diff --git a/_includes/package-nav.html b/_includes/package-nav.html
index bfab7f0..b42f867 100644
--- a/_includes/package-nav.html
+++ b/_includes/package-nav.html
@@ -1,25 +1,28 @@
 <li><a href="intro.html">Introduction</a></li>
 
-<li class="dropdown-header"><a href="essentials.html">Data science essentials</a></li>
+<li class="dropdown-header"><a href="essentials.html">Understand data</a></li>
 <li><a href="visualize.html">Visualize</a></li>
 <li><a href="transform.html">Transform</a></li>
-<li><a href="relational-data.html">Relational data</a></li>
-<li><a href="tidy.html">Tidy</a></li>
 <li><a href="model.html">Model</a></li>
-<li><a href="import.html">Import</a></li>
 <li><a href="eda.html">Explore</a></li>
 
-<li class="dropdown-header">Communication</li>
+<li class="dropdown-header">Work with your data</li>
+<li><a href="import.html">Import</a></li>
+<li><a href="tidy.html">Tidy</a></li>
+<li><a href="relational-data.html">Relational data</a></li>
+<li><a href="strings.html">Strings</a></li>
+<li><a href="datetimes.html">Dates and times</a></li>
+
+<li class="dropdown-header">Save time with programming</li>
+<li><a href="data-structures.html">Data structures</a></li>
+<li><a href="functions.html">Express yourself with functions</a></li>
+<li><a href="lists.html">Lists and functional programming</a></li>
+
+<li class="dropdown-header">Model data to get deeper insights</li>
+<li><a href="model-vis.html">Models and visualisation</a></li>
+<li><a href="model-assess.html">Model assessment</a></li>
+
+<li class="dropdown-header">Communicate your results</li>
 <li><a href="rmarkdown.html">R Markdown</a></li>
 <li><a href="shiny.html">Shiny</a></li>
 
-<li class="dropdown-header">Programming</li>
-<li><a href="data-structures.html">Data structures</a></li>
-<li><a href="functions.html">Expressing yourself</a></li>
-<li><a href="strings.html">Strings</a></li>
-<li><a href="datetimes.html">Dates and times</a></li>
-<li><a href="lists.html">Lists</a></li>
-
-<li class="dropdown-header">Modelling</li>
-<li><a href="model-vis.html">Models and visualisation</a></li>
-<li><a href="model-assess.html">Model assessment</a></li>
diff --git a/www/highlight.css b/www/highlight.css
index 3246e1a..40a2b84 100644
--- a/www/highlight.css
+++ b/www/highlight.css
@@ -50,10 +50,11 @@ ul .dropdown-header:first-child {
   margin-top: 2px;
 }
 
-.dropdown-header {
+.dropdown-header, .dropdown-header a:link, .dropdown-header a:visited {
   font-weight: bold;
   color: #333;
   margin-top: 8px;
+  text-align: left;
 }
 
 .dropdown-menu .dropdown-header {