JSFiddle - React, Tailwind, and code Playground

HTML

<div class="downloadButtons">
			<div class="download-button-wrapper">
					<div id="dd" class="desktopBackground downloadFontIcons" tabindex="1">DESKTOP
						<ul class="dropdown">
							<li><a href="#">2560 x 1440</a></li>
							<li><a href="#">1800 x 900</a></li>
						</ul>
					</div>
			</div>
				
			<div class="download-button-wrapper">
					<div id="de" class="tabletBackground downloadFontIcons" tabindex="1">PHONE
						<ul class="dropdown">
							<li><a href="#">640 x 960</a></li>
							<li><a href="#">1136 x 640</a></li>
							<li><a href="#">720 x 1280</a></li>
							
						</ul>
					</div>
			</div>	
			
			
			<div class="download-button-wrapper">
					<div id="df" class="phoneBackground downloadFontIcons" tabindex="1">TABLET
						<ul class="dropdown">
							<li><a href="#">2560 x 1600</a></li>
							<li><a href="#">2048 x 1536</a></li>
						</ul>
					</div>
			</div>
		<div style="clear:both"></div>
		</div>

CSS

.downloadButtons{
	display: block;
	width: 780px;
	height: 200px;
	margin-left: 40px;
	margin-top: 30px;
}

/* GLOBALS - Dropdowns*/
.downloadFontIcons{
	/* Size and position */
    position: relative; /* Enable absolute positionning for children and pseudo elements */
	width: 184px;
	height: 44px;
    margin: 0 auto;
	text-align: center;
	line-height: 44px;
	margin-right: 68px;
	font-size: .7em;
	color: #9ea7b3;
    background-color: #F9FAFC;
    cursor: pointer;
    outline: none;
	border: 1px solid #eaedf1;
}	
.downloadFontIcons .dropdown{
	/* Size & position */
    position: absolute;
    top: 110%;
    left: 0px;
    right: 0px;

    /* Styles */
    background: white;
    -webkit-transition: all 0.3s ease-out;
	-webkit-transition-delay: 0s;
    -moz-transition: all 0.3s ease-out;
	-moz-transition-delay: 0s;
    -ms-transition: all 0.3s ease-out;
    -o-transition: all 0.3s ease-out;
	-o-transition-delay: 0s;
    transition: all 0.3s ease-out;
	transition-delay: 0s;
    list-style: none;

    /* Hiding */
    opacity: 0;
    pointer-events: none;
}

::selection {
    background: transparent; 
}

::-moz-selection {
    background: transparent; 
}

.download-button-wrapper {
    *zoom: 1;
	float: left;
}

.downloadFontIcons  .dropdown li a {
    display: block;
	height: 44px;
    text-decoration: none;
    color: #9ea7b3;
    -webkit-transition: all 0.3s ease-out;
	-webkit-transition-delay: 0s;
    -moz-transition: all 0.3s ease-out;
	-moz-transition-delay: 0s;
    -ms-transition: all 0.3s ease-out;
    -o-transition: all 0.3s ease-out;
	-o-transition-delay: 0s;
    transition: all 0.3s ease-out;
	transition-delay: 0s;
}


/* Hover state */
.downloadFontIcons .dropdown li:hover a {
    color: #FFFFFF;
	background-color:#FF562A;
}

/* Active state */

.downloadFontIcons.active .dropdown {
    opacity: 1;
    pointer-events: auto;
}

/* No CSS3 support */

.no-opacity       .downloadFontIcons .dropdown,
.no-pointerevents .downloadFontIcons .dropdown {
   ...

JavaScript

function DropDown(el) {
				this.dd = el;
				this.initEvents();
			}
			DropDown.prototype = {
				initEvents : function() {
					var obj = this;

					obj.dd.on('click', function(event){
                        $('.active').not($(this)).removeClass('active');
						$(this).toggleClass('active');
						event.stopPropagation();
					});	
				}
			}

			$(function() {
		
				var dd = new DropDown( $('#dd') );

				$(document).click(function() {
					// all dropdowns
					$('.wrapper-dropdown-2').removeClass('active');
				});

			});

			
			
			$(function() {

				var de = new DropDown( $('#de') );

				$(document).click(function() {
					// all dropdowns
					$('.wrapper-dropdown-2').removeClass('active');
				});

			});
			
			$(function() {

				var df = new DropDown( $('#df') );

				$(document).click(function() {
					// all dropdowns
					$('.wrapper-dropdown-2').removeClass('active');
				});

			});