 class="fa fa-exchange"></i>
                Flip Card
            </a>
            &nbsp;
            &nbsp;
            <a href="{{ url_for('mark_unknown', card_id=card.id, card_type=card_type) }}" class="btn btn-success btn-lg">
                <i class="fa fa-check"></i>
                I Unknow It
            </a>
            &nbsp;
            &nbsp;
            <a href="{{ url_for('memorize_known', card_type=card_type) }}" class="btn btn-primary btn-lg">
                Next Card
                <i c