diff --git a/crates/ui-egui/src/options.rs b/crates/ui-egui/src/options.rs
index f9661b372..b2a22a60d 100644
--- a/crates/ui-egui/src/options.rs
+++ b/crates/ui-egui/src/options.rs
@@ -854,486 +854,4 @@ fn numeral_picker(app: &mut WordApp, ui: &mut Ui) {
 }
 
 #[cfg(test)]
-mod tests {
-    use egui_kittest::kittest::{NodeT, Queryable};
-    use serde_json::json;
-    use wordcraft_geom::Unit;
-
-    use super::{decimal, length, parse_length, unit};
-
-    use crate::theme::Appearance;
-    use crate::{Services, UiState, WordApp};
-
-    #[test]
-    fn unknown_settings_keys_load_in_linear_time() {
-        let mut map = serde_json::Map::new();
-        for i in 0..20_000 {
-            map.insert(format!("unknownKey{i}"), json!(i));
-        }
-        map.insert("miniToolbar".into(), json!(false));
-        let bytes = serde_json::to_vec(&serde_json::Value::Object(map)).unwrap();
-        let state = UiState::from_json(&bytes).unwrap();
-        assert!(!state.mini_toolbar);
-    }
-
-    fn app() -> WordApp {
-        WordApp::new(wordcraft_engine::Session::new(wordcraft_doc::Document::new()), Services::default())
-    }
-
-    fn nav_harness(language: &str, percent: u16) -> egui_kittest::Harness<'static, WordApp> {
-        let mut a = app();
-        a.run("ui.language", json!({"value": language})).unwrap();
-        a.run("ui.interfaceSize", json!({"percent": percent})).unwrap();
-        a.run("file.options", json!({"pane": "general"})).unwrap();
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).with_pixels_per_point(2.0).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(4);
-        h
-    }
-
-    /// File › Options must not offer a way around the protected document's author check.
-    #[test]
-    fn user_name_field_disables_when_protection_starts() {
-        let mut h = nav_harness("en", 100);
-        let user_name = || egui_kittest::kittest::By::new().role(egui::accesskit::Role::TextInput).value("WordCraft User");
-        assert!(!h.get(user_name()).accesskit_node().is_disabled());
-        h.state_mut().run("review.restrict", json!({"mode": "readOnly"})).unwrap();
-        h.run_steps(4);
-        assert!(h.get(user_name()).accesskit_node().is_disabled());
-    }
-
-    /// #1266: check the actual painted text and renderer clip, including the bold selected
-    /// label. AccessKit must still expose the full name and the row must keep its fixed size.
-    #[test]
-    fn options_nav_labels_stay_inside_their_rows() {
-        if !crate::i18n::catalogs_embedded() {
-            return;
-        }
-        for language in ["en", "ru"] {
-            for percent in [100, 125, 150] {
-                let mut h = nav_harness(language, percent);
-                // An interface size is absolute (#822): `percent` points per 100 screen pixels,
-                // whatever the display's own scale (2.0 here).
-                assert_eq!(h.ctx.pixels_per_point(), f32::from(percent) / 100.0);
-                for selected in ["general", "accessibility"] {
-                    h.state_mut().run("file.options", json!({"pane": selected})).unwrap();
-                    h.run_steps(4);
-                    for id in wordcraft_engine::cmd::options::PANES {
-                        let label = crate::i18n::tr(crate::i18n::Lang::from_pref(language), super::pane_label(id));
-                        let node =
-                            h.query_all_by_label(label).find(|n| n.accesskit_node().toggled().is_some()).expect("pane has its full accessible name");
-                        assert_eq!(
-                            node.accesskit_node().toggled(),
-                            Some(if id == selected { egui::accesskit::Toggled::True } else { egui::accesskit::Toggled::False })
-                        );
-                        let row = node.rect();
-                        assert_eq!(row.size(), egui::vec2(170.0, 30.0));
-                        let (clip, text) = h
-                            .output()
-                            .shapes
-                            .iter()
-                            .find_map(|s| match &s.shape {
-                                egui::Shape::Text(text) if text.galley.text() == label && row.contains(text.pos) => Some((s.clip_rect, text)),
-                                _ => None,
-                            })
-                            .expect("navigation label is painted");
-                        let bounds = text.visual_bounding_rect();
-                        assert!(row.contains_rect(bounds.intersect(clip)), "{language} {percent}% {selected}: {label} paints outside {row:?}");
-                        if language == "en" && ["general", "display", "save"].contains(&id) {
-                            assert!(clip.contains_rect(bounds), "short labels must remain fully visible");
-                        }
-                    }
-                }
-            }
-        }
-    }
-
-    /// Clipping only the painter must leave the entire row clickable, its hover/selection
-    /// backgrounds intact, and the selected pane's settings visible at every interface size.
-    #[test]
-    fn options_nav_rows_keep_hover_and_selection() {
-        if !crate::i18n::catalogs_embedded() {
-            return;
-        }
-        for language in ["en", "ru"] {
-            for percent in [100, 125, 150] {
-                let mut h = nav_harness(language, percent);
-                for (id, setting) in
-                    [("display", "Spaces"), ("save", "Save documents"), ("accessibility", "Visual effects"), ("general", "Interface")]
-                {
-                    let lang = crate::i18n::Lang::from_pref(language);
-                    let row = h
-                        .query_all_by_label(crate::i18n::tr(lang, super::pane_label(id)))
-                        .find(|n| n.accesskit_node().toggled().is_some())
-                        .expect("pane has its full accessible name")
-                        .rect();
-                    // Both ends of the row, including its empty left inset, stay clickable.
