:root{
    --color1: #333;
    --color2: #3498db;
}
*{
  margin: 0;
  padding: 0;
}
h1{
  text-align: center;
  color: #fff;
  background-color: var(--color1);
  padding: 20px 10px;
}
#contenido{
    display: flex;
    flex-direction: column;
}
.caja{
    display: flex;
}
.cajaSigno{
    display: flex;
    flex-direction: column;
    align-items: center;
    border: 1px solid var(--color1);
    width: 300px;
    margin: 5px;
    border-radius: 5px;
}
.cajaDescripcion{
    display: none;
    border: 1px solid var(--color1);
    width: 80%;
    margin: 5px;
    border-radius: 5px;
}
.fechas{
    text-align: center;
    background-color: var(--color1);
    color: white;
    width: 150px;
    border-radius: 5px;
    margin: 5px 0px;
    padding: 2px;
}
footer{
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 50px;
    background-color: var(--color1);
    color: white;
    text-align: center;
    padding: 10px;
}
footer a{
    color: var(--color2);
    text-decoration: none;
}
footer a:visited{
    color: #657043;
}