diff --git a/CLAUDE.md b/CLAUDE.md
index d3dfe7e..5138644 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -120,6 +120,35 @@ Add hint text to both `en.json` and `ru.json` locale files using a `.hint` suffi
 
 Do **not** add placeholder options like `-- Select something --`. Populate the `<select>` with real options only and let the first one be selected by default.
 
+### Modal dirty check (discard unsaved changes)
+
+Every editor modal **must** have a dirty check so closing with unsaved changes shows a "Discard unsaved changes?" confirmation. Use the `Modal` base class pattern from `js/core/modal.js`:
+
+1. **Subclass Modal** with `snapshotValues()` returning an object of all tracked field values:
+
+   ```javascript
+   class MyEditorModal extends Modal {
+       constructor() { super('my-modal-id'); }
+       snapshotValues() {
+           return {
+               name: document.getElementById('my-name').value,
+               // ... all form fields
+           };
+       }
+       onForceClose() {
+           // Optional: cleanup (reset flags, clear state, etc.)
+       }
+   }
+   const myModal = new MyEditorModal();
+   ```
+
+2. **Call `modal.snapshot()`** after the form is fully populated (after `modal.open()`).
+3. **Close/cancel button** calls `await modal.close()` — triggers dirty check + confirmation.
+4. **Save function** calls `modal.forceClose()` after successful save — skips dirty check.
+5. For complex/dynamic state (filter lists, schedule rows, conditions), serialize to JSON string in `snapshotValues()`.
+
+The base class handles: `isDirty()` comparison, confirmation dialog, backdrop click, ESC key, focus trapping, and body scroll lock.
+
 ## General Guidelines
 
 - Always test changes before marking as complete
diff --git a/server/src/wled_controller/static/js/features/audio-sources.js b/server/src/wled_controller/static/js/features/audio-sources.js
index 03953a7..c13785a 100644
--- a/server/src/wled_controller/static/js/features/audio-sources.js
+++ b/server/src/wled_controller/static/js/features/audio-sources.js
@@ -17,7 +17,22 @@ import { showToast, showConfirm } from '../core/ui.js';
 import { Modal } from '../core/modal.js';
 import { loadPictureSources } from './streams.js';
 
-const audioSourceModal = new Modal('audio-source-modal');
+class AudioSourceModal extends Modal {
+    constructor() { super('audio-source-modal'); }
+
+    snapshotValues() {
+        return {
+            name: document.getElementById('audio-source-name').value,
+            description: document.getElementById('audio-source-description').value,
+            type: document.getElementById('audio-source-type').value,
+            device: document.getElementById('audio-source-device').value,
+            parent: document.getElementById('audio-source-parent').value,
+            channel: document.getElementById('audio-source-channel').value,
+        };
+    }
+}
+
+const audioSourceModal = new AudioSourceModal();
 
 // ── Modal ─────────────────────────────────────────────────────
 
@@ -60,10 +75,11 @@ export async function showAudioSourceModal(sourceType, editData) {
     }
 
     audioSourceModal.open();
+    audioSourceModal.snapshot();
 }
 
-export function closeAudioSourceModal() {
-    audioSourceModal.forceClose();
+export async function closeAudioSourceModal() {
+    await audioSourceModal.close();
 }
 
 export function onAudioSourceTypeChange() {
diff --git a/server/src/wled_controller/static/js/features/device-discovery.js b/server/src/wled_controller/static/js/features/device-discovery.js
index 564957b..42dbbe7 100644
--- a/server/src/wled_controller/static/js/features/device-discovery.js
+++ b/server/src/wled_controller/static/js/features/device-discovery.js
@@ -12,7 +12,22 @@ import { showToast } from '../core/ui.js';
 import { Modal } from '../core/modal.js';
 import { _computeMaxFps, _renderFpsHint } from './devices.js';
 
-const addDeviceModal = new Modal('add-device-modal');
+class AddDeviceModal extends Modal {
+    constructor() { super('add-device-modal'); }
+
+    snapshotValues() {
+        return {
+            name: document.getElementById('device-name').value,
+            type: document.getElementById('device-type').value,
+            url: document.getElementById('device-url').value,
+            serialPort: document.getElementById('device-serial-port').value,
+            ledCount: document.getElementById('device-led-count').value,
+            baudRate: document.getElementById('device-baud-rate').value,
+        };
+    }
+}
+
+const addDeviceModal = new AddDeviceModal();
 
 export function onDeviceTypeChanged() {
     const deviceType = document.getElementById('device-type').value;
@@ -175,11 +190,14 @@ export function showAddDevice() {
     if (scanBtn) scanBtn.disabled = false;
     addDeviceModal.open();
     onDeviceTypeChanged();
-    setTimeout(() => document.getElementById('device-name').focus(), 100);
+    setTimeout(() => {
+        document.getElementById('device-name').focus();
+        addDeviceModal.snapshot();
+    }, 100);
 }
 
