img.uno {
  opacity: 0.5;
}
img.dos {
  opacity: 0.2;
}
img.tres {
  opacity: 1;
}

img.cuatro {
  opacity: 0.5;
}

img.cuatro:hover {
  opacity: 1;
}

div {
  background-color: #aaa704;
  padding: 10px;
}

div.first {
  opacity: 0.1;
}

div.second {
  opacity: 0.3;
}

div.third {
  opacity: 0.6;
}

div.background {
  background: url(../imagenes/fondo.jpg) repeat;
  border: 2px solid black;
}

div.transbox {
  margin: 30px;
  background-color: #137eaf;
  border: 1px solid black;
  opacity: 0.6;
}

div.transbox p {
  margin: 5%;
  font-weight: bold;
  color: #000000;
}
