discourse/app/assets/stylesheets/common/form-kit/_section.scss

.form-kit__section {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  width: 100%;

  &.form-kit__actions {
    flex-direction: row;
    gap: 1rem;
  }
}

.form-kit__section-title {
  margin: 0;
  font-size: var(--font-up-1-rem);
}