-                    for x in [row.left() + 2.0, row.right() - 2.0] {
-                        h.state_mut().run("file.options", json!({"pane": "agents"})).unwrap();
-                        h.hover_at(egui::pos2(x, row.center().y));
-                        h.run_steps(4);
-                        let t = crate::theme::Tokens::get(&h.ctx);
-                        let background = |h: &egui_kittest::Harness<'_, WordApp>, color| {
-                            h.output().shapes.iter().any(|s| matches!(&s.shape, egui::Shape::Rect(r) if r.rect == row && r.fill == color))
-                        };
-                        assert!(background(&h, t.hover), "{language} {percent}%: hover covers the row");
-                        for pressed in [true, false] {
-                            h.input_mut().events.push(egui::Event::PointerButton {
-                                pos: egui::pos2(x, row.center().y),
-                                button: egui::PointerButton::Primary,
-                                pressed,
-                                modifiers: Default::default(),
-                            });
-                            h.run_steps(1);
-                        }
-                        h.run_steps(4);
-                        assert_eq!(h.state().ui.options_pane, id);
-                        assert!(background(&h, t.checked), "{language} {percent}%: selection covers the row");
-                        assert!(h.query_by_label(crate::i18n::tr(lang, setting)).is_some(), "{id} settings are shown");
-                    }
-                }
-            }
-        }
-    }
-
-    /// File › Options settings come back after a restart, and a `ui.json` with a wrong value in
-    /// one setting keeps every other setting (#485).
-    #[test]
-    fn options_survive_a_restart_and_junk_in_ui_json() {
-        let mut a = app();
-        a.run(
-            "file.options",
-            json!({"initials": "VK", "units": "centimeters", "typingReplacesSelection": false, "marks": {"tabs": true}, "ignoreNumbers": false, "addWords": ["zqxoptionsword"]}),
-        )
-        .unwrap();
-        a.ui.recent_count = 30;
-        a.ui.print_backgrounds = true;
-        let saved = serde_json::to_vec(&a.prefs()).unwrap();
-        let mut b = app();
-        b.apply_prefs(UiState::from_json(&saved).unwrap());
-        assert_eq!(b.session.prefs, a.session.prefs);
-        assert_eq!(b.session.prefs.units, Some(Unit::Centimeters));
-        assert_eq!(b.session.initials, "VK");
-        assert_eq!((b.ui.recent_count, b.ui.print_backgrounds), (30, true));
-        assert!(wordcraft_engine::proof::user_dictionary().contains(&"zqxoptionsword".to_string()));
-
-        let junk = br#"{"theme": "dark", "recentCount": "lots", "printBackgrounds": 7, "optionsPane": ["x"], "dark": true,
-            "editing": {"measurementUnits": "furlongs", "typingReplacesSelection": false, "marks": {"tabs": "yes", "spaces": true}}}"#;
-        let ui = UiState::from_json(junk).unwrap();
-        assert_eq!(ui.theme, Appearance::Dark);
-        assert_eq!((ui.recent_count, ui.print_backgrounds, ui.options_pane.as_str()), (12, false, "general"));
-        assert_eq!(ui.legacy_dark, Some(true));
-        assert_eq!(ui.editing.units, None);
-        assert!(!ui.editing.typing_replaces_selection);
-        assert!(ui.editing.marks.spaces && !ui.editing.marks.tabs);
-        assert!(UiState::from_json(b"[1, 2]").is_none() && UiState::from_json(b"not json").is_none());
-    }
-
-    /// The dictionaries folder (#1063) is saved with the settings and searched again after a
-    /// restart, before any document is checked.
-    #[test]
-    fn the_dictionaries_folder_survives_a_restart() {
-        let dir = std::env::temp_dir().join(format!("wc-ui-dictionaries-{}", std::process::id()));
-        std::fs::create_dir_all(&dir).unwrap();
-        let mut a = app();
-        a.run("file.options", json!({"dictionariesFolder": dir.to_string_lossy()})).unwrap();
-        let saved = serde_json::to_vec(&a.prefs()).unwrap();
-        wordcraft_engine::proof::hunspell::set_dictionary_dir(None);
-        let mut b = app();
-        b.apply_prefs(UiState::from_json(&saved).unwrap());
-        assert_eq!(b.session.prefs.dictionaries_folder.as_deref(), Some(dir.to_string_lossy().as_ref()));
-        assert_eq!(wordcraft_engine::proof::hunspell::search_dirs(None).first(), Some(&dir), "searched first");
-    }
-
-    /// #1792: Check spelling as you type is saved with the other proofing choices, so after a
-    /// restart the box comes back the way the user left it.
-    #[test]
-    fn check_spelling_survives_a_restart() {
-        let mut a = app();
-        a.run("file.options", json!({"checkSpelling": false})).unwrap();
-        assert!(!a.session.view.proofing, "off right away");
-        let saved = serde_json::to_value(a.prefs()).unwrap();
-        assert_eq!(saved["editing"]["checkSpelling"], false, "saved in ui.json");
-        let mut b = app();
-        b.apply_prefs(UiState::from_json(&serde_json::to_vec(&saved).unwrap()).unwrap());
-        assert!(!b.session.view.proofing, "spelling stays off after a restart");
-    }
-
-    /// Settings saved before #838 kept the unit under `editing.units` (default inches): a unit
-    /// the user chose carries over to `measurementUnits`; inches, junk or a newer value don't.
