diff --git a/build.rs b/build.rs
index 0035e54..47065f3 100644
--- a/build.rs
+++ b/build.rs
@@ -44,6 +44,14 @@ fn main() {
     let gresource_xml = data_dir.join("resources.gresource.xml");
     println!("cargo:rerun-if-changed={}", gresource_xml.display());
 
+    // Watch HTML/CSS so changes trigger a resource rebuild
+    let html_dir = manifest_dir.join("html");
+    if let Ok(entries) = std::fs::read_dir(&html_dir) {
+        for entry in entries.filter_map(|e| e.ok()) {
+            println!("cargo:rerun-if-changed={}", entry.path().display());
+        }
+    }
+
     let gresource_out = out_dir.join("feedthemonkey.gresource");
     let status = Command::new("glib-compile-resources")
         .arg(format!("--sourcedir={}", data_dir.display()))
diff --git a/data/net.jeena.FeedTheMonkey.gschema.xml b/data/net.jeena.FeedTheMonkey.gschema.xml
index e0790c4..16ae75d 100644
--- a/data/net.jeena.FeedTheMonkey.gschema.xml
+++ b/data/net.jeena.FeedTheMonkey.gschema.xml
@@ -21,5 +21,9 @@
       <default>1.0</default>
       <summary>WebView zoom level</summary>
     </key>
+    <key name="content-filters" type="s">
+      <default>''</default>
+      <summary>Content rewrite rules, one per line: domain from to [from to …]</summary>
+    </key>
   </schema>
 </schemalist>
diff --git a/data/resources.gresource.xml b/data/resources.gresource.xml
index e5d363a..ef69e9b 100644
--- a/data/resources.gresource.xml
+++ b/data/resources.gresource.xml
@@ -5,6 +5,7 @@
     <file preprocess="xml-stripblanks">ui/login_dialog.ui</file>
     <file preprocess="xml-stripblanks">ui/article_row.ui</file>
     <file preprocess="xml-stripblanks">ui/shortcuts.ui</file>
+    <file preprocess="xml-stripblanks">ui/preferences_dialog.ui</file>
     <file>html/content.html</file>
     <file>html/content.css</file>
   </gresource>
diff --git a/data/ui/article_row.blp b/data/ui/article_row.blp
index 052b813..ea4c08d 100644
--- a/data/ui/article_row.blp
+++ b/data/ui/article_row.blp
@@ -27,6 +27,7 @@ template $ArticleRow : Gtk.Box {
   }
 
   Label title_label {
+    hexpand: true;
     xalign: 0;
     wrap: true;
     lines: 2;
@@ -34,6 +35,7 @@ template $ArticleRow : Gtk.Box {
   }
 
   Label excerpt_label {
+    hexpand: true;
     xalign: 0;
     ellipsize: end;
     lines: 1;
diff --git a/data/ui/article_row.ui b/data/ui/article_row.ui
index 1218020..e159ff1 100644
--- a/data/ui/article_row.ui
+++ b/data/ui/article_row.ui
@@ -41,6 +41,7 @@ corresponding .blp file and regenerate this file with blueprint-compiler.
     </child>
     <child>
       <object class="GtkLabel" id="title_label">
+        <property name="hexpand">true</property>
         <property name="xalign">0</property>
         <property name="wrap">true</property>
         <property name="lines">2</property>
@@ -49,6 +50,7 @@ corresponding .blp file and regenerate this file with blueprint-compiler.
     </child>
     <child>
       <object class="GtkLabel" id="excerpt_label">
+        <property name="hexpand">true</property>
         <property name="xalign">0</property>
         <property name="ellipsize">3</property>
         <property name="lines">1</property>
diff --git a/data/ui/preferences_dialog.blp b/data/ui/preferences_dialog.blp
new file mode 100644
index 0000000..94fe343
--- /dev/null
+++ b/data/ui/preferences_dialog.blp
@@ -0,0 +1,29 @@
+using Gtk 4.0;
+using Adw 1;
+
+template $PreferencesDialog : Adw.Dialog {
+  title: _("Preferences");
+  content-width: 500;
+  content-height: 400;
+
+  Adw.ToolbarView {
+    [top]
+    Adw.HeaderBar {}
+
+    Adw.PreferencesPage {
+      Adw.PreferencesGroup {
+        title: _("Content Filters");
+        description: _("One rule per line: domain  find  replace  [find  replace …]\n\nExample:\n  www.imycomic.com  -150x150.jpg  .jpg");
+
+        TextView filters_text_view {
+          monospace: true;
+          wrap-mode: word;
+          top-margin: 8;
+          bottom-margin: 8;
+          left-margin: 8;
+          right-margin: 8;
+        }
+      }
+    }
+  }
+}
diff --git a/data/ui/preferences_dialog.ui b/data/ui/preferences_dialog.ui
new file mode 100644
index 0000000..6fefaad
--- /dev/null
+++ b/data/ui/preferences_dialog.ui
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+DO NOT EDIT!
+This file was @generated by blueprint-compiler. Instead, edit the
+corresponding .blp file and regenerate this file with blueprint-compiler.
+-->
+<interface>
+  <requires lib="gtk" version="4.0"/>
+  <template class="PreferencesDialog" parent="AdwDialog">
+    <property name="title" translatable="yes">Preferences</property>
+    <property name="content-width">500</property>
+    <property name="content-height">400</property>
+    <child>
+      <object class="AdwToolbarView">
+        <child type="top">
+          <object class="AdwHeaderBar"></object>
+        </child>
+        <child>
+          <object class="AdwPreferencesPage">
+            <child>
+              <object class="AdwPreferencesGroup">
+                <property name="title" translatable="yes">Content Filters</property>
+                <property name="description" translatable="yes">One rule per line: domain  find  replace  [find  replace …]
+
+Example:
+  www.imycomic.com  -150x150.jpg  .jpg</property>
+                <child>
+                  <object class="GtkTextView" id="filters_text_view">
+                    <property name="monospace">true</property>
+                    <property name="wrap-mode">2</property>
+                    <property name="top-margin">8</property>
+                    <property name="bottom-margin">8</property>
+                    <property name="left-margin">8</property>
+                    <property name="right-margin">8</property>
+                  </object>
+                </child>
+              </object>
+            </child>
+          </object>
+        </child>
+      </object>
+    </child>
+  </template>
+</interface>
\ No newline at end of file
diff --git a/data/ui/shortcuts.blp b/data/ui/shortcuts.blp
index 94c72e8..7d76ec3 100644
--- a/data/ui/shortcuts.blp
+++ b/data/ui/shortcuts.blp
@@ -79,6 +79,11 @@ ShortcutsWindow help_overlay {
         accelerator: "<Control>0";
       }
 
