sassbootstrap.js

$(document).ready(function() {
// When Scrollspy Detects a change
$(window).on("activate.bs.scrollspy", function() {
  var hash = $(".site-nav")
    .find("a.active")
    .attr("href");

  if (hash == "#main-content") {
    $(".site-nav").addClass("inbody");
  } else {
    $(".site-nav").removeClass("inbody");
  }
});

$(window).trigger("scroll");
$(window).on("scroll", function() {
  var top = $(window).scrollTop();
  $("#page-hero")
    .css("transform", "translate3d(0px, " + top / 5 + "px, 0px)")
    .css("opacity", 1 - Math.max(top / (window.innerHeight * 0.7), 0));
});
});