JSFiddle - React, Tailwind, and code Playground

HTML

<div class="menu">
                <ul>
                    <li>Item</li>
                    <li>Item</li>
                    <li>Item</li>
                    <li>Item</li>
                    <li>Item</li>
                </ul>
            </div>

CSS

.menu
{
    float: left;
    color:white;
}

.menu > ul
{
    list-style: none;
    text-align: center;
    padding: 0;
    margin:0;
}

.menu > ul > li
{
    display: block;
    position: relative;
    padding: 60% 5px;
    background-color: #048990;
    cursor: pointer;
    transition: all 0.5s;
}

.menu > ul > li:hover
{
    background-color: #444;
    color: white;
}

.menu > ul > li:hover .menu > ul > li::after
{
    opacity: 0;
}

.menu > ul > li:active
{
    background-color: #444;
}

.menu >ul >li:after {
    content:"";
    background: #FFF;
    position: absolute;
    bottom: 0;
    left: 7%;
    height: 1px;
    width: 86%;
}

.menu > ul > li:last-child:after {
    display: none;
}