Tạo menu đa cấp theo chiều ngang bằng CSS3 và jQuery

1. HTML

<nav id="cbp-hrmenu" class="cbp-hrmenu">
    <ul>
        <li>
            <a href="#">Products</a>
            <div class="cbp-hrsub">
                <div class="cbp-hrsub-inner"> 
                    <div>
                        <h4>Learning & Games</h4>
                        <ul>
                            <li><a href="#">Catch the Bullet</a></li>
                            <li><a href="#">Snoopydoo</a></li>
                            <!-- ... -->
                        </ul>
                    </div>
                    <div>
                        <h4>Utilities</h4>
                        <ul>
                            <li><a href="#">Gadget Finder</a></li>
                            <li><a href="#">Green Tree Express</a></li>
                            <li><a href="#">Green Tree Pro</a></li>
                            <li><a href="#">Wobbler 3.0</a></li>
                            <li><a href="#">Coolkid</a></li>
                        </ul>
                    </div>
                    <div>
                        <!-- ... -->
                    </div>
                </div><!-- /cbp-hrsub-inner -->
            </div><!-- /cbp-hrsub -->
        </li>
        <li><!-- ... --></li>
        <li><!-- ... --></li>
        <!-- ... -->
    </ul>
</nav>

2. CSS

.cbp-hrmenu {
    width: 100%;
    margin-top: 2em;
    border-bottom: 4px solid #47a3da;
}
 
/* general ul style */
.cbp-hrmenu ul {
    margin: 0;
    padding: 0;
    list-style-type: none;
}
 
/* first level ul style */
.cbp-hrmenu > ul,
.cbp-hrmenu .cbp-hrsub-inner {
    width: 90%;
    max-width: 70em;
    margin: 0 auto;
    padding: 0 1.875em;
}
 
.cbp-hrmenu > ul > li {
    display: inline-block;
}
 
.cbp-hrmenu > ul > li > a {
    font-weight: 700;
    padding: 1em 2em;
    color: #999;
    display: inline-block;
}
 
.cbp-hrmenu > ul > li > a:hover {
    color: #47a3da;
}
 
.cbp-hrmenu > ul > li.cbp-hropen a,
.cbp-hrmenu > ul > li.cbp-hropen > a:hover {
    color: #fff;
    background: #47a3da;
}
 
/* sub-menu */
.cbp-hrmenu .cbp-hrsub {
    display: none;
    position: absolute;
    background: #47a3da;
    width: 100%;
    left: 0;
}
 
.cbp-hropen .cbp-hrsub {
    display: block;
    padding-bottom: 3em;
}
 
.cbp-hrmenu .cbp-hrsub-inner > div {
    width: 33%;
    float: left;
    padding: 0 2em 0;
}
 
.cbp-hrmenu .cbp-hrsub-inner:before,
.cbp-hrmenu .cbp-hrsub-inner:after {
    content: " ";
    display: table;
}
 
.cbp-hrmenu .cbp-hrsub-inner:after {
    clear: both;
}
 
.cbp-hrmenu .cbp-hrsub-inner > div a {
    line-height: 2em;
}
 
.cbp-hrsub h4 {
    color: #afdefa;
    padding: 2em 0 0.6em;
    margin: 0;
    font-size: 160%;
    font-weight: 300;
}
 
/* Examples for media queries */
 
@media screen and (max-width: 52.75em) { 
 
    .cbp-hrmenu {
        font-size: 80%;
    }
 
}
 
@media screen and (max-width: 43em) { 
 
    .cbp-hrmenu {
        font-size: 120%;
        border: none;
    }
 
    .cbp-hrmenu > ul,
    .cbp-hrmenu .cbp-hrsub-inner {
        width: 100%;
        padding: 0;
    }
 
    .cbp-hrmenu .cbp-hrsub-inner {
        padding: 0 2em;
        font-size: 75%;
    }
 
    .cbp-hrmenu > ul > li {
        display: block;
        border-bottom: 4px solid #47a3da;
    }
 
    .cbp-hrmenu > ul > li > a { 
        display: block;
        padding: 1em 3em;
    }
 
    .cbp-hrmenu .cbp-hrsub { 
        position: relative;
    }
 
    .cbp-hrsub h4 {
        padding-top: 0.6em;
    }
 
}
 
@media screen and (max-width: 36em) { 
    .cbp-hrmenu .cbp-hrsub-inner > div {
        width: 100%;
        float: none;
        padding: 0 2em;
    }
}

3. JAVASCRIPT

var cbpHorizontalMenu = (function() {
 
    var $listItems = $( '#cbp-hrmenu > ul > li' ),
        $menuItems = $listItems.children( 'a' ),
        $body = $( 'body' ),
        current = -1;
 
    function init() {
        $menuItems.on( 'click', open );
        $listItems.on( 'click', function( event ) { event.stopPropagation(); } );
    }
 
    function open( event ) {
 
        if( current !== -1 ) {
            $listItems.eq( current ).removeClass( 'cbp-hropen' );
        }
 
        var $item = $( event.currentTarget ).parent( 'li' ),
            idx = $item.index();
 
        if( current === idx ) {
            $item.removeClass( 'cbp-hropen' );
            current = -1;
        }
        else {
            $item.addClass( 'cbp-hropen' );
            current = idx;
            $body.off( 'click' ).on( 'click', close );
        }
 
        return false;
 
    }
 
    function close( event ) {
        $listItems.eq( current ).removeClass( 'cbp-hropen' );
        current = -1;
    }
 
    return { init : init };
 
})();