-    #[test]
-    fn a_unit_chosen_before_regions_survives_the_rename() {
-        let editing = |json: &str| UiState::from_json(format!(r#"{{"editing": {json}}}"#).as_bytes()).unwrap().editing.units;
-        assert_eq!(editing(r#"{"units": "centimeters"}"#), Some(Unit::Centimeters));
-        assert_eq!(editing(r#"{"units": "picas", "overtype": true}"#), Some(Unit::Picas));
-        assert_eq!(editing(r#"{"units": "inches"}"#), None);
-        assert_eq!(editing(r#"{"units": "furlongs"}"#), None);
-        assert_eq!(editing(r#"{"units": 7}"#), None);
-        assert_eq!(editing(r#"{"units": "millimeters", "measurementUnits": "points"}"#), Some(Unit::Points));
-        assert_eq!(editing(r#"{"units": "millimeters", "measurementUnits": null}"#), None);
-        assert_eq!(editing("{}"), None);
-        let mut a = app();
-        a.apply_prefs(UiState::from_json(br#"{"editing": {"units": "millimeters"}}"#).unwrap());
-        assert_eq!(a.session.units(), Unit::Millimeters);
-        // Saved again, it's under the new key.
-        let saved = serde_json::to_value(a.prefs()).unwrap();
-        assert_eq!(saved["editing"]["measurementUnits"], "millimeters");
-    }
-
-    /// `file.options` opens the page at a pane; the pane list switches panes, and their
-    /// checkboxes change the settings (#485).
-    #[test]
-    fn options_panes_open_and_change_settings() {
-        let mut a = app();
-        a.run("file.options", json!({"pane": "display"})).unwrap();
-        assert!(a.ui.backstage);
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(4);
-        h.get_by_label("Spaces").click();
-        h.run_steps(2);
-        assert!(h.state().session.prefs.marks.spaces, "Display › Spaces");
-        h.get_by_label("Proofing").click();
-        h.run_steps(4);
-        assert_eq!(h.state().ui.options_pane, "proofing");
-        h.get_by_label("Ignore words in capitals").click();
-        h.run_steps(2);
-        assert!(!h.state().session.prefs.ignore_uppercase);
-        // The AutoCorrect Options dialog opens from this pane.
-        assert!(h.state().dialog.is_none());
-        h.get_by_label("AutoCorrect Options").click();
-        h.run_steps(3);
-        assert_eq!(h.state().dialog.as_ref().map(|d| d.name()), Some("autoCorrect"));
-        h.state_mut().dialog = None;
-        h.run_steps(2);
-        // #1063: the dictionaries folder and the dictionary each language found.
-        assert!(h.query_by_label("Dictionaries folder:").is_some());
-        assert!(h.query_by_label_contains("Polish: ").is_some(), "the Polish dictionary's line");
-        h.get_by_label("Advanced").click();
-        h.run_steps(4);
-        h.get_by_label("Typing replaces selected text").click();
-        h.run_steps(2);
-        assert!(!h.state().session.prefs.typing_replaces_selection);
-        assert!(h.query_by_label("Measurement units:").is_some());
-    }
-
-    /// File › Options › Save › Privacy (#1062): the checkboxes are the document's
-    /// `file.privacyOptions` settings, and an undoable change like any other.
-    #[test]
-    fn save_privacy_checkboxes_set_the_privacy_options() {
-        let mut a = app();
-        a.run("file.options", json!({"pane": "save"})).unwrap();
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(4);
-        assert!(h.query_by_label("Privacy for this document").is_some(), "the section is there");
-        h.get_by_label("Remove my name from comments, changes and file properties when saving").click();
-        h.run_steps(4);
-        assert!(h.state().session.doc.settings.remove_personal_info);
-        assert!(!h.state().session.doc.settings.remove_date_time);
-        h.get_by_label("Leave out the date and time of comments and tracked changes when saving").click();
-        h.run_steps(4);
-        let privacy = h.state_mut().session.run("file.privacy", &json!({})).unwrap();
-        assert_eq!(privacy, json!({"removePersonalInfo": true, "removeDateTime": true}));
-        h.get_by_label("Remove my name from comments, changes and file properties when saving").click();
-        h.run_steps(4);
-        assert!(!h.state().session.doc.settings.remove_personal_info, "and off again");
-    }
-
-    /// File › Options › Accessibility › Animation effects: Use system setting (the default), On
-    /// or Off, with a line saying what the system's own setting is while it is followed.
-    #[test]
-    fn animation_effects_is_an_accessibility_option() {
-        use crate::theme::Animations;
-        let services = Services { animations_enabled: Some(Box::new(|| Some(false))), ..Default::default() };
-        let mut a = WordApp::new(wordcraft_engine::Session::new(wordcraft_doc::Document::new()), services);
-        a.run("file.options", json!({"pane": "accessibility"})).unwrap();
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(4);
-        assert_eq!(h.state().ui.animations, Animations::System);
-        assert!(h.query_by_label("Animation effects:").is_some());
-        assert!(h.query_by_label("Your system has animation effects turned off.").is_some());
-        assert!(!h.state().animations_on());
-        h.get_by_role_and_label(egui::accesskit::Role::ComboBox, "Animation effects:").click();
-        h.run_steps(4);
-        h.get_by_label("On").click();
-        h.run_steps(4);
-        assert_eq!(h.state().ui.animations, Animations::On);
-        assert!(h.state().animations_on());
-        assert!(h.query_by_label("Your system has animation effects turned off.").is_none(), "only said while the system is followed");
-    }
-
-    /// File › Options › General › Start-up (#766): the checkbox is the `ui.startScreen` setting.