+      ShortcutsShortcut {
+        title: _("Toggle sidebar");
+        accelerator: "F9";
+      }
+
       ShortcutsShortcut {
         title: _("Toggle fullscreen");
         accelerator: "F11";
diff --git a/data/ui/shortcuts.ui b/data/ui/shortcuts.ui
index 5392972..e51f173 100644
--- a/data/ui/shortcuts.ui
+++ b/data/ui/shortcuts.ui
@@ -97,6 +97,12 @@ corresponding .blp file and regenerate this file with blueprint-compiler.
                 <property name="accelerator">&lt;Control&gt;0</property>
               </object>
             </child>
+            <child>
+              <object class="GtkShortcutsShortcut">
+                <property name="title" translatable="yes">Toggle sidebar</property>
+                <property name="accelerator">F9</property>
+              </object>
+            </child>
             <child>
               <object class="GtkShortcutsShortcut">
                 <property name="title" translatable="yes">Toggle fullscreen</property>
diff --git a/data/ui/window.blp b/data/ui/window.blp
index 9ded4f7..6c0192d 100644
--- a/data/ui/window.blp
+++ b/data/ui/window.blp
@@ -7,121 +7,140 @@ template $FeedTheMonkeyWindow : Adw.ApplicationWindow {
   default-height: 600;
 
   Adw.ToastOverlay toast_overlay {
-    Adw.NavigationSplitView split_view {
-      sidebar: Adw.NavigationPage {
-        title: _("FeedTheMonkey");
+    Paned paned {
+      focusable: false;
+      shrink-start-child: false;
+      resize-start-child: false;
 
-        Adw.ToolbarView {
-          [top]
-          Adw.HeaderBar {
-            [start]
-            Stack refresh_stack {
-              StackPage {
-                name: "button";
-                child: Button refresh_button {
-                  icon-name: "view-refresh-symbolic";
-                  tooltip-text: _("Refresh");
-                  action-name: "win.reload";
-                };
-              }
+      start-child: Adw.ToolbarView sidebar_toolbar {
+        top-bar-style: raised;
 
-              StackPage {
-                name: "spinner";
-                child: Adw.Spinner {};
-              }
+        [top]
+        Adw.HeaderBar {
+          show-start-title-buttons: false;
+          show-end-title-buttons: false;
+
+          title-widget: Box {};
+
+          [start]
+          Stack refresh_stack {
+            StackPage {
+              name: "button";
+              child: Button refresh_button {
+                icon-name: "view-refresh-symbolic";
+                tooltip-text: _("Refresh");
+                action-name: "win.reload";
+              };
             }
-
-            [end]
-            MenuButton menu_button {
-              icon-name: "open-menu-symbolic";
-              primary: true;
-              menu-model: primary_menu;
+            StackPage {
+              name: "spinner";
+              child: Spinner {
+                spinning: true;
+                width-request: 16;
+                height-request: 16;
+              };
             }
           }
 
-          Stack sidebar_content {
-            StackPage {
-              name: "placeholder";
-              child: Adw.StatusPage {
-                icon-name: "rss-symbolic";
-                title: _("FeedTheMonkey");
-                description: _("Log in to load your articles");
-              };
-            }
+          [end]
+          MenuButton menu_button {
+            icon-name: "open-menu-symbolic";
+            primary: true;
+            menu-model: primary_menu;
+          }
+        }
 
-            StackPage {
-              name: "loading";
-              child: Adw.StatusPage {
-                paintable: Adw.SpinnerPaintable {};
-                title: _("Loading…");
-              };
-            }
+        Stack sidebar_content {
+          styles ["sidebar-content"]
 