-export function closeAddDeviceModal() {
-    addDeviceModal.forceClose();
+export async function closeAddDeviceModal() {
+    await addDeviceModal.close();
 }
 
 export async function scanForDevices(forceType) {
@@ -304,7 +322,7 @@ export async function handleAddDevice(event) {
             const result = await response.json();
             console.log('Device added successfully:', result);
             showToast('Device added successfully', 'success');
-            closeAddDeviceModal();
+            addDeviceModal.forceClose();
             // Use window.* to avoid circular imports
             if (typeof window.loadDevices === 'function') await window.loadDevices();
             // Auto-start device tutorial on first device add
diff --git a/server/src/wled_controller/static/js/features/profiles.js b/server/src/wled_controller/static/js/features/profiles.js
index f98b773..c18c3f5 100644
--- a/server/src/wled_controller/static/js/features/profiles.js
+++ b/server/src/wled_controller/static/js/features/profiles.js
@@ -9,7 +9,21 @@ import { showToast, showConfirm } from '../core/ui.js';
 import { Modal } from '../core/modal.js';
 import { CardSection } from '../core/card-sections.js';
 
-const profileModal = new Modal('profile-editor-modal');
+class ProfileEditorModal extends Modal {
+    constructor() { super('profile-editor-modal'); }
+
+    snapshotValues() {
+        return {
+            name: document.getElementById('profile-editor-name').value,
+            enabled: document.getElementById('profile-editor-enabled').checked.toString(),
+            logic: document.getElementById('profile-editor-logic').value,
+            conditions: JSON.stringify(getProfileEditorConditions()),
+            targets: JSON.stringify(getProfileEditorTargetIds()),
+        };
+    }
+}
+
+const profileModal = new ProfileEditorModal();
 const csProfiles = new CardSection('profiles', { titleKey: 'profiles.title', gridClass: 'devices-grid', addCardOnclick: "openProfileEditor()" });
 
 // Re-render profiles when language changes (only if tab is active)
@@ -176,10 +190,11 @@ export async function openProfileEditor(profileId) {
     modal.querySelectorAll('[data-i18n]').forEach(el => {
         el.textContent = t(el.getAttribute('data-i18n'));
     });
+    profileModal.snapshot();
 }
 
-export function closeProfileEditorModal() {
-    profileModal.forceClose();
+export async function closeProfileEditorModal() {
+    await profileModal.close();
 }
 
 async function loadProfileTargetChecklist(selectedIds) {
diff --git a/server/src/wled_controller/static/js/features/streams.js b/server/src/wled_controller/static/js/features/streams.js
index 44ab5ec..ef24c97 100644
--- a/server/src/wled_controller/static/js/features/streams.js
+++ b/server/src/wled_controller/static/js/features/streams.js
@@ -45,11 +45,72 @@ document.addEventListener('languageChanged', () => { if (apiKey) loadPictureSour
 
 // ===== Modal instances =====
 
-const templateModal = new Modal('template-modal');
+class CaptureTemplateModal extends Modal {
+    constructor() { super('template-modal'); }
+
+    snapshotValues() {
+        const vals = {
+            name: document.getElementById('template-name').value,
+            description: document.getElementById('template-description').value,
+            engine: document.getElementById('template-engine').value,
+        };
+        document.querySelectorAll('[data-config-key]').forEach(field => {
+            vals['cfg_' + field.dataset.configKey] = field.value;
+        });
+        return vals;
+    }
+
+    onForceClose() {
+        setCurrentEditingTemplateId(null);
+        set_templateNameManuallyEdited(false);
+    }
+}
+
+class StreamEditorModal extends Modal {
+    constructor() { super('stream-modal'); }
+
+    snapshotValues() {
+        return {
+            name: document.getElementById('stream-name').value,
+            description: document.getElementById('stream-description').value,
+            type: document.getElementById('stream-type').value,
+            displayIndex: document.getElementById('stream-display-index').value,
+            captureTemplate: document.getElementById('stream-capture-template').value,
+            targetFps: document.getElementById('stream-target-fps').value,
+            source: document.getElementById('stream-source').value,
+            ppTemplate: document.getElementById('stream-pp-template').value,
+            imageSource: document.getElementById('stream-image-source').value,
+        };
+    }
+
+    onForceClose() {
+        document.getElementById('stream-type').disabled = false;
+        set_streamNameManuallyEdited(false);
+    }
+}
+
+class PPTemplateEditorModal extends Modal {
+    constructor() { super('pp-template-modal'); }
+
+    snapshotValues() {
+        return {
+            name: document.getElementById('pp-template-name').value,
+            description: document.getElementById('pp-template-description').value,
+            filters: JSON.stringify(_modalFilters.map(fi => ({ filter_id: fi.filter_id, options: fi.options }))),
+        };
+    }
+
+    onForceClose() {
+        set_modalFilters([]);
+        set_ppTemplateNameManuallyEdited(false);
+    }
+}
+
+const templateModal = new CaptureTemplateModal();
 const testTemplateModal = new Modal('test-template-modal');
-const streamModal = new Modal('stream-modal');
+const streamModal = new StreamEditorModal();
 const testStreamModal = new Modal('test-stream-modal');
-const ppTemplateModal = new Modal('pp-template-modal');
+const ppTemplateModal = new PPTemplateEditorModal();
 const testPPTemplateModal = new Modal('test-pp-template-modal');
 