-    #[test]
-    fn general_start_up_turns_the_start_screen_off_and_on() {
-        let mut a = app();
-        a.run("file.options", json!({"pane": "general"})).unwrap();
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(4);
-        assert!(h.query_by_label("Start-up").is_some(), "the section is there");
-        h.get_by_label("Show the Start screen when WordCraft starts").click();
-        h.run_steps(4);
-        assert!(!h.state().ui.start_screen, "the checkbox turns it off");
-        h.get_by_label("Show the Start screen when WordCraft starts").click();
-        h.run_steps(4);
-        assert!(h.state().ui.start_screen, "and on again");
-    }
-
-    /// File › Options › Advanced › Editing: the alignment guides checkbox is the
-    /// `ui.alignmentGuides` setting.
-    #[test]
-    fn advanced_alignment_guides_checkbox_turns_snapping_off_and_on() {
-        let mut a = app();
-        a.run("file.options", json!({"pane": "advanced"})).unwrap();
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(4);
-        let label = "Show alignment guides when moving pictures and shapes";
-        h.get_by_label(label).click();
-        h.run_steps(4);
-        assert!(!h.state().ui.alignment_guides, "the checkbox turns them off");
-        h.get_by_label(label).click();
-        h.run_steps(4);
-        assert!(h.state().ui.alignment_guides, "and on again");
-    }
-
-    /// File › Options › Advanced › Animation: the checkbox is the `ui.caretAnimation` setting,
-    /// and the section is translated.
-    #[test]
-    fn advanced_animation_turns_the_caret_animation_off_and_on() {
-        let mut a = app();
-        a.run("file.options", json!({"pane": "advanced"})).unwrap();
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(4);
-        assert!(h.query_by_label("Animation").is_some(), "the section is there");
-        h.get_by_label("Animate the caret (it glides and fades)").click();
-        h.run_steps(4);
-        assert!(!h.state().ui.caret_animation, "the checkbox turns it off");
-        h.get_by_label("Animate the caret (it glides and fades)").click();
-        h.run_steps(4);
-        assert!(h.state().ui.caret_animation, "and on again");
-        if !crate::i18n::catalogs_embedded() {
-            return;
-        }
-        h.state_mut().run("ui.language", json!({"value": "es"})).unwrap();
-        h.run_steps(4);
-        assert!(h.query_by_label("Animación").is_some() && h.query_by_label("Animation").is_none());
-    }
-
-    /// #838: in a Polish region the Page Setup margins read `2,54 cm` (the region's unit and
-    /// decimal comma), a typed `3,5` or `1 in` is understood, and the Options page shows the
-    /// region's unit until the user picks another.
-    #[test]
-    fn length_fields_follow_the_region() {
-        let mut a = app();
-        a.run("file.options", json!({"region": "pl-PL"})).unwrap();
-        a.run("file.new", json!({})).unwrap();
-        assert_eq!(wordcraft_geom::paper_name(a.session.doc.last_section.page_w, a.session.doc.last_section.page_h), Some("A4"));
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(2);
-        // The dialog reads the unit when it opens, after a frame has picked up the region.
-        h.state_mut().run("ui.dialog", json!({"name": "pageSetup"})).unwrap();
-        h.run_steps(4);
-        assert_eq!((unit(), decimal()), (Unit::Centimeters, ','));
-        assert_eq!(length(72.0), "2,54 cm");
-        assert_eq!(h.query_all_by_value("2,54 cm").count(), 4, "four margins in centimetres with a decimal comma");
-
-        h.state_mut().run("file.options", json!({"units": "inches"})).unwrap();
-        h.run_steps(4);
-        assert_eq!(length(108.0), "1,5\"", "the user's unit, still the region's decimal comma");
-        h.state_mut().run("file.options", json!({"units": "auto", "region": "en-US"})).unwrap();
-        h.run_steps(4);
-        assert_eq!(length(72.0), "1\"");
-    }
-
-    /// #1734: a Russian interface shows centimetres as `см`, as Word does, and a length field
-    /// takes the unit typed either way.
-    #[test]
-    fn length_units_follow_the_interface_language() {
-        if !crate::i18n::catalogs_embedded() {
-            return;
-        }
-        let mut a = app();
-        a.run("ui.language", json!({"value": "ru"})).unwrap();
-        a.run("file.options", json!({"region": "ru-RU"})).unwrap();
-        a.run("file.new", json!({})).unwrap();
-        let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
-            |ui, app: &mut WordApp| {
-                let ctx = ui.ctx().clone();
-                app.logic(&ctx);
-                app.ui(ui);
-            },
-            a,
-        );
-        h.run_steps(2);
-        h.state_mut().run("ui.dialog", json!({"name": "pageSetup"})).unwrap();
-        h.run_steps(4);
-        assert_eq!((unit(), decimal()), (Unit::Centimeters, ','));
-        assert_eq!(length(72.0), "2,54 см");
-        assert_eq!(h.query_all_by_value("2,54 см").count(), 4, "four margins in centimetres, named in Russian");
-        assert_eq!(h.query_all_by_value("2,54 cm").count(), 0);
-        assert_eq!(parse_length("3 см", Unit::Centimeters), Some(3.0));
-        assert_eq!(parse_length("3cm", Unit::Centimeters), Some(3.0));
-        assert_eq!(parse_length("10 мм", Unit::Centimeters).map(|v| (v * 100.0).round() / 100.0), Some(1.0));
-        assert_eq!(parse_length("72 пт", Unit::Centimeters).map(|v| (v * 100.0).round() / 100.0), Some(2.54));
-
-        h.state_mut().run("file.options", json!({"units": "millimeters"})).unwrap();
-        h.run_steps(4);
-        assert_eq!(length(72.0), "25,4 мм");
-        h.state_mut().run("ui.language", json!({"value": "en"})).unwrap();
