Optimize this code JQuery

Recently I've created a code that rotates objects, the code works more or less, I've cleaned it, but it still looks messy and it's a little buggy. The code works but when you open the Chrome console and close it the code stops working, please help me!

$(document).ready(function(){

        var gradi = [];
        for (var i = 0; i < 6; i++) {
            gradi[i] = 0;
        };

        var scheda = [];
        for (var i = 1; i < 7; i++) {
            scheda[i] = $("main div:nth-child("+i+")").offset().top;
        }

        var schermo = $(window).height();

        $(window).on("scroll", function(){
            var percorso = $(this).scrollTop();
            if (percorso > scheda[1] && percorso < scheda[2]) {
                var quantita = (percorso-scheda[1])/10;
                ruota(1, quantita);
            } else if (percorso > scheda[2] && percorso < scheda[3]) {
                var quantita = (percorso-scheda[2])/10;
                ruota(2, quantita);
            } else if (percorso > scheda[3] && percorso < scheda[4]) {
                var quantita = (percorso-scheda[3])/10;
                ruota(3, quantita);
            } else if (percorso > scheda[4] && percorso < scheda[5]) {
                var quantita = (percorso-scheda[4])/10;
                ruota(4, quantita);
            } else if (percorso > scheda[5] && percorso < scheda[6]) {
                var quantita = (percorso-scheda[5])/10;
                ruota(5, quantita);
            } else {
                $(".hero").css({ transform: "rotateX(0deg)"});
            }
        });

        function ruota(i, n){
            var indice = i-1;
            var opacita = n/110;
            gradi[indice] = n;
            $("main > div:eq("+indice+") > div")
                .css({ transform: "rotateX("+gradi[indice]+"deg)", opacity: 1-opacita });
            $("main > div:eq("+i+") > div")
                .css("transform", "rotateX(0deg)");
        }

});