JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="nav_menu">
    <li><a class="nav_menu_link">Home</a></li>
    <li class="nav_menu_link_drop_1">
        <a class="nav_menu_link">DropDown 1</a>
    </li>
        <div id="content1" style="display: none;">
            <ul style="padding: 20px; height: auto;">
                Contetn1
            </ul>
    </div>
    <li class="nav_menu_link_drop_2">
        <a class="nav_menu_link">DropDown 2 <i class="arrow down"></i></a></li>
    <div id="content2" style="display: none;">
        <ul style="padding: 20px; height: auto;">
            Contetn2
        </ul>
    </div>
</ul>
<script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>

CSS

* {   
margin: 0;
padding: 0;
}
    #nav_menu {
        position: absolute;
        display: block;
        height: 80px;
        width: 100%;
        background: orange;
    }
    #nav_menu li {
        list-style-type: none;
        text-decoration: none;
        vertical-align: middle;
        height: 80px;
        display: inline-block;
        position: relative;
    }
    .nav_menu_link {
        color: black;
        font-size: 18px;
        height: 0;
        font-family: Arial;
        vertical-align: baseline;
        position: relative;
        display: inline-block;
        height: auto;
        padding: 29px;
    }
    .nav_menu_link:hover {
        background: rgba(0, 0, 0, 0.4);
        color: #FFF;
        transition: all .2s;
    }
    .nav_menu_link:hover .arrow.down {
        border-top-color: #FFF;
    }

    #content1:hover {
        display: block !important;
        width: 100%;
        height: auto !important;
        position: absolute;
    }
    #content2:hover {
        display: block !important;
        width: 100%;
        height: auto !important;
        position: absolute;
    }
    #content1, #content2 {
        width: 100%;
        height: auto;
        background: gray;
        display: none;
        position: absolute;
    }

JavaScript

var link1 = $(".nav_menu_link_drop_1");
var link2 = $(".nav_menu_link_drop_2");
var content1 = $('#content1');
var content2 = $('#content2');

$(link1).hover(
    function(){ 
        $(content1).slideDown(350);
    },
    function(){
        $(content1).slideUp(350);
    }
);

$(link2).hover(
    function(){ 
        $(content2).slideDown(350);
    },
    function(){
        $(content2).slideUp(350);
    }
);