-        h.run_steps(4);
-        assert_eq!(length(72.0), "25,4 mm", "English keeps the English names");
-    }
-}
+mod tests;
diff --git a/crates/ui-egui/src/options/tests.rs b/crates/ui-egui/src/options/tests.rs
new file mode 100644
index 000000000..3bb85f05c
--- /dev/null
+++ b/crates/ui-egui/src/options/tests.rs
@@ -0,0 +1,479 @@
+use egui_kittest::kittest::{NodeT, Queryable};
+use serde_json::json;
+use wordcraft_geom::Unit;
+
+use super::{decimal, length, parse_length, unit};
+
+use crate::theme::Appearance;
+use crate::{Services, UiState, WordApp};
+
+#[test]
+fn unknown_settings_keys_load_in_linear_time() {
+    let mut map = serde_json::Map::new();
+    for i in 0..20_000 {
+        map.insert(format!("unknownKey{i}"), json!(i));
+    }
+    map.insert("miniToolbar".into(), json!(false));
+    let bytes = serde_json::to_vec(&serde_json::Value::Object(map)).unwrap();
+    let state = UiState::from_json(&bytes).unwrap();
+    assert!(!state.mini_toolbar);
+}
+
+fn app() -> WordApp {
+    WordApp::new(wordcraft_engine::Session::new(wordcraft_doc::Document::new()), Services::default())
+}
+
+fn nav_harness(language: &str, percent: u16) -> egui_kittest::Harness<'static, WordApp> {
+    let mut a = app();
+    a.run("ui.language", json!({"value": language})).unwrap();
+    a.run("ui.interfaceSize", json!({"percent": percent})).unwrap();
+    a.run("file.options", json!({"pane": "general"})).unwrap();
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).with_pixels_per_point(2.0).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(4);
+    h
+}
+
+/// File › Options must not offer a way around the protected document's author check.
+#[test]
+fn user_name_field_disables_when_protection_starts() {
+    let mut h = nav_harness("en", 100);
+    let user_name = || egui_kittest::kittest::By::new().role(egui::accesskit::Role::TextInput).value("WordCraft User");
+    assert!(!h.get(user_name()).accesskit_node().is_disabled());
+    h.state_mut().run("review.restrict", json!({"mode": "readOnly"})).unwrap();
+    h.run_steps(4);
+    assert!(h.get(user_name()).accesskit_node().is_disabled());
+}
+
+/// #1266: check the actual painted text and renderer clip, including the bold selected
+/// label. AccessKit must still expose the full name and the row must keep its fixed size.
+#[test]
+fn options_nav_labels_stay_inside_their_rows() {
+    if !crate::i18n::catalogs_embedded() {
+        return;
+    }
+    for language in ["en", "ru"] {
+        for percent in [100, 125, 150] {
+            let mut h = nav_harness(language, percent);
+            // An interface size is absolute (#822): `percent` points per 100 screen pixels,
+            // whatever the display's own scale (2.0 here).
+            assert_eq!(h.ctx.pixels_per_point(), f32::from(percent) / 100.0);
+            for selected in ["general", "accessibility"] {
+                h.state_mut().run("file.options", json!({"pane": selected})).unwrap();
+                h.run_steps(4);
+                for id in wordcraft_engine::cmd::options::PANES {
+                    let label = crate::i18n::tr(crate::i18n::Lang::from_pref(language), super::pane_label(id));
+                    let node =
+                        h.query_all_by_label(label).find(|n| n.accesskit_node().toggled().is_some()).expect("pane has its full accessible name");
+                    assert_eq!(
+                        node.accesskit_node().toggled(),
+                        Some(if id == selected { egui::accesskit::Toggled::True } else { egui::accesskit::Toggled::False })
+                    );
+                    let row = node.rect();
+                    assert_eq!(row.size(), egui::vec2(170.0, 30.0));
+                    let (clip, text) = h
+                        .output()
+                        .shapes
+                        .iter()
+                        .find_map(|s| match &s.shape {
+                            egui::Shape::Text(text) if text.galley.text() == label && row.contains(text.pos) => Some((s.clip_rect, text)),
+                            _ => None,
+                        })
+                        .expect("navigation label is painted");
+                    let bounds = text.visual_bounding_rect();
+                    assert!(row.contains_rect(bounds.intersect(clip)), "{language} {percent}% {selected}: {label} paints outside {row:?}");
+                    if language == "en" && ["general", "display", "save"].contains(&id) {
+                        assert!(clip.contains_rect(bounds), "short labels must remain fully visible");
+                    }
+                }
+            }
+        }
+    }
+}
+
+/// Clipping only the painter must leave the entire row clickable, its hover/selection
+/// backgrounds intact, and the selected pane's settings visible at every interface size.
+#[test]
+fn options_nav_rows_keep_hover_and_selection() {
+    if !crate::i18n::catalogs_embedded() {
+        return;
+    }
+    for language in ["en", "ru"] {
+        for percent in [100, 125, 150] {
+            let mut h = nav_harness(language, percent);
+            for (id, setting) in [("display", "Spaces"), ("save", "Save documents"), ("accessibility", "Visual effects"), ("general", "Interface")] {
+                let lang = crate::i18n::Lang::from_pref(language);
+                let row = h
+                    .query_all_by_label(crate::i18n::tr(lang, super::pane_label(id)))
+                    .find(|n| n.accesskit_node().toggled().is_some())
+                    .expect("pane has its full accessible name")
+                    .rect();
+                // Both ends of the row, including its empty left inset, stay clickable.
