JSFiddle - React, Tailwind, and code Playground

HTML

<div id="menu">
	<ul>
		<li class="active">
			<a class="nb" title="Úvod" href="/sk/uvod/">Úvod</a>
		</li>
		<li>
			<a title="ponuka" href="/sk/sprava1/">ponuka</a>
		</li>
		<li>
			<a title="farba" href="/sk/sprava2/">Dfarba</a>
		</li>
	</ul>
</div>

CSS

/* Zobrazenie v riadku a odsadenie menu */
 #menu ul li {
    list-style: none;
    display: inline;
    padding: 0px 10px;
    margin: 0px 10px;
}

/* Reset laveho odsadenia prvej polozky menu */
 #menu ul li:first-child {
    margin-left: 0px;
}

/* Vzhlad menu */
 #menu {
    width: 100%;
    background: -webkit-linear-gradient(top, rgb(51, 51, 51) 0%, rgb(105, 105, 105) 100%);
    background: -o-linear-gradient(top, rgb(51, 51, 51) 0%, rgb(105, 105, 105) 100%);
    background: -ms-linear-gradient(top, rgb(51, 51, 51) 0%, rgb(105, 105, 105) 100%);
    background: -moz-linear-gradient(top, rgb(51, 51, 51) 0%, rgb(105, 105, 105) 100%);
    background: linear-gradient(to bottom, rgb(51, 51, 51) 0%, rgb(105, 105, 105) 100%);
    height: 50px;
}

#menu ul li a {
    text-decoration: none;
    color: #fff;
    line-height: 50px;
}

#menu ul li.active a {
    color: red;
}