-            StackPage {
-              name: "empty";
-              child: Adw.StatusPage {
-                icon-name: "rss-symbolic";
-                title: _("No Unread Articles");
-              };
-            }
+          StackPage {
+            name: "placeholder";
+            child: Adw.StatusPage {
+              icon-name: "rss-symbolic";
+              title: _("FeedTheMonkey");
+              description: _("Log in to load your articles");
+            };
+          }
 
-            StackPage {
-              name: "error";
-              child: Adw.StatusPage error_status {
-                icon-name: "network-error-symbolic";
-                title: _("Could Not Load Articles");
+          StackPage {
+            name: "loading";
+            child: Adw.StatusPage {
+              title: _("Loading…");
+            };
+          }
 
-                Button {
-                  label: _("Try Again");
-                  halign: center;
-                  action-name: "win.reload";
-                  styles ["pill", "suggested-action"]
-                }
-              };
-            }
+          StackPage {
+            name: "empty";
+            child: Adw.StatusPage {
+              icon-name: "rss-symbolic";
+              title: _("No Unread Articles");
+            };
+          }
 
-            StackPage {
-              name: "list";
-              child: ScrolledWindow {
-                hscrollbar-policy: never;
-                ListView article_list_view {
-                  single-click-activate: true;
-                }
-              };
-            }
+          StackPage {
+            name: "error";
+            child: Adw.StatusPage error_status {
+              icon-name: "network-error-symbolic";
+              title: _("Could Not Load Articles");
+
+              Button {
+                label: _("Try Again");
+                halign: center;
+                action-name: "win.reload";
+                styles ["pill", "suggested-action"]
+              }
+            };
+          }
+
+          StackPage {
+            name: "list";
+            child: ScrolledWindow {
+              hscrollbar-policy: never;
+              ListView article_list_view {
+                single-click-activate: false;
+                show-separators: true;
+              }
+            };
           }
         }
       };
 
-      content: Adw.NavigationPage content_page {
-        title: _("FeedTheMonkey");
+      end-child: Adw.ToolbarView {
+        top-bar-style: raised;
 
-        Adw.ToolbarView {
-          top-bar-style: raised;
-
-          [top]
-          Adw.HeaderBar {
-            [end]
-            MenuButton article_menu_button {
-              icon-name: "view-more-symbolic";
-              menu-model: article_menu;
-              visible: false;
-            }
+        [top]
+        Adw.HeaderBar {
+          [start]
+          Button toggle_sidebar_button {
+            icon-name: "sidebar-show-symbolic";
+            tooltip-text: _("Toggle Sidebar");
+            action-name: "win.toggle-sidebar";
           }
 
-          Stack content_stack {
-            StackPage {
-              name: "empty";
-              child: Adw.StatusPage {
-                icon-name: "document-open-symbolic";
-                title: _("No Article Selected");
-              };
-            }
+          title-widget: Adw.WindowTitle {
+            title: _("FeedTheMonkey");
+          };
 
-            StackPage {
-              name: "webview";
-              child: WebKit.WebView web_view {};
-            }
+          [end]
+          MenuButton article_menu_button {
+            icon-name: "view-more-symbolic";
+            menu-model: article_menu;
+            visible: false;
+          }
+        }
+
+        Stack content_stack {
+          StackPage {
+            name: "empty";
+            child: Adw.StatusPage {
+              icon-name: "document-open-symbolic";
+              title: _("No Article Selected");
+            };
+          }
+
+          StackPage {
+            name: "webview";
+            child: WebKit.WebView web_view {};
           }
         }
       };
@@ -137,6 +156,13 @@ menu primary_menu {
     }
   }
 
