Bootstrap responsive font size scss

rfs.scss

@media (max-width: 1200px) {
  legend {
    font-size: calc(1.275rem + 0.3vw);
  }
  h1,
  .h1 {
    font-size: calc(1.375rem + 1.5vw);
  }
  h2,
  .h2 {
    font-size: calc(1.325rem + 0.9vw);
  }
  h3,
  .h3 {
    font-size: calc(1.3rem + 0.6vw);
  }
  h4,
  .h4 {
    font-size: calc(1.275rem + 0.3vw);
  }
  .display-1 {
    font-size: calc(1.725rem + 5.7vw);
  }
  .display-2 {
    font-size: calc(1.675rem + 5.1vw);
  }
  .display-3 {
    font-size: calc(1.575rem + 3.9vw);
  }
  .display-4 {
    font-size: calc(1.475rem + 2.7vw);
  }
  .close {
    font-size: calc(1.275rem + 0.3vw);
  }
}

Thank to
https://christianoliff.com/blog/bootstrap-with-rfs