{# 卡片头部宏：头像 + 昵称 + 日期 + 标题 #}
{% macro card_header(nickname, icon_url, date, title) %}
<div class="card-header">
  {% if icon_url %}
    <div class="avatar-wrap">
      <img class="avatar" src="{{ icon_url }}" alt="avatar">
    </div>
  {% else %}
    <div class="avatar-placeholder">👤</div>
  {% endif %}
  <div class="header-info">
    <div class="nickname">{{ nickname or "未知用户" }}</div>
    <div class="date">{{ date }}</div>
    <div class="card-title">{{ title }}</div>
  </div>
</div>
{% endmacro %}