html {
  font-size: 1em;
  line-height: 1.5em;
  font-family: "Verdana", Helvetica, sans-serif;
}

body {
  margin: 0;
  background: #f3f3f3;
}

.encabezado {
  text-align: center;
  background: #006699;
  border-bottom: 0.1em solid silver;  
  padding: 0.5em;
  }


.footer-principal {
  text-align: center;
  background: #006699;
  border-bottom: 0.1em solid silver;  
  padding: 1em;
  }

.principal {
  max-width: 900px;
  margin: auto;
  padding: 1em;
}

.caja1, .caja2, .caja4 {
  background: #fff;
  border: 0.1em solid gray;
  padding: 1em;
  margin: 1em;
  box-shadow: 0 0 0.1em 0.01em black;
} 


.caja3 {
  background: #fff;
  border: 0.08em solid gray;
  padding: 1em;
  margin: 1em;
  box-shadow: 0 0 0.1em 0.01em black;
  border-radius: 15px;
} 

.caja1 h2 {
  font-family: 'Verdana', sans-serif;
  color: darkblue;
  text-shadow: 0.03em 0.03em 0.01em #000;
  letter-spacing: 0.03em;
}
.caja1 p, ol {
  font-family: 'Verdana', sans-serif;
  color: darkblue;
}

.caja2 h1 {
  font-family: 'Verdana', sans-serif;
  color: darkblue;
  text-shadow: 0.03em 0.03em 0.01em #000;
  letter-spacing: 0.03em;
}

.caja2 h2 {
font-family: 'Roboto', sans-serif;
font-size: 1.2em;
text-align:center;
color: darkblue;
}

#foto {
	top:0;
	display:block;
	margin:0 auto 0 auto;
    height:100%;
    width:100%;
    max-width:400px;
    max-height:400px;
  border-radius: 50px;
}

.caja2 p {
  text-align: justify;
  font-family: 'Roboto', sans-serif;
  font-size: 0.9em;
  color: darkblue;
  }

.caja3, .caja4 h2 {
  font-family: 'Verdana', sans-serif;
  color: darkblue;
  text-shadow: 0.03em 0.03em 0.01em #000;
  letter-spacing: 0.03em;
}

#img {
	top:0;
	display:block;
	margin:0 auto 0 auto;
    height:100%;
    width:100%;
    max-width:350px;
    max-height:600px;
}
.articulo {
  margin-top: 2em;
}

.solucion h2 { font-size: 1.5em; }

.solucion h3 {
  font-family: 'Tahoma', sans-serif;
  font-size: 1em;
  color: darkblue;
  
}

.solucion iframe {
    width:100%;
    max-width:600px;
    max-height:692px;
}
.texto {
  text-align: center;
  font-family: 'Arial', sans-serif;
  font-size: 0.7em;
  color: black;
  }
#caracteres {
	list-style: none; margin: 0px 0px 10px; padding: 0px;
}
#caracteres li {
	padding: 10px 5px; border-radius: 3px; border: 1px solid rgb(226, 226, 226); border-image: none; line-height: 18px; overflow: auto; margin-bottom: 0px; display: block; min-height: 18px; box-shadow: 0px 5px 5px -5px #000;
}	
.degradado {
	background: linear-gradient(rgb(33, 66, 99) 0%, rgb(254, 254, 254) 70%);
}