+                for x in [row.left() + 2.0, row.right() - 2.0] {
+                    h.state_mut().run("file.options", json!({"pane": "agents"})).unwrap();
+                    h.hover_at(egui::pos2(x, row.center().y));
+                    h.run_steps(4);
+                    let t = crate::theme::Tokens::get(&h.ctx);
+                    let background = |h: &egui_kittest::Harness<'_, WordApp>, color| {
+                        h.output().shapes.iter().any(|s| matches!(&s.shape, egui::Shape::Rect(r) if r.rect == row && r.fill == color))
+                    };
+                    assert!(background(&h, t.hover), "{language} {percent}%: hover covers the row");
+                    for pressed in [true, false] {
+                        h.input_mut().events.push(egui::Event::PointerButton {
+                            pos: egui::pos2(x, row.center().y),
+                            button: egui::PointerButton::Primary,
+                            pressed,
+                            modifiers: Default::default(),
+                        });
+                        h.run_steps(1);
+                    }
+                    h.run_steps(4);
+                    assert_eq!(h.state().ui.options_pane, id);
+                    assert!(background(&h, t.checked), "{language} {percent}%: selection covers the row");
+                    assert!(h.query_by_label(crate::i18n::tr(lang, setting)).is_some(), "{id} settings are shown");
+                }
+            }
+        }
+    }
+}
+
+/// File › Options settings come back after a restart, and a `ui.json` with a wrong value in
+/// one setting keeps every other setting (#485).
+#[test]
+fn options_survive_a_restart_and_junk_in_ui_json() {
+    let mut a = app();
+    a.run(
+        "file.options",
+        json!({"initials": "VK", "units": "centimeters", "typingReplacesSelection": false, "marks": {"tabs": true}, "ignoreNumbers": false, "addWords": ["zqxoptionsword"]}),
+    )
+    .unwrap();
+    a.ui.recent_count = 30;
+    a.ui.print_backgrounds = true;
+    let saved = serde_json::to_vec(&a.prefs()).unwrap();
+    let mut b = app();
+    b.apply_prefs(UiState::from_json(&saved).unwrap());
+    assert_eq!(b.session.prefs, a.session.prefs);
+    assert_eq!(b.session.prefs.units, Some(Unit::Centimeters));
+    assert_eq!(b.session.initials, "VK");
+    assert_eq!((b.ui.recent_count, b.ui.print_backgrounds), (30, true));
+    assert!(wordcraft_engine::proof::user_dictionary().contains(&"zqxoptionsword".to_string()));
+
+    let junk = br#"{"theme": "dark", "recentCount": "lots", "printBackgrounds": 7, "optionsPane": ["x"], "dark": true,
+            "editing": {"measurementUnits": "furlongs", "typingReplacesSelection": false, "marks": {"tabs": "yes", "spaces": true}}}"#;
+    let ui = UiState::from_json(junk).unwrap();
+    assert_eq!(ui.theme, Appearance::Dark);
+    assert_eq!((ui.recent_count, ui.print_backgrounds, ui.options_pane.as_str()), (12, false, "general"));
+    assert_eq!(ui.legacy_dark, Some(true));
+    assert_eq!(ui.editing.units, None);
+    assert!(!ui.editing.typing_replaces_selection);
+    assert!(ui.editing.marks.spaces && !ui.editing.marks.tabs);
+    assert!(UiState::from_json(b"[1, 2]").is_none() && UiState::from_json(b"not json").is_none());
+}
+
+/// The dictionaries folder (#1063) is saved with the settings and searched again after a
+/// restart, before any document is checked.
+#[test]
+fn the_dictionaries_folder_survives_a_restart() {
+    let dir = std::env::temp_dir().join(format!("wc-ui-dictionaries-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let mut a = app();
+    a.run("file.options", json!({"dictionariesFolder": dir.to_string_lossy()})).unwrap();
+    let saved = serde_json::to_vec(&a.prefs()).unwrap();
+    wordcraft_engine::proof::hunspell::set_dictionary_dir(None);
+    let mut b = app();
+    b.apply_prefs(UiState::from_json(&saved).unwrap());
+    assert_eq!(b.session.prefs.dictionaries_folder.as_deref(), Some(dir.to_string_lossy().as_ref()));
+    assert_eq!(wordcraft_engine::proof::hunspell::search_dirs(None).first(), Some(&dir), "searched first");
+}
+
+/// #1792: Check spelling as you type is saved with the other proofing choices, so after a
+/// restart the box comes back the way the user left it.
+#[test]
+fn check_spelling_survives_a_restart() {
+    let mut a = app();
+    a.run("file.options", json!({"checkSpelling": false})).unwrap();
+    assert!(!a.session.view.proofing, "off right away");
+    let saved = serde_json::to_value(a.prefs()).unwrap();
+    assert_eq!(saved["editing"]["checkSpelling"], false, "saved in ui.json");
+    let mut b = app();
+    b.apply_prefs(UiState::from_json(&serde_json::to_vec(&saved).unwrap()).unwrap());
+    assert!(!b.session.view.proofing, "spelling stays off after a restart");
+}
+
+/// Settings saved before #838 kept the unit under `editing.units` (default inches): a unit
+/// the user chose carries over to `measurementUnits`; inches, junk or a newer value don't.
