JSFiddle - React, Tailwind, and code Playground

HTML

<nav id="main-nav">
    <ul>
        <li class="current"><a href="#"><span>Home</span></a>
        </li>
        <li><a href="#"><span>Menu</span></a>
        </li>
        <li><a href="#"><span>Menu</span></a>
        </li>
        <li><a href="#"><span>Menu</span></a>
        </li>
        <li><a href="#"><span>Menu</span></a>
        </li>
        <li><a href="#"><span>Menu</span></a>
        </li>
    </ul>
</nav>

CSS

#main-nav > ul {
    overflow: hidden;
    margin-top: 50px;
}
#main-nav > ul > li {
    float: left;
    overflow: hidden;
    padding: 20px;
    font-size: 18px;
    margin-left: -35px;
}
#main-nav > ul > li:first-child {
    margin-left: 0px;
    border-radius: 10px;
}
#main-nav > ul > li > a {
    color: #444;
    text-decoration: none;
    overflow: hidden;
    display: block;
    -moz-transform: rotate(20deg);
    -o-transform: rotate(20deg);
    -webkit-transform: rotate(20deg);
    background: #bbb;
    margin-bottom: -100px;
    margin-top: -70px;
    height: 150px;
    border-left: 1px solid white;
}
#main-nav > ul > li:first-child > a {
    border-radius: 10px;
    border-left: 0;
}
#main-nav > ul > li > a > span {
    overflow: hidden;
    display: block;
    -moz-transform: rotate(-20deg);
    -o-transform: rotate(-20deg);
    -webkit-transform: rotate(-20deg);
    padding: 0 20px;
    margin-top: 57px;
}
#main-nav > ul > li > a:hover {
    background: #aaa;
}
#main-nav > ul > li.current > a {
    background: #000;
    color: #fff;
}