.responsive {
  max-width: 100%;
  height: auto;
  margin-left: auto;
  margin-right: auto;
  display: block;  width: 90%;
}
.caja {
  max-width: 100%;
  height: auto;  display: block;

  margin-left: 42px;
  margin-right:42px;
}
.cajatitle {
    margin-top: 6px; 
  }
@media screen and (min-width: 600px) {
  div.caja {
    font-size: 18px;
  }
}

@media screen and (max-width: 600px) {
  div.caja {
    font-size: 12px;
  }
}
@media screen and (min-width: 600px) {
  div.cajatitle {
    font-size: 28px;
  }
}

@media screen and (max-width: 600px) {
  div.cajatitle {
    font-size: 18px;
  }
}
@media screen and (min-width: 600px) {
  div.cajasubtitle {
    font-size: 22px;
  }
}

@media screen and (max-width: 600px) {
  div.cajasubtitle {
    font-size: 16px;
  }
}