JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
    <div id="topmenu">
      <ul>
  	    <li class="active"><a href="#">Пункт 1</a></li>
  	    <li><a href="#">Пункт 2</a></li>
  	    <li><a href="#">Пункт 3</a></li>
  	  </ul>
    </div>
</div>

CSS

#wrapper {
	width: 980px;
	height: 100%;
	margin: 0 auto;
}

#topmenu {
	width: 980px;
	position: relative;
	height: 55px;
}

#topmenu ul {
	padding: 0;
	margin: auto;
	list-style: none;
	font-family: "Trebuchet MS";
	font-size: 21px;
	text-decoration: none;
	color: #fff;
}

#topmenu ul:after {
	clear: both;
	content: ".";
	display: block;
	height: 0;
	visibility: hidden;
}

#topmenu li {
	text-align: center;
	display: block;
	float: left;
	margin: 0 2px 0 2px;
	background: #ff6699;
	opacity: 0.8;
	width: 135px;
}

#topmenu .active {
	background: #cc3399;
	opacity: 0.8;
	height: 55px;
}

#topmenu a {
	text-decoration: none;
	display: block;
	color: #fff;
	height: 45px;
	padding: 10px 0;
	-moz-box-sizing: border-box;
	-webkit-box-sizing: border-box;
	box-sizing: border-box;
}

#topmenu li:hover {
	background: #cc3399;
	opacity: 0.8;
	height: 55px;
}