script.js

var navMenuAnchorTags = document.querySelectorAll(".nav-menu a");
var interval;

for (var i = 0; i < navMenuAnchorTags.length; i++) {
	navMenuAnchorTags[i].addEventListener("click", function (event) {
		event.preventDefault();
		var targetSectionID = this.textContent.trim().toLowerCase();
		console.log(this.textContent);
		var targetSection = document.getElementById(targetSectionID);
		console.log(targetSection);
		//    interval = setInterval(scrollVertically, 20, targetSection);

		interval = setInterval(function () {
			scrollVertically(targetSection, targetSectionID);
		}, 20);
	});
}

function scrollVertically(targetSection, targetSectionID) {
	var targetSectionCoordinates = targetSection.getBoundingClientRect();
	if (targetSectionCoordinates.top <= 0) {
		clearInterval(interval);
		return;
	}
	if (targetSectionID === "contact" && targetSectionCoordinates.top <= 80) {
		clearInterval(interval);
		return;
	}
	window.scrollBy(0, 50);
}