* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: Arial, sans-serif;
  padding: 15px;
  background-color: white;
}

nav {
  border: 2px dashed goldenrod;
  width: 28%;
  float: left;
  padding: 15px;
  min-height: 520px;
}

nav h2 {
  font-size: 18px;
  margin-bottom: 20px;
  color: gray;
}


nav article {
  border: 2px dotted greenyellow;
  padding: 15px;
  margin-bottom: 55px;
  color: black;
}


.contenido-derecho {
  width: 70%;
  float: right;
}


header {
  border: 2px dashed orangered;
  padding: 15px;
  margin-bottom: 15px;
}


header span:first-child {
  float: left;
}

header span:last-child {
  float: right;
}


header:after {
  content: "";
  display: table;
  clear: both;
}


main {
  border: 2px dashed rgb(155, 230, 230);
  padding: 15px;
}


.fila-widgets {
  margin-bottom: 15px;
}


.fila-widgets::after {
  content: "";
  display: table;
  clear: both;
}

.fila-widgets section {
  border: 2px dashed purple;
  width: 48%;
  float: left;
  padding: 20px;
  min-height: 180px;
}


.fila-widgets section:first-child {
  margin-right: 4%;
}

section.full-width {
  border: 2px dashed rgb(158, 26, 158);
  padding: 20px;
  min-height: 180px;
  clear: both;
}