<style>

<style>
    .imagen {}

    @media only screen and (max-width: 720px) {
        .imagen {
            display: none;
        }
    }

  div.tarjetas {}

  @media only screen and (max-width: 720px) {
      div.tarjetas {
          display: flex !important;
          flex-direction: column !important;
          justify-content: center !important;
      }
  }
</style>
