JSFiddle - React, Tailwind, and code Playground

HTML

<nav class="floatfix">      
            <ul>
                <li><a href="index.php">Home</a>
                   <ul>
                       <li><a href="index2.php">£3.99 T-Shirts</a></li>
                       <li><a href="index3.php">£4.99 T-Shirts</a></li>
                   </ul>
                </li>
                <li><a href="login.php">Log In</a></li>
                <li><a href="#">Account</a></li>
                <li><a href="feedback.php">Feedback</a></li>
                <li><a href="#">Checkout</a></li>
                <li><a href="aboutus.php">About Us</a></li>
                </ul>
        </nav>

CSS

ul {
    font-family: Arial, Verdana;
    font-size: 14px;
    margin: 0;
    padding: 0;
    list-style: none;
}
ul li {
    display: block;
    position: relative;
    float: left;
}
li ul {
    display: none;
}
ul li a {
    display: block;
    text-decoration: none;
    color: #ffffff;
    border-top:25px solid #ffffff;
    padding: 5px 15px 5px 15px;
    background: #1e7c9a;
    margin-left: 1px;
    white-space: nowrap;
}
ul li a:hover {
background: #3b3b3b;
}
li:hover ul {
    display: block;
    position: absolute;
}
li:hover li {
    float: none;
    font-size: 11px;
}
li:hover a { background: #3b3b3b; }
li:hover li a:hover {
    background: #1e7c9a;
}