body {
  background: gray;
  color: black;
  font-family: Arial;
  text-align:center;
}

.contenedor{
  width:80%;
  height:100%;
  margin: 0 auto;
  background: white;
  text-align:center;
}

header {
  text-align: center;
  height:1px;
  vertical-align: middle;
  visibility : hidden;
}

section {
  float: left;
  width: 30%;
  text-align:center;
  padding:1%;
    background: white;

}

aside {
  float: right;
  padding:10px;
  width: 65%;
  border-left:1px solid #ddd;
  background: white;
}

footer {
  clear: both;
  text-align:center;
  background:#5c5c8a;
  visibility:hidden;
}

tabla {
  margin-left : 20%;
  width : 100%;
  text-align: center;
}

table {
  font-size: 18px;
  font-family:"arial";
  border-collapse: collapse;
  width:50%;
}

th {
    height: 50px;
}
tr:nth-child(even) {background-color: #f2f2f2}

nav{
  text-align: center;
  width:100%;
  height:10%;
}

nav ul {
  padding-left: 0;
  margin-bottom: 0;
  list-style: none;
  border-bottom: 1px solid #ddd;
  overflow: hidden;
  background-color:#5c5c8a;
}

nav ul li {
  margin-bottom: -1px;
  background-color: #5c5c8a;
  border-right: 1px solid #ccc;
  display:inline;
}

nav ul li a {
  display: inline-block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

nav ul li a:hover {
  background-color: #33334d;
}