#contenido-principal {
  border-radius: 4px;
  border-style: solid;
  border-color: white;

  background-image: url('/Content/dib/fondo004.png');
  background-repeat: no-repeat;
  background-size: cover;
  /* border-style: solid;
        border-color: red;
        border-radius: 4px;*/
  height: 100%;
  padding: 1em;
  /*      padding-top: 2px;*/
}


#nombre,
#idemail,
#idClave {
  color: black;
  background-color: white;
}

  #nombre:focus,
  #idemail:focus {
    color: yellow;
    background-color: darkblue;
  }

  #nombre:hover,
  #idemail:hover,
  #idClave:hover {
    color: darkblue;
    background-color: lightyellow;
  }