JSFiddle - React, Tailwind, and code Playground

HTML

<div class="bg-div">
    <img class="logo-img" src="SENCOR_Logo.jpg" width="130" height="45">
    <nav>
        <ul>
            <li><a href="#">Monitoring</a></li>
            <li><a href="#">Process</a></li>
            <li><a href="#">Post and Create Email/Excel</a></li>
            <li><a href="#">Reports</a>
                <ul>
                    <li><a href="#">Re-Create Email</a></li>
                    <li><a href="#">Merge and Post</a></li>
                    <li><a href="#">Create Excel Report</a></li>
                </ul>
                </li>
                <li>
            <li><a href="#">Tools</a>
                <ul>
                    <li><a href="#">Users</a></li>
                    <li><a href="#">Folder Path</a></li>
                    <li><a href="#">Change Folder Path</a></li>
                </ul>
                </li>
            <li><a href="#">Sales</a></li>
        </ul>
    </nav>
</div>

CSS

body{
    margin: 0;
    padding: 0;
    font-size: 15px;
    font-family: "Lucida Grande", "Helvetica Nueue", Arial, sans-serif;
}
nav {
    background-color: #333;
    border: 1px solid #333;
    color: #fff;
    display: block;
    margin: 0;
}
nav ul{
    margin: 0;
    padding: 0;
    list-style: none;
}
nav ul li {
    margin: 0;
    display: inline-block;
    list-style-type: none;
    transition: all 0.2s;
}

nav > ul > li > a {
    color: #aaa;
    display: block;
    line-height: 2em;
    padding: 0.5em 2em;
    text-decoration: none;

}

nav li > ul{
    display : none;
    margin-top:1px;
    background-color: #bbb;

}

nav li > ul li{
    display: block;
}

nav  li > ul li a {
    color: #111;
    display: block;
    line-height: 2em;
    padding: 0.5em 2em;
    text-decoration: none;
}

nav li:hover {
    background-color: #666;
}
nav li:hover > ul{
    position:absolute;
    display : block;
}

-----------
.logo-img{

    position: fixed;
    margin: 10px 15px 15px 10px;
    left: 0;
    display:inline;
}

.bg-div{
    background:#333;
    height: 50px;
}

.bg-div nav {
    position: fixed;
    display:inline;
    right: 0;
}