style: Update color variables in CSS and improve scenario prompts in templates

templates/maintenance.html

@@ -15,7 +15,9 @@
     </label>
   </div>
   {% else %}
-  <p class="empty-state">Create a scenario to view maintenance entries.</p>
+  <p class="empty-state">
+    Create a <a href="scenarios">scenario</a> to view maintenance entries.
+  </p>
   {% endif %}
   <div id="maintenance-empty" class="empty-state">
     Choose a scenario to review upcoming or completed maintenance.
@@ -95,7 +97,8 @@
   <p id="maintenance-feedback" class="feedback hidden" role="status"></p>
   {% else %}
   <p class="empty-state">
-    Create a scenario before managing maintenance entries.
+    Create a <a href="scenarios">scenario</a> before managing maintenance
+    entries.
   </p>
   {% endif %}
 </section>