{# ABOUTME: Detail identity partial — ISBN, language, and series fields. #}
{# ABOUTME: Renders only when at least one identity field is set. #}
{% if book.metadata.isbn or book.metadata.language or book.metadata.series %}
<section class="section" aria-labelledby="detail-identity">
    <h2 id="detail-identity">Identity</h2>
    <dl class="metadata-grid">
        {% if book.metadata.isbn %}
        <dt>ISBN</dt>
        <dd>{{ book.metadata.isbn }}</dd>
        {% endif %}
        {% if book.metadata.language %}
        <dt>Language</dt>
        <dd>{{ book.metadata.language }}</dd>
        {% endif %}
        {% if book.metadata.series %}
        <dt>Series</dt>
        <dd>
            <a href="{{ url_for('web.series_detail', series_name=book.metadata.series) }}">{{ book.metadata.series }}</a>
            {%- if book.metadata.series_index is not none %} #{{ '%g'|format(book.metadata.series_index) }}{% if series_total %} of {{ series_total }}{% endif %}{% endif %}
        </dd>
        {% endif %}
    </dl>
</section>
{% endif %}