+#[test]
+fn a_unit_chosen_before_regions_survives_the_rename() {
+    let editing = |json: &str| UiState::from_json(format!(r#"{{"editing": {json}}}"#).as_bytes()).unwrap().editing.units;
+    assert_eq!(editing(r#"{"units": "centimeters"}"#), Some(Unit::Centimeters));
+    assert_eq!(editing(r#"{"units": "picas", "overtype": true}"#), Some(Unit::Picas));
+    assert_eq!(editing(r#"{"units": "inches"}"#), None);
+    assert_eq!(editing(r#"{"units": "furlongs"}"#), None);
+    assert_eq!(editing(r#"{"units": 7}"#), None);
+    assert_eq!(editing(r#"{"units": "millimeters", "measurementUnits": "points"}"#), Some(Unit::Points));
+    assert_eq!(editing(r#"{"units": "millimeters", "measurementUnits": null}"#), None);
+    assert_eq!(editing("{}"), None);
+    let mut a = app();
+    a.apply_prefs(UiState::from_json(br#"{"editing": {"units": "millimeters"}}"#).unwrap());
+    assert_eq!(a.session.units(), Unit::Millimeters);
+    // Saved again, it's under the new key.
+    let saved = serde_json::to_value(a.prefs()).unwrap();
+    assert_eq!(saved["editing"]["measurementUnits"], "millimeters");
+}
+
+/// `file.options` opens the page at a pane; the pane list switches panes, and their
+/// checkboxes change the settings (#485).
+#[test]
+fn options_panes_open_and_change_settings() {
+    let mut a = app();
+    a.run("file.options", json!({"pane": "display"})).unwrap();
+    assert!(a.ui.backstage);
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(4);
+    h.get_by_label("Spaces").click();
+    h.run_steps(2);
+    assert!(h.state().session.prefs.marks.spaces, "Display › Spaces");
+    h.get_by_label("Proofing").click();
+    h.run_steps(4);
+    assert_eq!(h.state().ui.options_pane, "proofing");
+    h.get_by_label("Ignore words in capitals").click();
+    h.run_steps(2);
+    assert!(!h.state().session.prefs.ignore_uppercase);
+    // The AutoCorrect Options dialog opens from this pane.
+    assert!(h.state().dialog.is_none());
+    h.get_by_label("AutoCorrect Options").click();
+    h.run_steps(3);
+    assert_eq!(h.state().dialog.as_ref().map(|d| d.name()), Some("autoCorrect"));
+    h.state_mut().dialog = None;
+    h.run_steps(2);
+    // #1063: the dictionaries folder and the dictionary each language found.
+    assert!(h.query_by_label("Dictionaries folder:").is_some());
+    assert!(h.query_by_label_contains("Polish: ").is_some(), "the Polish dictionary's line");
+    h.get_by_label("Advanced").click();
+    h.run_steps(4);
+    h.get_by_label("Typing replaces selected text").click();
+    h.run_steps(2);
+    assert!(!h.state().session.prefs.typing_replaces_selection);
+    assert!(h.query_by_label("Measurement units:").is_some());
+}
+
+/// File › Options › Save › Privacy (#1062): the checkboxes are the document's
+/// `file.privacyOptions` settings, and an undoable change like any other.
+#[test]
+fn save_privacy_checkboxes_set_the_privacy_options() {
+    let mut a = app();
+    a.run("file.options", json!({"pane": "save"})).unwrap();
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(4);
+    assert!(h.query_by_label("Privacy for this document").is_some(), "the section is there");
+    h.get_by_label("Remove my name from comments, changes and file properties when saving").click();
+    h.run_steps(4);
+    assert!(h.state().session.doc.settings.remove_personal_info);
+    assert!(!h.state().session.doc.settings.remove_date_time);
+    h.get_by_label("Leave out the date and time of comments and tracked changes when saving").click();
+    h.run_steps(4);
+    let privacy = h.state_mut().session.run("file.privacy", &json!({})).unwrap();
+    assert_eq!(privacy, json!({"removePersonalInfo": true, "removeDateTime": true}));
+    h.get_by_label("Remove my name from comments, changes and file properties when saving").click();
+    h.run_steps(4);
+    assert!(!h.state().session.doc.settings.remove_personal_info, "and off again");
+}
+
+/// File › Options › Accessibility › Animation effects: Use system setting (the default), On
+/// or Off, with a line saying what the system's own setting is while it is followed.
+#[test]
+fn animation_effects_is_an_accessibility_option() {
+    use crate::theme::Animations;
+    let services = Services { animations_enabled: Some(Box::new(|| Some(false))), ..Default::default() };
+    let mut a = WordApp::new(wordcraft_engine::Session::new(wordcraft_doc::Document::new()), services);
+    a.run("file.options", json!({"pane": "accessibility"})).unwrap();
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(4);
+    assert_eq!(h.state().ui.animations, Animations::System);
+    assert!(h.query_by_label("Animation effects:").is_some());
+    assert!(h.query_by_label("Your system has animation effects turned off.").is_some());
+    assert!(!h.state().animations_on());
+    h.get_by_role_and_label(egui::accesskit::Role::ComboBox, "Animation effects:").click();
+    h.run_steps(4);
+    h.get_by_label("On").click();
+    h.run_steps(4);
+    assert_eq!(h.state().ui.animations, Animations::On);
+    assert!(h.state().animations_on());
+    assert!(h.query_by_label("Your system has animation effects turned off.").is_none(), "only said while the system is followed");
+}
+
+/// File › Options › General › Start-up (#766): the checkbox is the `ui.startScreen` setting.
+#[test]
+fn general_start_up_turns_the_start_screen_off_and_on() {
+    let mut a = app();
+    a.run("file.options", json!({"pane": "general"})).unwrap();
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(4);
+    assert!(h.query_by_label("Start-up").is_some(), "the section is there");
+    h.get_by_label("Show the Start screen when WordCraft starts").click();
+    h.run_steps(4);
+    assert!(!h.state().ui.start_screen, "the checkbox turns it off");
+    h.get_by_label("Show the Start screen when WordCraft starts").click();
+    h.run_steps(4);
+    assert!(h.state().ui.start_screen, "and on again");
+}
+
+/// File › Options › Advanced › Editing: the alignment guides checkbox is the
+/// `ui.alignmentGuides` setting.
