javascript - make everything responsive

//--------------------------------------------------------------
    //  Ico
    //  When you have iFrame with fixed height and the client wants it responsove,
    //  this is how you (t)roll
    //  1200 is the breakpoint
    //  $holderElement is the wrapper element
    //  You need jQuery and TweenLite included
    //--------------------------------------------------------------
    var isResponsive = true;

    if (isResponsive) {
        var $holderElement = $('.app__holder');
        var $window = $(window);
        var isMobile = $window.width() < 1200;
        var scaleRatio = 1;

        TweenLite.set($holderElement, {transformOrigin: '0 50%'});

        $(window).on('resize', function () {
            var winWidth = $window.width();
            if (winWidth < 1200) {
                isMobile = true;
                scaleRatio =  winWidth / 1200;
            } else {
                if (isMobile) {
                    isMobile = false;
                    scaleRatio = 1;
                }
            }

            TweenLite.set($holderElement, {scale: scaleRatio});

        }).trigger('resize');
    }