+  section {
+    item {
+      label: _("Preferences");
+      action: "win.preferences";
+    }
+  }
+
   section {
     item {
       label: _("Keyboard Shortcuts");
diff --git a/data/ui/window.ui b/data/ui/window.ui
index 5ee9da1..e9cd9cc 100644
--- a/data/ui/window.ui
+++ b/data/ui/window.ui
@@ -12,166 +12,182 @@ corresponding .blp file and regenerate this file with blueprint-compiler.
     <child>
       <object class="AdwToastOverlay" id="toast_overlay">
         <child>
-          <object class="AdwNavigationSplitView" id="split_view">
-            <property name="sidebar">
-              <object class="AdwNavigationPage">
-                <property name="title" translatable="yes">FeedTheMonkey</property>
-                <child>
-                  <object class="AdwToolbarView">
-                    <child type="top">
-                      <object class="AdwHeaderBar">
-                        <child type="start">
-                          <object class="GtkStack" id="refresh_stack">
-                            <child>
-                              <object class="GtkStackPage">
-                                <property name="name">button</property>
-                                <property name="child">
-                                  <object class="GtkButton" id="refresh_button">
-                                    <property name="icon-name">view-refresh-symbolic</property>
-                                    <property name="tooltip-text" translatable="yes">Refresh</property>
-                                    <property name="action-name">win.reload</property>
-                                  </object>
-                                </property>
+          <object class="GtkPaned" id="paned">
+            <property name="focusable">false</property>
+            <property name="shrink-start-child">false</property>
+            <property name="resize-start-child">false</property>
+            <property name="start-child">
+              <object class="AdwToolbarView" id="sidebar_toolbar">
+                <property name="top-bar-style">1</property>
+                <child type="top">
+                  <object class="AdwHeaderBar">
+                    <property name="show-start-title-buttons">false</property>
+                    <property name="show-end-title-buttons">false</property>
+                    <property name="title-widget">
+                      <object class="GtkBox"></object>
+                    </property>
+                    <child type="start">
+                      <object class="GtkStack" id="refresh_stack">
+                        <child>
+                          <object class="GtkStackPage">
+                            <property name="name">button</property>
+                            <property name="child">
+                              <object class="GtkButton" id="refresh_button">
+                                <property name="icon-name">view-refresh-symbolic</property>
+                                <property name="tooltip-text" translatable="yes">Refresh</property>
+                                <property name="action-name">win.reload</property>
                               </object>
-                            </child>
-                            <child>
-                              <object class="GtkStackPage">
-                                <property name="name">spinner</property>
-                                <property name="child">
-                                  <object class="AdwSpinner"></object>
-                                </property>
-                              </object>
-                            </child>
+                            </property>
                           </object>
                         </child>
-                        <child type="end">
-                          <object class="GtkMenuButton" id="menu_button">
-                            <property name="icon-name">open-menu-symbolic</property>
-                            <property name="primary">true</property>
-                            <property name="menu-model">primary_menu</property>
+                        <child>
+                          <object class="GtkStackPage">
+                            <property name="name">spinner</property>
+                            <property name="child">
+                              <object class="GtkSpinner">
+                                <property name="spinning">true</property>
+                                <property name="width-request">16</property>
+                                <property name="height-request">16</property>
+                              </object>
+                            </property>
                           </object>
                         </child>
                       </object>
                     </child>
+                    <child type="end">
+                      <object class="GtkMenuButton" id="menu_button">
+                        <property name="icon-name">open-menu-symbolic</property>
+                        <property name="primary">true</property>
+                        <property name="menu-model">primary_menu</property>
+                      </object>
+                    </child>
+                  </object>
+                </child>
+                <child>
+                  <object class="GtkStack" id="sidebar_content">
+                    <style>
+                      <class name="sidebar-content"/>
+                    </style>
                     <child>
-                      <object class="GtkStack" id="sidebar_content">
-                        <child>
-                          <object class="GtkStackPage">
-                            <property name="name">placeholder</property>
-                            <property name="child">
-                              <object class="AdwStatusPage">
-                                <property name="icon-name">rss-symbolic</property>
-                                <property name="title" translatable="yes">FeedTheMonkey</property>
-                                <property name="description" translatable="yes">Log in to load your articles</property>
-                              </object>
-                            </property>
+                      <object class="GtkStackPage">
+                        <property name="name">placeholder</property>
+                        <property name="child">
+                          <object class="AdwStatusPage">
+                            <property name="icon-name">rss-symbolic</property>
+                            <property name="title" translatable="yes">FeedTheMonkey</property>
+                            <property name="description" translatable="yes">Log in to load your articles</property>
                           </object>
-                        </child>
-                        <child>
-                          <object class="GtkStackPage">
-                            <property name="name">loading</property>
-                            <property name="child">
-                              <object class="AdwStatusPage">
-                                <property name="paintable">
-                                  <object class="AdwSpinnerPaintable"></object>
-                                </property>
-                                <property name="title" translatable="yes">Loading…</property>
-                              </object>
-                            </property>
+                        </property>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkStackPage">
+                        <property name="name">loading</property>
+                        <property name="child">
+                          <object class="AdwStatusPage">
+                            <property name="title" translatable="yes">Loading…</property>
                           </object>
-                        </child>
-                        <child>
-                          <object class="GtkStackPage">
-                            <property name="name">empty</property>
-                            <property name="child">
-                              <object class="AdwStatusPage">
-                                <property name="icon-name">rss-symbolic</property>
-                                <property name="title" translatable="yes">No Unread Articles</property>
-                              </object>
-                            </property>
+                        </property>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkStackPage">
+                        <property name="name">empty</property>
+                        <property name="child">
+                          <object class="AdwStatusPage">
+                            <property name="icon-name">rss-symbolic</property>
+                            <property name="title" translatable="yes">No Unread Articles</property>
                           </object>
-                        </child>
-                        <child>
-                          <object class="GtkStackPage">
-                            <property name="name">error</property>
-                            <property name="child">
-                              <object class="AdwStatusPage" id="error_status">
-                                <property name="icon-name">network-error-symbolic</property>
