body{ 
text-align: left; /*alineación hor del texto*/ 
font-family: Tahoma, Arial, Geneva, sans-serif; /*tipo de fuente*/
color:#FFFFFF; /*color de fuente*/
}

#cabecera{ 
width: 100%; /*ancho*/
height: 100px; /*alto*/
text-align: center; /*alineación hor del texto*/
margin-bottom: 0px; /*margen externo inferior*/
background-color:#E50000; /*color de fondo*/
float: top; /*ubicación relativa del bloque*/
}

/* Add a black background color to the top navigation */
.topnav {
    position: relative;
    background-color: #333;
    overflow: hidden;
}

/* Style the links inside the navigation bar */
.topnav a {
  float: left;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}

/* Change the color of links on hover */
.topnav a:hover {
  background-color: #FF0000;
  color: black;
}

/* Add a color to the active/current link */
.topnav a.active {
  background-color: #4CAF50;
  color: white;
}

/* Centered section inside the top navigation */
.topnav-centered a {
  float: none;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

/* Right-aligned section inside the top navigation */
.topnav-right {
  float: right;
}

}
/* Responsive navigation menu - display links on top of each other instead of next to each other (for mobile devices) */
@media screen and (max-width: 600px) {
  .topnav a, .topnav-right {
    float: none;
    display: block;
  }

  .topnav-centered a {
    position: relative;
    top: 0;
    left: 0;
    transform: none;
  }
}

section{ 
width: 100%;
height: 720px;
text-align: center;
margin-bottom: 0px; 
background-image: url("fondo.gif");
background-size: 1400px 720px;
opacity: 0.95;
float: right;
}

footer {
    position: center;
    margin-top: 0px;
    height: 80px; 
    clear: both;
    background: #000000;
    text-align: center;
    color: #fff;
	float: center
}