JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>

	<div id="menu">
		<span class="line"></span>
	</div>
	<div class="menu_back"></div>
	<div class="menu_list">
		<ul class="list">
			<li class="menu_item"><a href="#intro" class="item_link">Home</a></li>
			<li class="menu_item"><a href="#about" class="item_link">About Us</a></li>
			<li class="menu_item"><a href="#services" class="item_link">Services CLICK THIS LINK FRO SCROLL</a></li>
			<li class="menu_item"><a href="#portfolio" class="item_link">Portfolio</a></li>
			<li class="menu_item"><a href="#contact" class="item_link">Contact us</a></li>
		</ul>
	</div>
	<div class="intro_container">
		<a class="anchor" id="intro"></a>
		<div class="video_container">
			<video class="video" autoplay loop>
				<source src="videos/intro.mp4" type='video/mp4; codecs="avc1.42E01E, mp4a.40.2"' />
				<!-- 			<source src="videos/intro.webm" type='video/webm; codecs="vp8, vorbis"' /> -->
			</video>
			<div class="video_pattern"></div>
		</div>
		<div class="logo_c">
			<img src="images/logo.png">
		</div>
		<div class="text_c">
			<div class="text_pusher">
				<span class="intro_text green">Get an awesome website</span>
				<span class="intro_text white">Never been easier</span>
			</div>
		</div>
		<div class="button_c">
			<div class="button_pusher">
				<a href="#services" class="intro_button">SERVICES</a>
				<a href="#contact" class="intro_button">HIRE US NOW</a>
			</div>
		</div>
	</div>
	<div class="about_container">
		<a class="anchor" id="about"></a>
		<span class="about_title">About Us</span>
		<span class="line_white"></span>
		<span class="about_text">"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</span>
		<a href="#" class="about_button">Hire Us</a>
	</div>
	<div class="services_container...

JavaScript

$('a.item_link').click(function(){
  console.log($( $(this).attr('href') ).offset().top);
    $('html, body').animate({
        scrollTop: $( $(this).attr('href') ).offset().top
    }, 500);
    return false;
});