-                                <property name="title" translatable="yes">Could Not Load Articles</property>
-                                <child>
-                                  <object class="GtkButton">
-                                    <property name="label" translatable="yes">Try Again</property>
-                                    <property name="halign">3</property>
-                                    <property name="action-name">win.reload</property>
-                                    <style>
-                                      <class name="pill"/>
-                                      <class name="suggested-action"/>
-                                    </style>
-                                  </object>
-                                </child>
+                        </property>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkStackPage">
+                        <property name="name">error</property>
+                        <property name="child">
+                          <object class="AdwStatusPage" id="error_status">
+                            <property name="icon-name">network-error-symbolic</property>
+                            <property name="title" translatable="yes">Could Not Load Articles</property>
+                            <child>
+                              <object class="GtkButton">
+                                <property name="label" translatable="yes">Try Again</property>
+                                <property name="halign">3</property>
+                                <property name="action-name">win.reload</property>
+                                <style>
+                                  <class name="pill"/>
+                                  <class name="suggested-action"/>
+                                </style>
                               </object>
-                            </property>
+                            </child>
                           </object>
-                        </child>
-                        <child>
-                          <object class="GtkStackPage">
-                            <property name="name">list</property>
-                            <property name="child">
-                              <object class="GtkScrolledWindow">
-                                <property name="hscrollbar-policy">2</property>
-                                <child>
-                                  <object class="GtkListView" id="article_list_view">
-                                    <property name="single-click-activate">true</property>
-                                  </object>
-                                </child>
+                        </property>
+                      </object>
+                    </child>
+                    <child>
+                      <object class="GtkStackPage">
+                        <property name="name">list</property>
+                        <property name="child">
+                          <object class="GtkScrolledWindow">
+                            <property name="hscrollbar-policy">2</property>
+                            <child>
+                              <object class="GtkListView" id="article_list_view">
+                                <property name="single-click-activate">false</property>
+                                <property name="show-separators">true</property>
                               </object>
-                            </property>
+                            </child>
                           </object>
-                        </child>
+                        </property>
                       </object>
                     </child>
                   </object>
                 </child>
               </object>
             </property>
-            <property name="content">
-              <object class="AdwNavigationPage" id="content_page">
-                <property name="title" translatable="yes">FeedTheMonkey</property>
+            <property name="end-child">
+              <object class="AdwToolbarView">
+                <property name="top-bar-style">1</property>
+                <child type="top">
+                  <object class="AdwHeaderBar">
+                    <child type="start">
+                      <object class="GtkButton" id="toggle_sidebar_button">
+                        <property name="icon-name">sidebar-show-symbolic</property>
+                        <property name="tooltip-text" translatable="yes">Toggle Sidebar</property>
+                        <property name="action-name">win.toggle-sidebar</property>
+                      </object>
+                    </child>
+                    <property name="title-widget">
+                      <object class="AdwWindowTitle">
+                        <property name="title" translatable="yes">FeedTheMonkey</property>
+                      </object>
+                    </property>
+                    <child type="end">
+                      <object class="GtkMenuButton" id="article_menu_button">
+                        <property name="icon-name">view-more-symbolic</property>
+                        <property name="menu-model">article_menu</property>
+                        <property name="visible">false</property>
+                      </object>
+                    </child>
+                  </object>
+                </child>
                 <child>
-                  <object class="AdwToolbarView">
-                    <property name="top-bar-style">1</property>
-                    <child type="top">
-                      <object class="AdwHeaderBar">
-                        <child type="end">
-                          <object class="GtkMenuButton" id="article_menu_button">
-                            <property name="icon-name">view-more-symbolic</property>
-                            <property name="menu-model">article_menu</property>
-                            <property name="visible">false</property>
+                  <object class="GtkStack" id="content_stack">
+                    <child>
+                      <object class="GtkStackPage">
+                        <property name="name">empty</property>
+                        <property name="child">
+                          <object class="AdwStatusPage">
+                            <property name="icon-name">document-open-symbolic</property>
+                            <property name="title" translatable="yes">No Article Selected</property>
                           </object>
-                        </child>
+                        </property>
                       </object>
                     </child>
                     <child>
-                      <object class="GtkStack" id="content_stack">
-                        <child>
-                          <object class="GtkStackPage">
-                            <property name="name">empty</property>
-                            <property name="child">
-                              <object class="AdwStatusPage">
-                                <property name="icon-name">document-open-symbolic</property>
-                                <property name="title" translatable="yes">No Article Selected</property>
-                              </object>
-                            </property>
-                          </object>
-                        </child>
-                        <child>
-                          <object class="GtkStackPage">
-                            <property name="name">webview</property>
-                            <property name="child">
-                              <object class="WebKitWebView" id="web_view"></object>
-                            </property>
-                          </object>
-                        </child>
+                      <object class="GtkStackPage">
+                        <property name="name">webview</property>
+                        <property name="child">
+                          <object class="WebKitWebView" id="web_view"></object>
+                        </property>
                       </object>
                     </child>
                   </object>
@@ -190,6 +206,12 @@ corresponding .blp file and regenerate this file with blueprint-compiler.
         <attribute name="action">win.logout</attribute>
       </item>
     </section>
+    <section>
+      <item>
+        <attribute name="label" translatable="yes">Preferences</attribute>
+        <attribute name="action">win.preferences</attribute>
+      </item>
+    </section>
     <section>
       <item>
         <attribute name="label" translatable="yes">Keyboard Shortcuts</attribute>
diff --git a/html/content.css b/html/content.css
index c3f979b..4fc396b 100644
--- a/html/content.css
+++ b/html/content.css
@@ -1,101 +1,131 @@
-* {
-  box-sizing: border-box;
+/* CSS custom properties are set from Rust via AdwStyleManager.
+   The :root defaults below act as a light-mode fallback only. */
+
+:root {
+  --bg:          #ffffff;
+  --fg:          #1a1a1a;
+  --fg-dim:      rgba(0,0,0,0.55);
+  --border:      rgba(0,0,0,0.12);
+  --header-bg:   #f6f5f4;
+  --link:        #1c71d8;
+  --code-bg:     rgba(0,0,0,0.06);
+  --blockquote-border: rgba(0,0,0,0.2);
+  --font:        sans-serif;
+  --font-size:   15px;
 }
 
