Added sticky sidebar

Signed-off-by: Jim Martens <github@2martens.de>

_assets/css/critical.scss

@@ -45,6 +45,17 @@
 
 $navbarHeight: 58px;
 
+// sticky sidebar
+@include media-breakpoint-up(lg) {
+  #sidebar {
+    position: sticky;
+    top: $navbarHeight + 15px;
+  }
+  #main.submenu #sidebar {
+    top: 2*$navbarHeight + 15px;
+  }
+}
+
 .large {
   font-size: $font-size-lg;
 }

_layouts/default.html

@@ -29,9 +29,11 @@
                 {{ content }}
             </main>
             <div class="col-lg-4">
+                <div id="sidebar">
                     {% include sidebar.html %}
                 </div>
             </div>
+        </div>
         <button id="back-to-top"
                 class="btn btn-primary btn-lg"
                 title="Click to return to the start of the page" data-toggle="tooltip" data-placement="left">