JSFiddle - React, Tailwind, and code Playground

HTML

<nav class="clearfix">
		<ul class="clearfix">
			<li><a href="#"><div class="nav-i"><img src="images/nav-icons/1.png"  class="nav-icon"></div> Главная</a></li>
			<li><a href="#"><div class="nav-i"><img src="images/nav-icons/2.png"  class="nav-icon"></div> Спутниковое ТВ</a></li>
			<li><a href="#"><div class="nav-i"><img src="images/nav-icons/3.png"  class="nav-icon"></div> Города</a></li>
			<li><a href="#"><div class="nav-i"><img src="images/nav-icons/4.png"  class="nav-icon"></div> Цены</a></li>
			<li><a href="#"><div class="nav-i"><img src="images/nav-icons/5.png"  class="nav-icon"></div> Контакты</a></li>
			<li><a href="#"><div class="nav-i"><img src="images/nav-icons/6.png"  class="nav-icon"></div> Онлайн-заказ</a></li>	
		</ul>
		<a href="#" id="pull">Меню</a>

	</nav>
  <br><Br><br>
  <h1>заголовок
  </h1>
  
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CSS

h1 {
		font-size: 32px;
		font-weight: 500;
		color: #314255;
		margin: 0 auto;
		text-align: center;
    position: relative;
        }
	
h1:after {
  content: '';
  display: inline-blcok;
  width: 100px;
  height: 2px;
  position: absolute;
  bottom: -5px;
  left: 50%;
  transform: translateX(-50%);
  background: red;
}

  
  
  /* Clearfix */
.clearfix:before,
.clearfix:after {
    content: " ";
    display: table;
}
.clearfix:after {
    clear: both;
}
.clearfix {
    *zoom: 1;
}

/* Основные стили меню */

.nav-icon {
	width: 30px;
}

.nav-i {
	width: 150px;
	margin-top: 8px;
	margin-bottom: 8px;
}

nav {
	height: 75px;
	width: 100%;
	background-color: #314255;
	font-size: 16px;
    position: fixed;
}

  
nav ul {
	padding: 0;
	margin: 0 auto;
	width: 900px;
	height: 40px;
}
nav li {
	display: inline;
	float: left;
}
nav a {
	color: #fff;
	display: inline-block;
	width: 150px;
	text-align: center;
	text-decoration: none;
   height: 75px;
}
nav li a {
	border-right: 1px solid #576979;
	box-sizing:border-box;
	-moz-box-sizing:border-box;
	-webkit-box-sizing:border-box;
}
nav li:last-child a {
	border-right: 0;
}
nav a:hover, nav a:active {
	background-color: #e60d27;
}
nav a#pull {
	display: none;
}

/* Стили для экранов 600px и меньше */
@media screen and (max-width: 900px) {
	nav { 
  		height: auto;
  	}
  	nav ul {
  		width: 100%;
  		display: block;
  		height: auto;
  	}
  	nav li {
  		width: 50%;
  		float: left;
  		position: relative;
  		border-right: 1px solid #576979;
  	}
  	nav li a {
       border-bottom: 1px solid #576979;
		border-right: none;
	}
  	nav a {
	  	text-align: left;
	  	width: 100%;
	  	text-indent: 25px;
  	}
  	
  		nav {
		border-bottom: 0;
	}
	nav ul {
		display: none;
		height: auto;
	}
	nav a#pull {
		display: block;
		background-color: #314255;
		width: 100%;
		height: 60px;
		position: relative;
		line-height: 60px;
	}
		
	nav a#pull:after {
		content:"";
		background: url('../images/nav-icon.png') no-repeat;
		width:...

JavaScript

$(function() {
			var pull 		= $('#pull');
				menu 		= $('nav ul');
				menuHeight	= menu.height();

			$(pull).on('click', function(e) {
				e.preventDefault();
				menu.slideToggle();
			});

			$(window).resize(function(){
        		var w = $(window).width();
        		if(w > 900 && menu.is(':hidden')) {
        			menu.removeAttr('style');
        		}
    		});
		});