Refactor theme mode toggle

- Improve mode switching JS execution priority
- Drop deprecated Web API

_includes/sidebar.html

@@ -52,7 +52,17 @@
   </ul> <!-- ul.nav.flex-column -->
 
   <div class="sidebar-bottom mt-auto d-flex flex-wrap justify-content-center align-items-center">
-    
+
+    {% unless site.theme_mode %}
+      <a id="mode-toggle-wrapper" tabindex="0" onclick="flipMode()">
+        <i class="mode-toggle fas fa-adjust"></i>
+      </a>
+
+      {% if site.data.contact.size > 0 %}
+        <span class="icon-border"></span>
+      {% endif %}
+    {% endunless %}
+
     {% for entry in site.data.contact %}
       {% capture url %}
         {%- if entry.type == 'github' -%}
@@ -71,7 +81,6 @@
 
       {% if url %}
       <a href="{{ url }}" aria-label="{{ entry.type }}"
-        {% unless site.theme_mode %}class="order-{{ forloop.index | plus: 2 }}"{% endunless %}
         {% unless entry.noblank %}target="_blank" rel="noopener"{% endunless %}>
         <i class="{{ entry.icon }}"></i>
       </a>
@@ -79,16 +88,6 @@
 
     {% endfor %}
 
-    {% unless site.theme_mode %}
-      {% if site.data.contact.size > 0 %}
-        <span class="icon-border order-2"></span>
-      {% endif %}
-
-      <span id="mode-toggle-wrapper" class="order-1" tabindex="0">
-        {% include mode-toggle.html %}
-      </span>
-    {% endunless %}
-
   </div> <!-- .sidebar-bottom -->
 
 </div><!-- #sidebar -->