function stickyHeaderObserverCallback(entry) { document .querySelectorAll('[data-ol-plans-v2-table-sticky-header]') .forEach(el => el.classList.toggle('sticky', entry[0].boundingClientRect.bottom > 0) ) } export function setUpStickyHeaderObserver() { const stickyHeaderStopEl = document.querySelector( '[data-ol-plans-v2-table-sticky-header-stop]' ) const observer = new IntersectionObserver(stickyHeaderObserverCallback) observer.observe(stickyHeaderStopEl) }