#thank-you-buy {
  font-family: "IBMediumItalic";
}

/* MOBILE */
@media (max-width: 600px) {
  #thank-you-buy {
    font-size: calc(1.5 * var(--fsz-mobile));
  }
}

/* DESKTOP */
@media (min-width: 600px) {
  #thank-you-buy {
    font-size: calc(1.5 * var(--fsz-desktop));
  }
}