JSFiddle - React, Tailwind, and code Playground

HTML

<nav>
   <div id="menubar" class=" collapse navbar-collapse row">
                        <ul id="dropdownNavbar" class="nav navbar-nav">
                            <li class="dropdown">
                                <button type="button" class="btn btn-primary dropbtn"><span class="glyphicon glyphicon-time"></span> Time Card
                                    <span class="caret"></span></button>
                                <div class="dropdown-content">
                                    <a id="showTimeCard" href="#">My Time Card</a>
                                    <a href="#">Sub Menu 2</a>
                                    <a href="#">Sub Menu 3</a>
                                    <a href="#">Sub Menu 4</a>
                                    <a href="#">Sub Menu 5</a>
                                </div>
                            </li>
                            <li class="dropdown">
                                <button type="button" class="btn btn-primary dropbtn"><span class="glyphicon glyphicon-stats"></span> Project
                                    <span class="caret"></span></button>
                                <div class="dropdown-content">
                                    <a href="#">Sub Menu 1</a>
                                    <a href="#">Sub Menu 2</a>
                                    <a href="#">Sub Menu 3</a>
                                </div>
                            </li>
                            <li class="dropdown">
                                <button type="button" class="btn btn-primary dropbtn"><span class="glyphicon glyphicon-user"></span> HR Links
                                    <span class="caret"></span></button>
                                <div class="dropdown-content">
                                    <a href="#">Sub Menu 1</a>
                                    <a href="#">Sub Menu 2</a>
                                </div>
                            </li>
     ...

CSS

.dropdown {
    float: left;
    padding-right:1px;
}

.dropbtn{
    border: 0px;
    height:30px;
    border-radius: 0px 10px;
}
li button, .dropbtn {
    display: inline-block;
    color: white;
    text-align: center;
}

li button:hover, .dropdown:hover .dropbtn {
    background-color: #12A5F4;
}

.dropbtn.active {
    background: #12A5F4;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: #e8f3f4;
    min-width: 100%;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.1);
    z-index: 10;
}

.navbar-header{
    overflow: visible;
    z-index: 1;
}

.dropdown-content a {
    color: black;
    padding: 5px 10px;
    display: block;
    text-align: left;
}

.dropdown-content a:hover {
    background-color: #d8dee2
}

.dropdown:hover .dropdown-content {
    display: block;
}

#menubar{
    padding-top: 5px;
    overflow: visible;
    z-index: 10;
    padding-left:0px;
    padding-right: 0px;
    margin: 0px;

}

#dropdownNavbar{
    margin: 0px;
}

.navbar-toggle{
    background-color: #3382d5;
}
.navbar-toggle span{
    background-color: white;
}