酷炫的响应式导航栏

* {
    margin: 0;
    padding: 0;
}
html {
    /*background-color: #000;*/
}
.container {
    margin: 30px auto;
    width: 90%;
}
.menu {
    height: 58px;
}



/* general styles */
.menu, .menu ul {
    list-style: none; /*去掉li标签前面的圈圈*/
    padding: 0;
    margin: 0;
}
.menu li {
    /*线性渐变*/
    background: -moz-linear-gradient(#292929, #252525);
    background: -ms-linear-gradient(#292929, #252525);
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #292929), color-stop(100%, #252525));
    background: -webkit-linear-gradient(#292929, #252525);
    background: -o-linear-gradient(#292929, #252525);
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#292929', endColorstr='#252525');
    -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr='#292929', endColorstr='#252525')";
    background: linear-gradient(#292929, #252525);

    /*上下边框的颜色等的设置*/
    border-bottom: 2px solid #181818;
    border-top: 2px solid #303030;
    min-width: 160px;
}
.menu > li {
    /*成行显示——浮动*/
    display: block;
    float: left;
    position: relative;
}
.menu > li:first-child {
    border-radius: 5px 0 0;
}
.menu a {
    border-left: 3px solid rgba(0, 0, 0, 0);
    color: #808080;
    display: block;
    font-family: 'Lucida Console';
    font-size: 18px;
    line-height: 54px;
    padding: 0 25px;
    text-decoration: none;  /*去掉a标签下面的横线*/
    text-transform: uppercase;  /*字体大写*/
}
/* 鼠标放上后的样式 */
.menu li:hover {
    background-color: #1c1c1c;
    background: -moz-linear-gradient(#1c1c1c, #1b1b1b);
    background: -ms-linear-gradient(#1c1c1c, #1b1b1b);
    background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #1c1c1c), color-stop(100%, #1b1b1b));
    background: -webkit-linear-gradient(#1c1c1c, #1b1b1b);
    background: -o-linear-gradient(#1c1c1c, #1b1b1b);
    filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#1c1c1c', endColorstr='#1b1b1b');
    -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr='#1c1c1c', endColorstr='#1b1b1b')";
    background: linear-gradient(#1c1c1c, #1b1b1b);

    border-bottom: 2px solid #222222;
    border-top: 2px solid #1B1B1B;
}
.menu li:hover > a {
    border-radius: 5px 0 0 0;
    border-left: 3px solid #C4302B;
    color: #C4302B;
}



/* submenu styles */
/* 初始状态设置 */
.submenu {
    left: 0;
    max-height: 0;
    position: absolute;
    top: 100%;
    z-index: 0;

    -webkit-perspective: 400px;
    -moz-perspective: 400px;
    -ms-perspective: 400px;
    -o-perspective: 400px;
    perspective: 400px;
}
.submenu li {
    opacity: 0;

    -webkit-transform: rotateY(90deg);
    -moz-transform: rotateY(90deg);
    -ms-transform: rotateY(90deg);
    -o-transform: rotateY(90deg);
    transform: rotateY(90deg);

    -webkit-transition: opacity .4s, -webkit-transform .5s;
    -moz-transition: opacity .4s, -moz-transform .5s;
    -ms-transition: opacity .4s, -ms-transform .5s;
    -o-transition: opacity .4s, -o-transform .5s;
    transition: opacity .4s, transform .5s;
}
/* 放上后 a标签变成白色 */
.menu .submenu li:hover a {
    border-left: 3px solid #454545;
    border-radius: 0;
    color: #ffffff;
}
.menu > li:hover .submenu, .menu > li:focus .submenu {
    max-height: 2000px;
    z-index: 10;
}
.menu > li:hover .submenu li,
.menu > li:focus .submenu li {
    opacity: 1;

    -webkit-transform: none;
    -moz-transform: none;
    -ms-transform: none;
    -o-transform: none;
    transform: none;
}



/* CSS3 delays for transition effects */
.menu li:hover .submenu li:nth-child(1) {
    -webkit-transition-delay: 0s;
    -moz-transition-delay: 0s;
    -ms-transition-delay: 0s;
    -o-transition-delay: 0s;
    transition-delay: 0s;
}
.menu li:hover .submenu li:nth-child(2) {
    -webkit-transition-delay: 50ms;
    -moz-transition-delay: 50ms;
    -ms-transition-delay: 50ms;
    -o-transition-delay: 50ms;
    transition-delay: 50ms;
}
.menu li:hover .submenu li:nth-child(3) {
    -webkit-transition-delay: 100ms;
    -moz-transition-delay: 100ms;
    -ms-transition-delay: 100ms;
    -o-transition-delay: 100ms;
    transition-delay: 100ms;
}
.menu li:hover .submenu li:nth-child(4) {
    -webkit-transition-delay: 150ms;
    -moz-transition-delay: 150ms;
    -ms-transition-delay: 150ms;
    -o-transition-delay: 150ms;
    transition-delay: 150ms;
}
.menu li:hover .submenu li:nth-child(5) {
    -webkit-transition-delay: 200ms;
    -moz-transition-delay: 200ms;
    -ms-transition-delay: 200ms;
    -o-transition-delay: 200ms;
    transition-delay: 200ms;
}
.menu li:hover .submenu li:nth-child(6) {
    -webkit-transition-delay: 250ms;
    -moz-transition-delay: 250ms;
    -ms-transition-delay: 250ms;
    -o-transition-delay: 250ms;
    transition-delay: 250ms;
}
.menu li:hover .submenu li:nth-child(7) {
    -webkit-transition-delay: 300ms;
    -moz-transition-delay: 300ms;
    -ms-transition-delay: 300ms;
    -o-transition-delay: 300ms;
    transition-delay: 300ms;
}
.menu li:hover .submenu li:nth-child(8) {
    -webkit-transition-delay: 350ms;
    -moz-transition-delay: 350ms;
    -ms-transition-delay: 350ms;
    -o-transition-delay: 350ms;
    transition-delay: 350ms;
}

