.testimonial {
  --font-size: 20;
  display: -ms-flexbox;
  display: flex;
  -ms-flex-direction: column;
      flex-direction: column;
  text-align: center;
}
.testimonial cite {
  margin-top: 20px;
  font-weight: bold;
  text-transform: uppercase;
}
.testimonial p {
  font-size: calc(var(--font-size) / var(--base) * 1rem);
}

@media (min-width: 992px) {
  .testimonial {
    --font-size: 30;
  }
  .testimonial p {
    line-height: 1.9;
  }
}