$base-font-size: 14px;
  $base-line-height: 21px;

  @include establish-baseline;

  body {
    @include adjust-font-size-to($base-font-size);
  }

  h1 {
    @include adjust-font-size-to(31px);
  }

  /* This translates to */

  html {
    font-size: 87.5%;
    line-height: 1.5em;
  }

  body {
    font-size: 1em;
    line-height: 1.5em;
  }

  h1 {
    font-size: 2.21429em;
    line-height: 1.35484em;
  }