theme: use different style classes for navbar labels

data/theme/gtk-styles.css

@@ -9,8 +9,15 @@
     background-image: none;
 }
 
-.nav-header {
-    font: bold 12;
+/* nav-bar labels */
+.start-header {
+    font: bold 18;
+    color: @theme_selected_bg_color;
+    padding: 12px;
+}
+
+.end-header {
+    font: bold 18;
     padding: 12px;
 }
 
@@ -56,4 +63,4 @@ GcalEventWidget.color-light {
 
 GcalEventWidget.color-light:backdrop {
     color: rgba(0, 0, 0, 0.3);
-}
+}

data/ui/nav_bar.ui

@@ -12,7 +12,7 @@
         <property name="visible">True</property>
         <property name="can_focus">False</property>
         <style>
-          <class name="nav-header"/>
+          <class name="start-header"/>
         </style>
       </object>
       <packing>
@@ -27,7 +27,7 @@
         <property name="halign">end</property>
         <property name="hexpand">True</property>
         <style>
-          <class name="nav-header"/>
+          <class name="end-header"/>
           <class name="dim-label"/>
         </style>
       </object>