-body {
-  font-family: sans-serif;
+:root[data-dark="1"] {
+  --bg:          #1e1e1e;
+  --fg:          rgba(255,255,255,0.87);
+  --fg-dim:      rgba(255,255,255,0.5);
+  --border:      rgba(255,255,255,0.12);
+  --header-bg:   #242424;
+  --link:        #78aeed;
+  --code-bg:     rgba(255,255,255,0.06);
+  --blockquote-border: rgba(255,255,255,0.2);
+}
+
+* { box-sizing: border-box; }
+
+html, body {
   margin: 0;
   padding: 0;
-  line-height: 1.6;
-  color: #222;
-  background: #fff;
+  background: var(--bg);
+  color: var(--fg);
+  font-family: var(--font);
+  font-size: var(--font-size);
+  word-wrap: break-word;
 }
 
-@media (prefers-color-scheme: dark) {
-  body {
-    color: #ddd;
-    background: #1e1e1e;
-  }
-  a {
-    color: #78aeed;
-  }
-  img {
-    opacity: 0.85;
-  }
+a {
+  color: var(--link);
+  text-decoration: none;
 }
 
-#header {
+article a {
+  text-decoration: underline;
+}
+
+header {
   padding: 1.5em 2em 1em;
-  border-bottom: 1px solid rgba(0,0,0,0.1);
-  margin-bottom: 1em;
+  background: var(--header-bg);
+  border-bottom: 1px solid var(--border);
 }
 
-@media (prefers-color-scheme: dark) {
-  #header {
-    border-bottom-color: rgba(255,255,255,0.1);
-  }
+header > .inner,
+article {
+  max-width: 720px;
+  margin-left: auto;
+  margin-right: auto;
 }
 
-#feed-title {
-  font-size: 0.8em;
-  opacity: 0.6;
-  margin-bottom: 0.25em;
-  text-transform: uppercase;
-  letter-spacing: 0.05em;
+header > .inner {
+  padding: 0 2em;
 }
 
-#title {
-  font-size: 1.5em;
-  margin: 0 0 0.5em;
+header h1 {
+  font-size: 1.3em;
+  margin: 0.2em 0 0.4em;
+  padding: 0;
   line-height: 1.3;
 }
 
-#meta {
-  font-size: 0.85em;
-  opacity: 0.6;
-  margin-bottom: 0.5em;
+header h1 a {
+  color: var(--fg);
 }
 
-#meta span + span::before {
-  content: ' · ';
-}
-
-#link {
+header p {
+  color: var(--fg-dim);
+  margin: 0;
+  padding: 0;
   font-size: 0.85em;
 }
 
-#content {
-  padding: 0 2em 2em;
-  max-width: 800px;
+article {
+  line-height: 1.6;
+  padding: 1.5em 2em 2em;
 }
 
-#content img {
+img {
   max-width: 100%;
   height: auto;
 }
 
-#content pre {
-  overflow-x: auto;
-  background: rgba(0,0,0,0.05);
+div > a:only-child img,
+figure > a:only-child img,
+p > a:only-child img,
+figure > img:only-child,
+div > img:only-child,
+p > img:only-child {
+  display: block;
+  margin: 1em auto;
+  float: none !important;
+}
+
+pre {
+  overflow: auto;
+  background: var(--code-bg);
   padding: 1em;
-  border-radius: 4px;
+  border-radius: 6px;
+  font-size: 0.9em;
 }
 
-@media (prefers-color-scheme: dark) {
-  #content pre {
-    background: rgba(255,255,255,0.05);
-  }
+code {
+  background: var(--code-bg);
+  padding: 0.15em 0.35em;
+  border-radius: 3px;
+  font-size: 0.9em;
 }
 
-#content blockquote {
-  border-left: 3px solid rgba(0,0,0,0.2);
+pre code {
+  background: none;
+  padding: 0;
+}
+
+blockquote {
+  border-left: 3px solid var(--blockquote-border);
   margin-left: 0;
   padding-left: 1em;
-  opacity: 0.8;
-}
-
-@media (prefers-color-scheme: dark) {
-  #content blockquote {
-    border-left-color: rgba(255,255,255,0.2);
-  }
+  color: var(--fg-dim);
+  font-style: italic;
 }
diff --git a/html/content.html b/html/content.html
index f817038..82610c9 100644
--- a/html/content.html
+++ b/html/content.html
@@ -2,35 +2,47 @@
 <html>
 <head>
   <meta charset="UTF-8">
+  <meta name="color-scheme" content="light dark">
   <title>FeedTheMonkey</title>
-  <link rel="stylesheet" href="content.css">
+  <style>/*INJECT_CSS*/</style>
 </head>
 <body>
-  <div id="header">
-    <div id="feed-title"></div>
-    <h1 id="title"></h1>
-    <div id="meta">
-      <span id="author"></span>
-      <span id="date"></span>
+  <header>
+    <div class="inner">
+      <p><span id="feed_title"></span> <span id="author"></span></p>
+      <h1><a id="title" href=""></a></h1>
+      <p><time id="date"></time></p>
     </div>
-    <a id="link" href="#" onclick="window.location='feedthemonkey:open'; return false;">Open in Browser</a>
-  </div>
-  <div id="content"></div>
+  </header>
+  <article id="article"></article>
 
