Responsive jQuery restaurant menu system

Question

I have a working restaurant menu system - as the user selects a menu it slides into view. The build is responsive, and I've used the 'Debounced Resize() jQuery Plugin'. However, in implementing the responsive code, I feel my code has become clunky, and it needs refactoring.

The hope here is that I'll receive some constructive criticism and some pointers on how to improve my code, which will in turn grow my knowledge base.

HTML

<section id="menu">
    <div class="menu-container">

        <ul class="menu__nav">
            <li class="menu__nav-item"><a href="#menu-name-1">Menu Title 1</a></li>
            <li class="menu__nav-item"><a href="#menu-name-2">Menu Title 2</a></li>
            <li class="menu__nav-item"><a href="#menu-name-2">Menu Title 2</a></li>
        </ul>

        <!-- Menu 1 -->
        <div id="#menu-name-1" class="menu__main cf">

            <h2 class="menu__course-title">Menu Title 1</h2>

            <div class="menu__col-wrap">
                <div class="menu__col">
                    <div class="menu__col">

                        <div class="menu__subcol">
                            <!-- The Menu -->
                        </div>

                        <div class="menu__subcol">
                            <!-- The Menu -->
                        </div>

                        <div class="menu__subcol">
                            <!-- The Menu -->
                        </div>

                    </div>
                </div>
            </div>

            <div class="menu__image"></div>

        </div>

        <!-- Menu 2 etc... -->

    </div>
</section>

jQuery

$(window).smartresize(function () {

    var $mmenu = $('.menu__main');

    if ($mmenu.length > 0) {

        var $mnav = $('.menu__nav'),
            $mnav_a = $mnav.find('a'),
            m = parseInt($mnav.outerHeight(true), 10),
            $contain = $mmenu.closest('.menu-container'),
            h = 0,
            l = 0;

        // check and store if .active element exists
        var active = $mmenu.not(':first').is('.active');

        // if it doesn't exists
        if (!active) {
            $mmenu.hide() // hide all
                .removeClass('active') // remove the active class from any that have it
                .first() // select the first only
                .addClass('active') // give it the active class
                .show(); // and show it 

            $mnav_a.eq(0).addClass('active');

        $mmenu.each(function(z) {

            var $this = $(this);

            $this.css('height','auto');

            $this.css({
                zIndex: z+1,
                position: 'absolute',
                top: m + "px",
                left: l,
                height: (parseInt($this.outerHeight(false), 10) + m) + "px"
            });

            l = l - $this.outerWidth();

        });

        $contain.height($mmenu.eq(0).height());

    } else {

        $mmenu.each(function(z) {

            var $this = $(this);

            $this.css('height','auto');

            $this.css({
                zIndex: z+1,
                position: 'absolute',
                top: m + "px",
                height: (parseInt($this.outerHeight(false), 10) + m) + "px"
            });

        });

        var $new_contain = $('.menu__main.active').height();

        $contain.height($new_contain);

    }

        $mnav_a.on('click', function(e) {

            e.preventDefault();
            var $this = $(this);

            if (!$this.hasClass('active')) {

                $mmenu.stop(true, true);

                $mnav_a.removeClass('active');
                $this.addClass('active');

                $mmenu.filter($('.active'))
                    .removeClass('active')
                    .fadeOut(250)
                    .animate({left:l+"px"}, 250);

                var $target = $mmenu.filter($this.attr('href'));

                $contain.animate({height:$target.height()}, 250);

                $target.addClass('active')
                    .fadeIn(250)
                    .animate({left:0}, 250);
            }

            $this.blur();
        });
    }
});

Working Example

CodePen

Answer 1

Some of your code is redundant. These two lines are mutually exclusive. Especially since you add "active" to the first menu item, which is the only one which would satisfy !active.

   if (!active) {
            .removeClass('active') // remove the active class from any that have it

Makes me wonder if the "if (!active)" branch can be removed entirely.

Revised CodePen: http://codepen.io/anon/pen/FHfAi