화면 스크롤 로드 체크 - new IntersectionObserver

    const io = new IntersectionObserver((entries) => {
      entries.forEach((entry) => {
        if (entry.isIntersecting) {
            var sectionName = $(entry.target).attr("class");
            var subGubun = sectionName.split(" ")[1];
            //console.log( "active.class", subGubun );
              $(entry.target).addClass('active').trigger("activeClass");
            onSearch(subGubun);
        }
      });
    });

    document.querySelectorAll("section").forEach((item) => {
      io.observe(item);
    });