Código HTML:
 <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>The classified advertising website</title> <link rel="stylesheet" href="style.css" /> <link rel="stylesheet" href="menu.css"> </head> <body> <div id="container"> <div class="topbar"><div class="topbaractions">Login Register | Contact Us</div></div> <div style="clear: both"></div> <section class="top"> <div class="logo"><img src="seacell.png"/> </div> <div><label for="show-menu" class="show-menu">Show menu</label> <input type="checkbox" id="show-menu" role="button"> <ul id="menu"> <li class="categorylist"><a href="index.html">HOME</a></li> <li class="categorylist"><a href="browse.html">BROWSE ALL ADS</a></li> <li class="categorylist"><a href="post.html">POST NEW AD</a></li> <li class="categorylist"><a href="myad.html">MY AD</a></li> </ul></div> </section> <div style="clear: both"></div> <div class="add">Post an AD</div> <div style="clear: both"></div> <div id="menu-category"> <span>Select a group</span> <ol id="sub-category"> <li>Antiques, Art, Collectables</li> <li>Automotive</li> <li>Baby & Children</li> <li>Boats & Jet Skis</li> <li>Business Services</li> <li>Community</li> <li>Cothing & Jewellery</li> <li>Books, Music & Games</li> <li>Friends & Partners</li> <li>Home & Garden</li> <li>Pets</li> <li>Real Estate</li> <li>Jobs</li> <li>Sport & Fitness</li> <li>Tickets</li> </ol> </div> <div style="clear: both"></div> </div><!-- div contenedot --> <footer> Copyright 2014 </footer> </body>
Código:
  
 html{height:100%;}
body{
	font-family: 'PT Sans', sans-serif;
	background-color:#fff;
	margin:0;
	height:100%;}
	
#container{
	margin: 10px auto 8px auto;
	width: 90%;
	height:100%;
	margin-top:10px;
	background-color:#EBEBEB;}
/* --------------------------- POST AN AD -------------------------*/
.add{
	color:#000;
	height:3%;
	padding:1em;
	text-align:center;
	background-color:#ffcc00;
	box-shadow:rgba(0,0,0,0.1) 0 5px  0 0;
	}
/* --------------------------- LOGIN -------------------------*/
.top{
	margin-top:0;}
.topbar{
	background-color:#CCC;
	color:#fff;
	padding-top:1em;
	padding-bottom:1em;
	width:100%;}
.topbaractions{
	color:#333;
	text-align:right;
	padding-right:5%;}
/* --------------------------------- LOGO -------------------------*/	
.logo{
	float:left;}
.logo img{
	max-width:100%;
	padding:1em;}
/* --------------------------- CATEGORYES -------------------------*/
#menu-category{
			background: #d2691e ;
			position:absolute;
			color: white;
			margin-top: 30px;
			margin-left:20px;
			font-weight: bolder;
			border-radius:14px 15px 0 0;
			cursor: pointer;
			padding: 10px;
			width: 300px;}
#sub-category{
	position:relative;
			background: white;
			cursor: pointer;	
			font-weight: lighter;
			padding: 0;			
			margin: 10px -10px 0 -10px;
			width: 320px;}
#sub-category li{		
			color: #333;
			cursor: pointer;	
			padding: 10px;
			margin: 0;
			list-style: none;
			-webkit-transition: all 0.3s;
			-moz-transition: all 0.3s;
			-o-transition: all 0.3s;
			-ms-transition: all 0.3s;
			transition: all 0.3s;}		
#sub-category li:hover{		
			border-left: solid 5px #a98701;
			background: #ffcc00;
			font-weight: bolder;}
			
/* --------------------------- FOOTER -------------------------*/
footer{
	position:relative;
	text-align:center;
	padding:1em;
	background-color:#999;
	width:88%;
	margin:0 auto;}
/* --------------------------- @MEDIAS -------------------------*/
@media (max-width: 1024px) {
.logo{float:none; text-align:center;}
.logo img{ padding:0 0 1em 0;}
.topbaractions{text-align:center;}
.add{margin-top:3em;}
}
 
@media (max-width: 480px) {
#menu-category{	float:none; text-align:center;	margin:15PX auto 0 auto;}
}
@media (max-width: 340px) {
#menu-category{width:200px;  margin:10px auto 10px auto; text-align:center;}
#sub-category{width:220px;}
}
 
 



