JSFiddle - React, Tailwind, and code Playground

HTML

<nav>	<!-- Navigation -->
		<ul id="dropdownMenu">
			<li><a href="#">Home</a></li>
			<li><a href="#">New Article</a></li>
			
			<li><a href="#">Categories</a>
				<ul id="droprightMenu">
					<li><a href="#">All</a>
						<ul id="droprightMenu">
							<li><a href="#">Category 1</a>
								<ul id="droprightMenu">
									<li><a href="#">Category 1.1</a></li>   
									<li><a href="#">Category 1.2</a></li>   
									<li><a href="#">Category 1.3</a></li>   
									<li><a href="#">Category 1.4</a></li>   
								</ul>					
							</li>   
							<li><a href="#">Category 2</a></li>   
							<li><a href="#">Category 3</a></li>   
							<li><a href="#">Category 4</a></li>   
						</ul>					
					</li>  
					<li><a href="#">Manage</a></li>   
				</ul>
			</li>
			
			<li><a href="#">My Profile</a>
				<ul id="droprightMenu">
					<li><a href="#">Login</a></li>   
					<li><a href="#">Edit</a></li>   
					<li><a href="#">My Posts</a></li>   
					<li><a href="#">Logout</a></li>   
				</ul>			
			</li>			
			
			<li><a href="#">Help</a></li>
		</ul>
	</nav>

CSS

/*------------------------------
 = NAVIGATION
 ------------------------------*/

#dropdownMenu {
	background: #efefef; 
	background: linear-gradient(top, #efefef 0%, #bbbbbb 100%);  
	background: -moz-linear-gradient(top, #efefef 0%, #bbbbbb 100%); 
	background: -webkit-linear-gradient(top, #efefef 0%,#bbbbbb 100%); 
	box-shadow: 0px 0px 9px rgba(0,0,0,0.15);
	border-radius: 10px;  
	list-style: none;
	position: relative;  /* allow us to absolutely position the sub menus according to this main nav bar */
	display: block; 
}
	
#dropdownMenu:after {
	content: ""; clear: both; display: block;
}

/*
The individual menu items are styled up with CSS rules added to the <li> and the nested anchor. 
In the browser this will make the link change to a blue gradient background and white text.
*/

#dropdownMenu li {
	float: left;
	display:block;
	line-height:50px;
	text-align:center;
	vertical-align:top;
	width:120px;
}

#dropdownMenu li:hover > ul {   /* reappear sub menus on hover*/
	display: block;
}

#dropdownMenu li a {
	display: block;
	color: #757575; text-decoration: none;
}

#dropdownMenu li:hover {
	background: #4b545f;
	background: linear-gradient(top, #4f5964 0%, #5f6975 40%);
	background: -moz-linear-gradient(top, #4f5964 0%, #5f6975 40%);
	background: -webkit-linear-gradient(top, #4f5964 0%,#5f6975 40%);
}

#dropdownMenu li:hover a {
	color: #fff;
}

#droprightMenu {
	display: none; /* hide the sub menus */
	background: #5f6975; border-radius: 0px; padding: 0;
	position: absolute; top: 100%;
}

#droprightMenu li {
	float: none; 
	border-top: 1px solid #6b727c;
	border-bottom: 1px solid #575f6a;
	position: relative;
	
}
#droprightMenu li ul {
    left:120px;
    top:0px;
}

#droprightMenu li a {
	color: #fff;
}	

#droprightMenu li a:hover {
	background: #4b545f;
}
#droprightMenu li ul {
    left:120px;
    top:0px;
}