JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="toggle">
    <li> <a href="www.gooogle.de">Menu</a>

        <ul id="dropdown" class="dropdown-menu" role="menu">
            <li><a href="www.google.de">2017</a>

            </li>
            <li><a href="#">2012</a>

            </li>
            <li><a href="#">2003</a>

            </li>
        </ul>
    </li>
    <li><a href="www.google.de">Contact</a></li>
</ul>

CSS

#toggle {
    list-style-type: none;
    margin: 0;
    padding:0;
    text-align:left;
    line-height:2.5em;
    font-size: 1.0em;
    text-transform:uppercase;
    font-style:normal;
}
#toggle li {
    padding:0;
    margin:0;
    vertical-align:top;
    float:left;
    position:relative;
}
#toggle li a {
    background-color:#222;
    margin:0 1px 0 0;
    padding:8px 17px;
    color:#fff;
    font-weight:300;
    text-decoration:none;
}
#toggle li ul {
    list-style-type: none;
    left:0;
    position:absolute;
    display: none;
}

JavaScript

$(document).ready(function () {
    $('#toggle li:has(#dropdown)').on('click', function (event) {
        if ($(event.target).parents('#dropdown').length > 0) {
            event.stopPropagation();
        } else {
            event.preventDefault();
        }
        $(this).find('ul').slideToggle();
    });
});