JSFiddle - React, Tailwind, and code Playground

HTML

<body>
		<div id="wrapper">
			<div id="cinta">
				<div id="img_cinta"><img src="../img/logo-gnc.png" height="50px"></img></div>
					<center>
						<div id="menu_cinta"><br>
							<a href="#">GNC Gestion de Informacion</a>
						</div>
					<center>
			</div>
		    <br>
	<div id="main">
	
			<div id="sidebar">
				<div id="sb_title">Menu</div>
				<div id="sidebar_menu" class="menu">
					<ul>
							<li><a rel="nofollow" href="../../"  target="_parent" class="estilo1">Inicio</a></li>
							<li ><a rel="nofollow" href="#" target="_parent" class="estilo1">Ventas</a>
								<ul>
									<li ><a href="#" class="estilo2">Opcion 1</a></li>
									<li ><a href="#" class="estilo2">Opcion 2</a></li>
									<li ><a href="#" class="estilo2">Opcion 3</a></li>
								</ul>
							</li>
							<li ><a rel="nofollow" href="#" target="_parent" class="estilo1">Inventarios</a>
								<ul>
									<li ><a href="#" class="estilo2">Opcion 1</a></li>
									<li ><a href="#" class="estilo2">Opcion 2</a></li>
									<li ><a href="#" class="estilo2">Opcion 3</a></li>
								</ul>
							</li>
					  </ul>   
				</div>
			</div>
	
		<div id="container">
			
		</div> <!-- /container -->
	</div> <!-- /main -->
		</div><!-- End Wrapper -->

	</body>

CSS

/* Reseter */
* {
	margin:0;
	padding:0;
}

/* Body */
body{
	background-image:url("../img/fondo.gif");
	font-family: Tahoma, Geneva, sans-serif;
}

/* Contenido */
#wrapper{
	/*width: 935px; medida original */
	width: auto;
	margin: 0 auto;
	height: auto;
	position: relative;
}

/* cinta general*/
#cinta{
	width: auto;
	height: 50px;
	background-color: #2a2a2a;
}

#cinta img{
	width:auto;
	float:left;
}

#menu_cinta{
	width:auto;
	height:50x;
}

#menu_cinta a {
	padding:7px 14px;
	font-size: 20px;
	color: #aeaeae;	
	text-decoration: none;
	font-weight: bold;
}

#main{
	width:auto;
	height: auto;
}

#menu_cinta a:hover{
	color: #fff;
}
/*End cinta general*/

#container {
	float: left;
	width:auto;
	height: auto;
}

/*Sidebar de paginas no index*/
#sidebar{
	float: left;
	height: auto;
	clear: both;
	margin-bottom: 30px;
}

#sb_title {
	height: 20px;
	padding: 9px 30px;
	font-size: 18px;
	color: #666666;
	background: url(../img/sidebar_box_top.jpg) no-repeat top left;
}

#sidebar_menu {
	width: 150px;
}

.menu ul {
	list-style: none;
}

.menu ul li {
	display: list-item;
	padding: 10px 0 0;
	margin: 0;
	display: block;
	height: 36px;
	background: url(../img/menu_divider.jpg) left bottom no-repeat;
}

.menu ul li ul {
	display: none;
}

.menu ul li a {
	font-size: 15px;
	color: #2a2a2a;	
	text-decoration: none;
	display: block;
	height: 36px;
	padding: 0 0 0 30px;
	font-weight: bold;
	outline: none;
	border: none;
}

#sidebar_menu ul li a.estilo1:hover {
	background: url(../img/img_bot.jpg) left bottom no-repeat;
}

a.estilo2:hover { 
	background: url(../img/img_bot2.jpg) left bottom no-repeat;
}

.menu ul li:hover ul, .menu ul li:focus ul {
	float:right;
	display: block;
	position: relative;
	width: 160px;
	border: solid 1px #fff;
	border-top: none;

	}
	

/*End sidebar */

#contenido{
	margin: 20px;
}
/* Caja */
.caja:focus{
border: 2px solid #000000;
background:#f5f5f5;
}

/* Link  */
#link {color: #FFFFFF;}
#link:hover {color: #FFFFFF;}
#link:visited{color:...