css3和jquery实现的可折叠导航菜单(适合手机网页)

<nav class="nav" role="navigation" style="height: 195px;">
        <ul class="nav-items">
            <li><a target=_blank href="http://www.w2bc.com">Home</a></li>
            <li><a target=_blank href="http://www.w2bc.com">About</a></li>
            <li><a target=_blank href="http://www.w2bc.com">Clients</a></li>
            <li><a target=_blank href="http://www.w2bc.com">Contact Us</a></li>
        </ul>
    </nav>
    <header style="-webkit-transform: translate3d(0px, 195px, 0px);">
  <button class="menu-button-target active" data-ic-class="button-trigger">
      <span class="menu-button"></span>
  </button>
  Example Header
</header>
    <section>
        <article>
        </article>
        <article>
        </article>
        <article>
        </article>
        <article>
        </article>
        <article>
        </article>
    </section>

*
        {
            box-sizing: border-box;
        }
        body
        {
            font-family: "HelveticaNeue-Light" , "Helvetica Neue Light" , "Helvetica Neue" , Helvetica, Arial, "Lucida Grande" , sans-serif;
            font-weight: 300;
        }
        nav
        {
            position: fixed;
            -webkit-transform: translate3d(0, 0, 0);
            left: 0;
            transition: all 0.4s ease;
            width: 100%;
            background: #34495e; 
            height: 0;
            overflow: hidden;
            transition-delay: 0.25s; 
            
        }
        .active nav
        {
            transition-delay: 0s;
        }
        nav ul
        {
            width: 95%;
            margin: 0 auto;
        }
        nav ul li
        {
            padding: 5px;
            border-bottom: 1px solid white; 
        }
        nav ul li:nth-child(1) a
        {
            transition-delay: 0.1s;
        }
        nav ul li:nth-child(2) a
        {
            transition-delay: 0.15s;
        }
        nav ul li:nth-child(3) a
        {
            transition-delay: 0.2s;
        }
        nav ul li:nth-child(4) a
        {
            transition-delay: 0.25s;
        }
        nav ul li:last-child
        {
            border: none;
        }
        nav ul li a
        {
            transition: all 0.2s cubic-bezier(0.455, 0.03, 0.515, 0.955);
            position: relative;
            display: block;
            text-decoration: none;
            color: white;
            font-size: 18px;
            padding: 10px;
            -webkit-transform: translate3d(100px, 0, 0);
            opacity: 0;
        }
        .active nav ul li a
        {
            -webkit-transform: translateX(0);
            opacity: 1;
        }
        header
        {
            transition: all 0.4s ease;
            -webkit-transform: translate3d(0, 0, 0);
            left: 0;
            width: 100%;
            position: fixed;
            background: #27ae60;
            color: white;
            padding: 20px;
            text-align: center;
            font-size: 20px;
            transition-delay: 0.25s;
        }
        .active header
        {
            transition-delay: .08s;
        }
        section
        {
            background: #f5f5f5;
            padding-top: 80px;
        }
        article
        {
            background: white;
            height: 500px;
            width: 95%;
            border-radius: 3px;
            margin: 0 auto 20px auto;
            border: 1px solid #e4e4e4;
        }
        .menu-button-target
        {
            background: transparent;
            border: none;
            outline: none;
            cursor: pointer;
            position: absolute;
            z-index: 200;
            left: 10px;
            height: 50px;
            top: 50%;
            margin-top: -23px;
            webkit-tap-highlight-color: rgba(0, 0, 0, 0);
        }
        .menu-button-target.active .menu-button
        {
            transition: background .2s ease;
            background-color: transparent;
        }
        .menu-button-target.active .menu-button:before, .menu-button-target.active .menu-button:after
        {
            transition: top .3s ease, -webkit-transform .3s .2s ease;
        }
        .menu-button-target.active .menu-button:before
        {
            top: 0;
            -webkit-transform: rotate(45deg);
        }
        .menu-button-target.active .menu-button:after
        {
            top: 0;
            -webkit-transform: rotate(-45deg);
        }
        .menu-button
        {
            position: relative;
            top: 50%;
            left: 0;
            display: block;
            width: 40px;
            height: 4px;
            margin-top: -2px;
            background-color: white;
            border-radius: 10px;
            transition: background .2s .2s;
        }
        .menu-button:before, .menu-button:after
        {
            content: "";
            display: block;
            position: absolute;
            width: 100%;
            height: 100%;
            left: 0;
            background-color: white;
            transition: top .3s .2s ease, -webkit-transform .3s ease;
            border-radius: 10px;
            -webkit-transform-origin: 50% 50%;
        }
        .menu-button:before
        {
            top: -10px;
            -webkit-transform: rotate(0deg);
        }
        .menu-button:after
        {
            top: 10px;
            -webkit-transform: rotate(0deg);
        }

var $menuTrigger = $('[data-ic-class="button-trigger"]'),
    $menuOverlay = $('[data-ic-class="overlay"]'),
    $menuItem = $('.menu-item'),
    activeClass = 'active',
    $nav = $('nav'),
    $navULHeight = $('.nav-items').outerHeight(),
    navOpen = false,
    $header = $('header');
 
        var isTouch = false;
        if ($('html').hasClass('touch')) {
            isTouch = true;
        }
 
        function menuFunction() {
            $menuTrigger.toggleClass(activeClass);
 
            if (!navOpen) {
 
                $nav.height($navULHeight);
                navOpen = true;
                $('body').addClass('active');
                $header.css('transform', 'translate3d(0, ' + $navULHeight + 'px, 0)');
 
            } else {
 
                $nav.height(0);
                $header.css('transform', 'translate3d(0, 0, 0)');
                navOpen = false;
                $('body').removeClass('active');
 
            }
        }
 
        if (isTouch) {
            $menuTrigger.on('touchstart', function () {
                menuFunction();
            });
        }
 
        if (!isTouch) {
            $menuTrigger.on('click', function () {
                menuFunction();
            });
        }