   <script>
     function setArticle(article) {
-      document.getElementById('feed-title').textContent = article.feed_title || '';
-      document.getElementById('title').textContent = article.title || '';
-      document.getElementById('author').textContent = article.author || '';
-      document.getElementById('content').innerHTML = article.content || '';
-
-      var ts = article.updated;
-      if (ts) {
-        document.getElementById('date').textContent = new Date(ts * 1000).toLocaleDateString();
-      }
-
       window.scrollTo(0, 0);
-      window._article = article;
+      document.getElementById('date').textContent = '';
+      document.getElementById('title').textContent = '';
+      document.getElementById('title').href = '';
+      document.getElementById('feed_title').textContent = '';
+      document.getElementById('author').textContent = '';
+      document.getElementById('article').innerHTML = '';
+      if (!article) return;
+      document.getElementById('date').textContent =
+        new Date(parseInt(article.updated, 10) * 1000).toLocaleDateString();
+      document.getElementById('title').textContent = article.title || '';
+      document.getElementById('title').href = article.link || '';
+      document.getElementById('feed_title').textContent = article.feed_title || '';
+      if (article.author && article.author.length > 0)
+        document.getElementById('author').textContent = '\u2013 ' + article.author;
+      document.getElementById('article').innerHTML = article.content || '';
+    }
+
+    function setDark(isDark) {
+      document.documentElement.setAttribute('data-dark', isDark ? '1' : '0');
+    }
+
+    function setFont(family, sizePx) {
+      document.documentElement.style.setProperty('--font', family);
+      document.documentElement.style.setProperty('--font-size', sizePx + 'px');
     }
 
     function checkKey(e) {
diff --git a/src/app.rs b/src/app.rs
index b484a01..9581eb5 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -51,6 +51,33 @@ mod imp {
                 .expect("failed to load GResource");
             gio::resources_register(&resource);
 
+            // Apply application-level CSS tweaks
+            let css = gtk4::CssProvider::new();
+            css.load_from_string(
+                "paned > :first-child .top-bar headerbar {
+                    background-color: @headerbar_bg_color;
+                    box-shadow: none;
+                }
+                paned > :first-child > toolbarview > .content {
+                    padding-top: 0;
+                    margin-top: 0;
+                }
+                .sidebar-content row:not(:selected) {
+                    background-color: alpha(@window_fg_color, 0.07);
+                }
+                .sidebar-content row:not(:selected):hover {
+                    background-color: alpha(@window_fg_color, 0.14);
+                }
+                .sidebar-content row:selected {
+                    background-color: alpha(@window_fg_color, 0.22);
+                }"
+            );
+            gtk4::style_context_add_provider_for_display(
+                &gtk4::gdk::Display::default().unwrap(),
+                &css,
+                gtk4::STYLE_PROVIDER_PRIORITY_APPLICATION,
+            );
+
             let window = FeedTheMonkeyWindow::new(app.upcast_ref());
 
             // Shortcuts overlay
@@ -74,7 +101,7 @@ mod imp {
                         .version("3.0.0")
                         .copyright("© Jeena Paradies")
                         .license_type(gtk4::License::Gpl30)
-                        .website("https://github.com/jeena/FeedTheMonkey")
+                        .website("https://git.jeena.net/jeena/FeedTheMonkey")
                         .developer_name("Jeena Paradies")
                         .build();
                     dialog.present(win.as_ref().map(|w| w.upcast_ref::<gtk4::Widget>()));
@@ -116,10 +143,8 @@ fn setup_shortcuts(window: &FeedTheMonkeyWindow) {
         controller.add_shortcut(shortcut);
     };
 
