*{margin: 0; padding: 0}
body {
    background-image:url(pepe.gif);
    font-family: "arial";
}
h1 {
    font-family:"arial";
    font-size: 20px;
    font-weight: bold;
}
h2 {
    color: #ffffff;
    font-size: 16px;
}
a {
    text-decoration: none
}
header {
    display: block;
    background-color: rgb(0, 0, 0);
    height: 50px;
    width: 100%;
    margin: 5px;
    padding: 5px;
    position: relative
}
.blanco {color: aliceblue
}

    aside {
  float: left;
  width: 18%;
    height: 250px
  margin: 0 15px 20px 0;
  padding: 15px 0px 0px 15px;
}
main {
    background-color: #c3c3c3;
    opacity: 0.8;
    width: 780px;
    float: left;
     margin: 37px 15px 20px 0;
  padding: 15px 0px 15px 15px;    
}

footer {
    font-family: "arial";
    font-size: 8px; 
    text-align: center;
    position: relative;
    float: left;
    background-color: black;
    padding: 5px 0px 0px 0px;
    width: 100%;
    height: 35PX;
}
header nav ul {
    display: inline-block;
}
header nav ul li {
    text-decoration: none; 
    color:#000;
    list-style-type: none
    
}

.clear {
    clear:both
}