Parallax Effect 03 - 스크롤링 효과 : 숨김 메뉴

{
   let nowScroll = true;
        let lastScroll = 0;

        function scrollProgress(){
            nowScroll = true;

            setInterval(()=>{
                if(nowScroll){
                    nowScroll = false;
                    hasScroll()
                }
            },300);

        }

        function hasScroll(){
            let scrollTop = window.pageYOffset || document.documentElement.scrollTop || window.scrollY            
            
             if(scrollTop < lastScroll){ //lastScroll이 scrollTop보다 클때 show를 추가하고 아니면 show를 삭제
                 document.querySelector("#parallax__nav").classList.add("show")
            }else {
                document.querySelector("#parallax__nav").classList.remove("show")
            }
                lastScroll = scrollTop;
        }

        window.addEventListener("scroll", scrollProgress)

        document.querySelectorAll("#parallax__nav a").forEach(el => {
            el.addEventListener("click", e =>{
                e.preventDefault();
                document.querySelector(el.getAttribute("href")).scrollIntoView({behavior: "smooth"})
            })
        })
}