-    add(&controller, Key::j,      ModifierType::empty(),       "win.next-article");
-    add(&controller, Key::Right,  ModifierType::empty(),       "win.next-article");
-    add(&controller, Key::k,      ModifierType::empty(),       "win.prev-article");
-    add(&controller, Key::Left,   ModifierType::empty(),       "win.prev-article");
+    // j/k/Left/Right are handled by a capture-phase key controller in window.rs
+    // so they work regardless of which widget has focus.
     add(&controller, Key::r,      ModifierType::empty(),       "win.reload");
     add(&controller, Key::u,      ModifierType::empty(),       "win.mark-unread");
     add(&controller, Key::Return, ModifierType::empty(),       "win.open-in-browser");
@@ -128,6 +153,7 @@ fn setup_shortcuts(window: &FeedTheMonkeyWindow) {
     add(&controller, Key::equal,  ModifierType::CONTROL_MASK,  "win.zoom-in");
     add(&controller, Key::minus,  ModifierType::CONTROL_MASK,  "win.zoom-out");
     add(&controller, Key::_0,     ModifierType::CONTROL_MASK,  "win.zoom-reset");
+    add(&controller, Key::F9,     ModifierType::empty(),       "win.toggle-sidebar");
     add(&controller, Key::F11,    ModifierType::empty(),       "win.toggle-fullscreen");
     add(&controller, Key::w,      ModifierType::CONTROL_MASK,  "window.close");
     add(&controller, Key::q,      ModifierType::CONTROL_MASK,  "app.quit");
diff --git a/src/filters.rs b/src/filters.rs
new file mode 100644
index 0000000..b41a175
--- /dev/null
+++ b/src/filters.rs
@@ -0,0 +1,68 @@
+/// Content rewrite rules stored in GSettings key "content-filters".
+///
+/// Format — one rule per line, tokens separated by spaces:
+///
+///   domain  from  to  [from  to  …]
+///
+/// Examples:
+///
+///   www.imycomic.com  -150x150.jpg  .jpg
+///   www.stuttmann-karikaturen.de  /thumbs/  /
+///   existentialcomics.com  src="//static  src="https://static
+///
+/// The domain is matched as a substring of the article's GUID and link URL.
+/// Blank lines and lines starting with # are ignored.
+
+use gtk4::gio;
+use gtk4::prelude::SettingsExt;
+
+pub struct Rule {
+    pub pattern: String,
+    pub replacements: Vec<(String, String)>,
+}
+
+/// Parse the multi-line text from the GSettings key into rules.
+pub fn parse(text: &str) -> Vec<Rule> {
+    let mut rules = Vec::new();
+    for line in text.lines() {
+        let line = line.trim();
+        if line.is_empty() || line.starts_with('#') {
+            continue;
+        }
+        let tokens: Vec<&str> = line.splitn(usize::MAX, ' ')
+            .map(str::trim)
+            .filter(|t| !t.is_empty())
+            .collect();
+        if tokens.len() < 3 || tokens.len() % 2 == 0 {
+            // Need: domain + at least one from/to pair (odd total ≥ 3)
+            eprintln!("filters: skipping malformed line: {line}");
+            continue;
+        }
+        let pattern = tokens[0].to_string();
+        let replacements = tokens[1..]
+            .chunks(2)
+            .map(|c| (c[0].to_string(), c[1].to_string()))
+            .collect();
+        rules.push(Rule { pattern, replacements });
+    }
+    rules
+}
+
+/// Load rules from GSettings.
+pub fn load_rules() -> Vec<Rule> {
+    let settings = gio::Settings::new("net.jeena.FeedTheMonkey");
+    parse(&settings.string("content-filters"))
+}
+
+/// Apply all matching rules to `content`.
+pub fn apply(rules: &[Rule], guid: &str, link: &str, content: &str) -> String {
+    let mut out = content.to_string();
+    for rule in rules {
+        if guid.contains(&rule.pattern) || link.contains(&rule.pattern) {
+            for (from, to) in &rule.replacements {
+                out = out.replace(from.as_str(), to.as_str());
+            }
+        }
+    }
+    out
+}
diff --git a/src/preferences_dialog.rs b/src/preferences_dialog.rs
new file mode 100644
index 0000000..f20494a
--- /dev/null
+++ b/src/preferences_dialog.rs
@@ -0,0 +1,75 @@
+use gtk4::prelude::*;
+use gtk4::subclass::prelude::*;
+use gtk4::{gio, glib};
+
+glib::wrapper! {
+    pub struct PreferencesDialog(ObjectSubclass<imp::PreferencesDialog>)
+        @extends libadwaita::Dialog, gtk4::Widget,
+        @implements gtk4::Accessible, gtk4::Buildable, gtk4::ConstraintTarget;
+}
+
+impl PreferencesDialog {
+    pub fn new() -> Self {
+        glib::Object::builder().build()
+    }
+}
+
+pub mod imp {
+    use super::*;
+    use gtk4::CompositeTemplate;
+    use libadwaita::subclass::prelude::*;
+
+    #[derive(CompositeTemplate, Default)]
+    #[template(resource = "/net/jeena/FeedTheMonkey/ui/preferences_dialog.ui")]
+    pub struct PreferencesDialog {
+        #[template_child]
+        pub filters_text_view: TemplateChild<gtk4::TextView>,
+    }
+
+    #[glib::object_subclass]
+    impl ObjectSubclass for PreferencesDialog {
+        const NAME: &'static str = "PreferencesDialog";
+        type Type = super::PreferencesDialog;
+        type ParentType = libadwaita::Dialog;
+
+        fn class_init(klass: &mut Self::Class) {
+            klass.bind_template();
+        }
+
+        fn instance_init(obj: &glib::subclass::InitializingObject<Self>) {
+            obj.init_template();
+        }
+    }
+
+    impl ObjectImpl for PreferencesDialog {
+        fn constructed(&self) {
+            self.parent_constructed();
+            self.load();
+            // Save on every text change
+            let obj_weak = self.obj().downgrade();
+            self.filters_text_view.buffer().connect_changed(move |_| {
+                if let Some(obj) = obj_weak.upgrade() {
+                    obj.imp().save();
+                }
+            });
+        }
+    }
+
+    impl PreferencesDialog {
+        fn load(&self) {
+            let settings = gio::Settings::new("net.jeena.FeedTheMonkey");
+            let text = settings.string("content-filters");
+            self.filters_text_view.buffer().set_text(&text);
+        }
+
+        fn save(&self) {
+            let buf = self.filters_text_view.buffer();
+            let text = buf.text(&buf.start_iter(), &buf.end_iter(), false);
+            let settings = gio::Settings::new("net.jeena.FeedTheMonkey");
+            settings.set_string("content-filters", &text).ok();
+        }
+    }
+
+    impl WidgetImpl for PreferencesDialog {}
+    impl AdwDialogImpl for PreferencesDialog {}
+}