client/css: improve mobile styling

client/html/tag_categories.tpl

@@ -1,17 +1,19 @@
 <div class='content-wrapper tag-categories'>
     <form>
         <h1>Tag categories</h1>
-        <table>
-            <thead>
-                <tr>
-                    <th class='name'>Category name</th>
-                    <th class='color'>CSS color</th>
-                    <th class='usages'>Usages</th>
-                </tr>
-            </thead>
-            <tbody>
-            </tbody>
-        </table>
+        <div class="table-wrap">
+            <table>
+                <thead>
+                    <tr>
+                        <th class='name'>Category name</th>
+                        <th class='color'>CSS color</th>
+                        <th class='usages'>Usages</th>
+                    </tr>
+                </thead>
+                <tbody>
+                </tbody>
+            </table>
+        </div>
 
         <% if (ctx.canCreate) { %>
             <p><a href class='add'>Add new category</a></p>

client/html/tags_page.tpl

@@ -1,4 +1,4 @@
-<div class='tag-list'>
+<div class='tag-list table-wrap'>
     <% if (ctx.response.results.length) { %>
         <table>
             <thead>

client/html/top_navigation.tpl

@@ -1,5 +1,9 @@
 <nav id='top-navigation' class='buttons'><!--
     --><ul><!--
+        --><button id="mobile-navigation-toggle"><!--
+            --><span class="site-name"><%- ctx.name %></span><!--
+            --><span class="toggle-icon"><i class="fa fa-bars"></i></span><!--
+        --></button><!--
         --><% for (let item of ctx.items) { %><!--
             --><% if (item.available) { %><!--
                 --><li data-name='<%- item.key %>'><!--