*{margin:0px;}
header {width:100%;float:left;border-top-right-radius:20px;
		min-height:225px;
		font-size:140%;
		color:marroon;
		background-color:#EDF;}
article{
		width:96%;float:left;
		margin:2%;
		min-height:300px;
		font-size:110%;
		background-color:#EEF;
		}
footer{width:100%;float:left;border-bottom-right-radius:20px;
		min-height:205px;
		font-size:100%;
		border-top:1px solid black;
		background-color:#DDF;}
.colum{float:left;width:20%;min-height:300px;}
.content{float:left;width:60%;background-color:#CCC;}
#contenedor{margin:20px auto; width:80%;}
#principal{width:100%;float:left;box-shadow:5px 5px 5px #000;background-color:#DDF; border-radius:20px;}