.submenu li:nth-child(1) {
    -webkit-transition-delay: 350ms;
    -moz-transition-delay: 350ms;
    -ms-transition-delay: 350ms;
    -o-transition-delay: 350ms;
    transition-delay: 350ms;
}
.submenu li:nth-child(2) {
    -webkit-transition-delay: 300ms;
    -moz-transition-delay: 300ms;
    -ms-transition-delay: 300ms;
    -o-transition-delay: 300ms;
    transition-delay: 300ms;
}
.submenu li:nth-child(3) {
    -webkit-transition-delay: 250ms;
    -moz-transition-delay: 250ms;
    -ms-transition-delay: 250ms;
    -o-transition-delay: 250ms;
    transition-delay: 250ms;
}
.submenu li:nth-child(4) {
    -webkit-transition-delay: 200ms;
    -moz-transition-delay: 200ms;
    -ms-transition-delay: 200ms;
    -o-transition-delay: 200ms;
    transition-delay: 200ms;
}
.submenu li:nth-child(5) {
    -webkit-transition-delay: 150ms;
    -moz-transition-delay: 150ms;
    -ms-transition-delay: 150ms;
    -o-transition-delay: 150ms;
    transition-delay: 150ms;
}
.submenu li:nth-child(6) {
    -webkit-transition-delay: 100ms;
    -moz-transition-delay: 100ms;
    -ms-transition-delay: 100ms;
    -o-transition-delay: 100ms;
    transition-delay: 100ms;
}
.submenu li:nth-child(7) {
    -webkit-transition-delay: 50ms;
    -moz-transition-delay: 50ms;
    -ms-transition-delay: 50ms;
    -o-transition-delay: 50ms;
    transition-delay: 50ms;
}
.submenu li:nth-child(8) {
    -webkit-transition-delay: 0s;
    -moz-transition-delay: 0s;
    -ms-transition-delay: 0s;
    -o-transition-delay: 0s;
    transition-delay: 0s;
}

以上是样式，接下来看对应的html内容：

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>xxy so cool</title>
    <link href="css/css.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div class="container" id="main" role="main">
    <ul class="menu">
        <li><a href="#">Home</a></li>
        <li><a href="#s1">Menu 1</a>
            <ul class="submenu">
                <li><a href="#">Submenu a</a></li>
                <li><a href="#">Submenu b</a></li>
                <li><a href="#">Submenu c</a></li>
                <li><a href="#">Submenu d</a></li>
                <li><a href="#">Submenu e</a></li>
                <li><a href="#">Submenu f</a></li>
                <li><a href="#">Submenu g</a></li>
                <li><a href="#">Submenu h</a></li>
            </ul>
        </li>
        <li class="active"><a href="#s2">Menu 2</a>
            <ul class="submenu">
                <li><a href="#">Submenu a</a></li>
                <li><a href="#">Submenu b</a></li>
                <li><a href="#">Submenu c</a></li>
                <li><a href="#">Submenu d</a></li>
                <li><a href="#">Submenu e</a></li>
                <li><a href="#">Submenu f</a></li>
                <li><a href="#">Submenu g</a></li>
                <li><a href="#">Submenu h</a></li>
            </ul>
        </li>
        <li><a href="#">Menu 3</a>
            <ul class="submenu">
                <li><a href="#">Submenu a</a></li>
                <li><a href="#">Submenu b</a></li>
                <li><a href="#">Submenu c</a></li>
                <li><a href="#">Submenu d</a></li>
                <li><a href="#">Submenu e</a></li>
                <li><a href="#">Submenu f</a></li>
                <li><a href="#">Submenu g</a></li>
                <li><a href="#">Submenu h</a></li>
            </ul>
        </li>
        <li><a href="#">Menu 4</a></li>
        <li><a href="#">Back to tutorial</a></li>
    </ul>
</div>
</body>
</html>

来源：http://www.cnblogs.com/xinxingyu/p/4794544.html