* {
    margin: 0;
    padding: 0;
    font-family: Arial, Helvetica, sans-serif;
}

header, .principal, footer{
    width: 80%;
    margin:auto;
}

header h1 {
    color: white;
    margin: 10px 20px;
    padding: 10px;
}

.principal .articulos {
    background:rgb(156, 222, 248);
    width:59%;
    float:left;
    margin-right: 1%;
    margin-bottom: 10px;
}

.principal .articulos article {
    padding: 5px;
}

.principal .articulos h2 {
    color:blue;
}

article p {
    text-align: justify;
}

header {
    background:rgb(8, 78, 158) ;
}

aside {
    background: cyan;
    width: 32%;
    float:left;
    padding:5px;
    box-sizing: border-box;
    margin-bottom: 10px;
}

aside img{
    display:block;
    margin:auto;
}

footer {
    color: white;
    background: black;
    clear:both;
}

footer p {
    text-align: center;
}