function(){
          preloader.style.display='none';
          scroll.style.overflow='scroll';
      }
      const backTopElement = document.getElementById("back-top-div");
      const minScolledAmountToBackTop = 800;

      window.addEventListener("scroll", () => {
        if (window.scrollY < minScolledAmountToBackTop) {
          backTopElement.classList.add("hidden");
        } else {
          backTopElement.classList.remove("hidden");
        }
      });

      const backTop = () => {
        window.