+#[test]
+fn advanced_alignment_guides_checkbox_turns_snapping_off_and_on() {
+    let mut a = app();
+    a.run("file.options", json!({"pane": "advanced"})).unwrap();
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(4);
+    let label = "Show alignment guides when moving pictures and shapes";
+    h.get_by_label(label).click();
+    h.run_steps(4);
+    assert!(!h.state().ui.alignment_guides, "the checkbox turns them off");
+    h.get_by_label(label).click();
+    h.run_steps(4);
+    assert!(h.state().ui.alignment_guides, "and on again");
+}
+
+/// File › Options › Advanced › Animation: the checkbox is the `ui.caretAnimation` setting,
+/// and the section is translated.
+#[test]
+fn advanced_animation_turns_the_caret_animation_off_and_on() {
+    let mut a = app();
+    a.run("file.options", json!({"pane": "advanced"})).unwrap();
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(4);
+    assert!(h.query_by_label("Animation").is_some(), "the section is there");
+    h.get_by_label("Animate the caret (it glides and fades)").click();
+    h.run_steps(4);
+    assert!(!h.state().ui.caret_animation, "the checkbox turns it off");
+    h.get_by_label("Animate the caret (it glides and fades)").click();
+    h.run_steps(4);
+    assert!(h.state().ui.caret_animation, "and on again");
+    if !crate::i18n::catalogs_embedded() {
+        return;
+    }
+    h.state_mut().run("ui.language", json!({"value": "es"})).unwrap();
+    h.run_steps(4);
+    assert!(h.query_by_label("Animación").is_some() && h.query_by_label("Animation").is_none());
+}
+
+/// #838: in a Polish region the Page Setup margins read `2,54 cm` (the region's unit and
+/// decimal comma), a typed `3,5` or `1 in` is understood, and the Options page shows the
+/// region's unit until the user picks another.
+#[test]
+fn length_fields_follow_the_region() {
+    let mut a = app();
+    a.run("file.options", json!({"region": "pl-PL"})).unwrap();
+    a.run("file.new", json!({})).unwrap();
+    assert_eq!(wordcraft_geom::paper_name(a.session.doc.last_section.page_w, a.session.doc.last_section.page_h), Some("A4"));
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(2);
+    // The dialog reads the unit when it opens, after a frame has picked up the region.
+    h.state_mut().run("ui.dialog", json!({"name": "pageSetup"})).unwrap();
+    h.run_steps(4);
+    assert_eq!((unit(), decimal()), (Unit::Centimeters, ','));
+    assert_eq!(length(72.0), "2,54 cm");
+    assert_eq!(h.query_all_by_value("2,54 cm").count(), 4, "four margins in centimetres with a decimal comma");
+
+    h.state_mut().run("file.options", json!({"units": "inches"})).unwrap();
+    h.run_steps(4);
+    assert_eq!(length(108.0), "1,5\"", "the user's unit, still the region's decimal comma");
+    h.state_mut().run("file.options", json!({"units": "auto", "region": "en-US"})).unwrap();
+    h.run_steps(4);
+    assert_eq!(length(72.0), "1\"");
+}
+
+/// #1734: a Russian interface shows centimetres as `см`, as Word does, and a length field
+/// takes the unit typed either way.
+#[test]
+fn length_units_follow_the_interface_language() {
+    if !crate::i18n::catalogs_embedded() {
+        return;
+    }
+    let mut a = app();
+    a.run("ui.language", json!({"value": "ru"})).unwrap();
+    a.run("file.options", json!({"region": "ru-RU"})).unwrap();
+    a.run("file.new", json!({})).unwrap();
+    let mut h = egui_kittest::Harness::builder().with_size(egui::vec2(1440.0, 900.0)).build_ui_state(
+        |ui, app: &mut WordApp| {
+            let ctx = ui.ctx().clone();
+            app.logic(&ctx);
+            app.ui(ui);
+        },
+        a,
+    );
+    h.run_steps(2);
+    h.state_mut().run("ui.dialog", json!({"name": "pageSetup"})).unwrap();
+    h.run_steps(4);
+    assert_eq!((unit(), decimal()), (Unit::Centimeters, ','));
+    assert_eq!(length(72.0), "2,54 см");
+    assert_eq!(h.query_all_by_value("2,54 см").count(), 4, "four margins in centimetres, named in Russian");
+    assert_eq!(h.query_all_by_value("2,54 cm").count(), 0);
+    assert_eq!(parse_length("3 см", Unit::Centimeters), Some(3.0));
+    assert_eq!(parse_length("3cm", Unit::Centimeters), Some(3.0));
+    assert_eq!(parse_length("10 мм", Unit::Centimeters).map(|v| (v * 100.0).round() / 100.0), Some(1.0));
+    assert_eq!(parse_length("72 пт", Unit::Centimeters).map(|v| (v * 100.0).round() / 100.0), Some(2.54));
+
+    h.state_mut().run("file.options", json!({"units": "millimeters"})).unwrap();
+    h.run_steps(4);
+    assert_eq!(length(72.0), "25,4 мм");
+    h.state_mut().run("ui.language", json!({"value": "en"})).unwrap();
+    h.run_steps(4);
+    assert_eq!(length(72.0), "25,4 mm", "English keeps the English names");
+}