: bold;
}
#navbar li a:hover {
    color: #000;
}
#navbar li ul {
    opacity:0;
    top:0px;
    position:absolute;
    background-color:black;
    z-index: -100;
    left: 0;
    width: 100%;
    /*pointer-events:none;*/
    -webkit-transition: all 0.2s ease 3s;
    -moz-transition: all 0.2s ease-in-out;
    -ms-transition: all 0.2s ease-in-out;
    -o-transition: all 0.2s ease-in-out;
    transition: all 0.2s ease 1s;
}
#navbar li ul li {
    background-color:black;
    color:white;
    font-size:0.8em;
    width:14.1%;
}
#navbar li ul li a {
    color:white!important;
}
#navbar li:hover ul {
    opacity:1;
    background-color:black;
    position: absolute;
    display: inline;
    top:40px;
    left: 0;
    width: 100%;
    margin: 0;
    padding: 0;
    z-index:-100;
    /*pointer-events:auto;*/
    /*animation: fadein 0.2s;
    -webkit-animation: fadein 0.2s;
    -moz-animation: fadein 0.2s;*/
}
#navbar * {
}
@-webkit-keyframes fadein {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}
#navbar li:hover li, #navbar li.hover li {
    float: left;
    background-color:black;
}
#navbar li:hover li a, #navbar li.hover li a {
    color: #FFF;
}
#navbar li li a:hover {
    color: #357;
}

Answer 1

我建议查看“CSS, How do I center horizontal menu and submenu?”

Shaun 的answer 很不错。看看他的 jsfiddle。