1<ul class="art-menu">
 2{%- for page in site.pages -%}
 3    {%- assign pagedir = page.dir | remove_first: "/" | split: "/" -%}
 4    {%- include pic-path.html -%}
 5    {%- if pagedir.first == "art" and pagedir.size > 1 -%}
 6    <li class="art-category">
 7        <a class="link-mask" href="{{ page.url }}">{{ page.title }}</a>
 8        <div class="thumbnail">
 9            <img src="{{ artpics.first }}">
10        </div>
11    </li>
12    {% endif %}
13{%- endfor -%}
14</ul>