Improve JS/CSS selector

Separate layout from tabs, and more friendly to tabs rename (#187)

_layouts/archives.html

@@ -0,0 +1,41 @@
+---
+layout: page
+
+# The Archives of posts.
+# v2.0
+# https://github.com/cotes2020/jekyll-theme-chirpy
+# © 2017-2019 Cotes Chung
+# MIT License
+---
+
+
+<div id="archives" class="pl-xl-2">
+{% for post in site.posts %}
+  {% capture this_year %}{{ post.date | date: "%Y" }}{% endcapture %}
+  {% capture pre_year %}{{ post.previous.date | date: "%Y" }}{% endcapture %}
+  {% if forloop.first %}
+    {% assign last_day = "" %}
+    {% assign last_month = "" %}
+  <span class="lead">{{this_year}}</span>
+  <ul class="list-unstyled">
+  {% endif %}
+    <li>
+      <div>
+        {% capture this_day %}{{ post.date | date: "%d" }}{% endcapture %}
+        {% capture this_month %}{{ post.date | date: "%b" }}{% endcapture %}
+        <span class="date day">{{ this_day }}</span>
+        <span class="date month small text-muted">{{ this_month }}</span>
+        <a href="{{ post.url | relative_url }}">{{ post.title }}</a>
+      </div>
+    </li>
+  {% if forloop.last %}
+  </ul>
+  {% elsif this_year != pre_year %}
+  </ul>
+  <span class="lead">{{pre_year}}</span>
+  <ul class="list-unstyled">
+    {% assign last_day = "" %}
+    {% assign last_month = "" %}
+  {% endif %}
+{% endfor %}
+</div>