Ejemplo 2. CSS
*{
	margin:0;
	padiing:0;
}

body {
background: #f6f5f5;
font-family: Candara;
color: black;
text-align:left;
}

header {
	width: 100%;
	max-width: 100%;
	margin: 20px auto;
	color: black;
}

h3{
	color: #093a42;
}

header nav{
	background: #1ec4dc;
	overflow:hidden;

}

header nav ul{
	list-style: none;
}

header nav ul li {
	float:left;
}

header nav ul li a {
	padding: 10px 20px;
	display:block;
	color: white;
	text-decoration:none;
}

header nav ul li a:hover{
	background:  #8ee1ed;
}				

.main .articulos {
	width: 68.5%;
	margin-right:1.5%;
	float:left;
	background: #f6f5f5;
	text-align: justify;
}

.main .articulos article{
	padding:20px;
	background:#ffe4b2;
	margin-bottom:20px;

}

aside{
	display: inline-block;
	vertical-align: top;
	text-align: center;
	background:#ace8ff;
	width: 350px;
	margin: 0px auto;
	padding:10px;
	border-radius: 5px;
	color: black;
}


footer {
	background: grey;
	color: white;
	clear:both;
	padding:10px 0px;
	text-align:center;
}

.pie2{
	color: black;
	background:#cda0b1;

}


img {
	margin: 10px;
	border-radius:5px;
	}