diff --git a/src/window.ui b/src/window.ui
index 0998ca6..62b03b4 100644
--- a/src/window.ui
+++ b/src/window.ui
@@ -11,54 +11,69 @@
     <property name="default-height">720</property>
 
       <property name="content">
-        <object class="AdwNavigationSplitView" id="split_view">
-          <property name="sidebar">
-            <object class="AdwNavigationPage">
-              <property name="title" translatable="yes">Sidebar</property>
-              <property name="child">
+        <object class="AdwOverlaySplitView" id="split_view">
+          <property name="sidebar-width-fraction">0.25</property>
+          <property name="sidebar-width-unit">px</property>
+          <property name="max-sidebar-width">200</property>
+          <property name="min-sidebar-width">200</property>
+          <property name="show-sidebar">true</property>
 
-                <object class="AdwToolbarView">
-                  <child type="top">
-                    <object class="AdwHeaderBar">
-                      <property name="show-end-title-buttons">false</property>
-                      <property name="show-title">false</property>
-                      <child type="end">
-                        <object class="GtkMenuButton">
-                          <property name="primary">True</property>
-                          <property name="icon-name">open-menu-symbolic</property>
-                          <property name="tooltip-text" translatable="yes">Main Menu</property>
-                          <property name="menu-model">primary_menu</property>
-                        </object>
-                      </child>
+          <property name="sidebar">
+            <object class="AdwToolbarView">
+              <child type="top">
+                <object class="AdwHeaderBar">
+
+                  <property name="title-widget">
+                    <object class="GtkLabel">
+                      <property name="label" translatable="yes">WorldBuilder</property>
+                      <style>
+                        <class name="heading"/>
+                      </style>
+                    </object>
+                  </property>
+
+                  <property name="show-end-title-buttons">false</property>
+                  <child type="end">
+                    <object class="GtkMenuButton">
+                      <property name="primary">True</property>
+                      <property name="icon-name">open-menu-symbolic</property>
+                      <property name="tooltip-text" translatable="yes">Main Menu</property>
+                      <property name="menu-model">primary_menu</property>
                     </object>
                   </child>
                 </object>
-
-              </property>
+              </child>
             </object>
           </property>
+          
           <property name="content">
-            <object class="AdwNavigationPage">
-              <property name="title" translatable="yes">Worldbuilder</property>
-              <property name="child">
+            <object class="AdwToolbarView">
+              <property name="top-bar-style">flat</property>
+              <child type="top">
+                <object class="AdwHeaderBar">
+                  <property name="show-end-title-buttons">true</property>
+                  <property name="show-title">false</property>
 
-              <object class="AdwToolbarView">
-                <child type="top">
-                  <object class="AdwHeaderBar">
-                    <property name="show-end-title-buttons">true</property>
-                    <property name="show-title">true</property>
-                  </object>
-                </child>
+                  <style>
+                    <class name="preview-headerbar"/>
+                  </style>
 
-                <child>
-                  <object class="GtkGLArea" id="draw_area">
-                    <property name="hexpand">true</property>
-                    <property name="vexpand">true</property>
-                  </object>
-                </child>
-              </object>
-            </property>
+                  <child type="start">
+                    <object class="GtkToggleButton" id="sidebar_toggle_button">
+                      <property name="icon-name">sidebar-show-symbolic</property>
+                      <property name="tooltip-text" translatable="yes">Toggle Sidebar</property>
+                      <property name="active" bind-source="split_view" bind-property="show-sidebar" bind-flags="sync-create | bidirectional">True</property>
+                    </object>
+                  </child>
+                </object>
+              </child>
 
+              <child>
+                <object class="GtkGLArea" id="draw_area">
+                  <property name="hexpand">true</property>
+                  <property name="vexpand">true</property>
+                </object>
+              </child>
             </object>
           </property>
         </object>