silverstripe-webpack/app/client/src/scss/_typography.scss

// Add your site-wide, but not content editor typography styling

.bg-dark {
  h1,
  h2,
  h3,
  h4,
  h5,
  h6,
  .h1,
  .h2,
  .h3,
  .h4,
  .h5,
  .h6,
  .typography,
  a {
    color: $white;
  }
}

.typography {
  @include clearfix;

  @import "./types/editor";

  a.btn-primary {
    color: $white;
  }

  img {
    border: 0;
  }
}