{% extends "!layout.html" %}

{% block extrahead %}
  {{ super() }}
  {% if operon_language_url %}
  <link rel="alternate" hreflang="{{ 'zh' if operon_language_label == '中文' else 'en' }}" href="{{ operon_language_url }}">
  <meta name="operon-language-url" content="{{ operon_language_url }}">
  <meta name="operon-language-label" content="{{ operon_language_label }}">
  {% endif %}
{% endblock %}