scroll.js

// Vanilla JavaScript Scroll to Anchor
// @ https://perishablepress.com/vanilla-javascript-scroll-anchor/

(function() {
	scrollTo();
})();

// function scrollTo() {
// 	const links = document.querySelectorAll('.scroll');
// 	links.forEach(each => (each.onclick = scrollAnchors));
// }

function scrollTo() {
	var links = document.getElementsByTagName('a');
	for (var i = 0; i < links.length; i++) {
		var link = links[i];
		if ((link.href && link.href.indexOf('#') != -1) && ((link.pathname == location.pathname) || ('/' + link.pathname == location.pathname)) && (link.search == location.search)) {
			link.onclick = scrollAnchors;
		}
	}
}

function scrollAnchors(e, respond = null) {
	const distanceToTop = el => Math.floor(el.getBoundingClientRect().top);
	e.preventDefault();
	var targetID = (respond) ? respond.getAttribute('href') : this.getAttribute('href');
	const targetAnchor = document.querySelector(targetID);
	if (!targetAnchor) return;
	const originalTop = distanceToTop(targetAnchor);
	window.scrollBy({ top: originalTop, left: 0, behavior: 'smooth' });
	const checkIfDone = setInterval(function() {
		const atBottom = window.innerHeight + window.pageYOffset >= document.body.offsetHeight - 2;
		if (distanceToTop(targetAnchor) === 0 || atBottom) {
			targetAnchor.tabIndex = '-1';
			targetAnchor.focus();
			window.history.pushState('', '', targetID);
			clearInterval(checkIfDone);
		}
	}, 100);
}