<button class="btn bg-primary">
        primary
      </button>

      <button class="btn bg-secondary">
        secondary
      </button>

      <button class="btn bg-default">
        default
      </button>

      <button class="btn bg-accent">
        Accent
      </button>

      <button class="btn outline-primary">
        primary
      </button>

      <button class="btn outline-secondary">
        secondary
      </button>

      <button class="btn outline-default">
        default
      </button>

      <button class="btn outline-accent">
        Accent
      </button>