List links to other articles in the same topic and bold the current article.

gistfile1.html

<style>
  .active { font-weight: bold; }
  .inactive { opacity: 0.5; }
</style>

<ul>
  {% for cur in topic.articles %}
    <li>
      <a class="{% if article.id == cur.id %}active{% else %}inactive{% endif %}" href='{{ cur.public_url }}'>{{ cur.subject_plain | clip:40 }}</a>
    </li>
{% endfor %}
</ul>