const observer = new IntersectionObserver((entries) => {
         entries.forEach((entry) => {
              console.log(entry)
              if (entry.isIntersecting) {
                   entry.target.classList.add('show');
              } else {
                   entry.target.classList.remove('show');
              }
            });
        });
const hiddenElements = document.querySelectorAll('.hidden');
hiddenElements.forEach((el)=> observer.observe (el));