 // ===== Capture Templates =====
@@ -94,6 +155,7 @@ export async function showAddTemplateModal(cloneData = null) {
     }
 
     templateModal.open();
+    templateModal.snapshot();
 }
 
 export async function editTemplate(templateId) {
@@ -120,16 +182,15 @@ export async function editTemplate(templateId) {
         document.getElementById('template-error').style.display = 'none';
 
         templateModal.open();
+        templateModal.snapshot();
     } catch (error) {
         console.error('Error loading template:', error);
         showToast(t('templates.error.load') + ': ' + error.message, 'error');
     }
 }
 
-export function closeTemplateModal() {
-    templateModal.forceClose();
-    setCurrentEditingTemplateId(null);
-    set_templateNameManuallyEdited(false);
+export async function closeTemplateModal() {
+    await templateModal.close();
 }
 
 function updateCaptureDuration(value) {
@@ -419,7 +480,7 @@ export async function saveTemplate() {
         }
 
         showToast(templateId ? t('templates.updated') : t('templates.created'), 'success');
-        closeTemplateModal();
+        templateModal.forceClose();
         await loadCaptureTemplates();
     } catch (error) {
         console.error('Error saving template:', error);
@@ -793,6 +854,7 @@ export async function showAddStreamModal(presetType, cloneData = null) {
     }
 
     streamModal.open();
+    streamModal.snapshot();
 }
 
 export async function editStream(streamId) {
@@ -837,6 +899,7 @@ export async function editStream(streamId) {
         }
 
         streamModal.open();
+        streamModal.snapshot();
     } catch (error) {
         console.error('Error loading stream:', error);
         showToast(t('streams.error.load') + ': ' + error.message, 'error');
@@ -996,7 +1059,7 @@ export async function saveStream() {
         }
 
         showToast(streamId ? t('streams.updated') : t('streams.created'), 'success');
-        closeStreamModal();
+        streamModal.forceClose();
         await loadPictureSources();
     } catch (error) {
         console.error('Error saving stream:', error);
@@ -1023,10 +1086,8 @@ export async function deleteStream(streamId) {
     }
 }
 
-export function closeStreamModal() {
-    streamModal.forceClose();
-    document.getElementById('stream-type').disabled = false;
-    set_streamNameManuallyEdited(false);
+export async function closeStreamModal() {
+    await streamModal.close();
 }
 
 async function validateStaticImage() {
@@ -1448,6 +1509,7 @@ export async function showAddPPTemplateModal(cloneData = null) {
     }
 
     ppTemplateModal.open();
+    ppTemplateModal.snapshot();
 }
 
 export async function editPPTemplate(templateId) {
@@ -1473,6 +1535,7 @@ export async function editPPTemplate(templateId) {
         renderModalFilterList();
 
         ppTemplateModal.open();
+        ppTemplateModal.snapshot();
     } catch (error) {
         console.error('Error loading PP template:', error);
         showToast(t('postprocessing.error.load') + ': ' + error.message, 'error');
@@ -1503,7 +1566,7 @@ export async function savePPTemplate() {
         }
 
         showToast(templateId ? t('postprocessing.updated') : t('postprocessing.created'), 'success');
-        closePPTemplateModal();
+        ppTemplateModal.forceClose();
         await loadPPTemplates();
     } catch (error) {
         console.error('Error saving PP template:', error);
@@ -1571,10 +1634,8 @@ export async function deletePPTemplate(templateId) {
     }
 }
 
-export function closePPTemplateModal() {
-    ppTemplateModal.forceClose();
-    set_modalFilters([]);
-    set_ppTemplateNameManuallyEdited(false);
+export async function closePPTemplateModal() {
+    await ppTemplateModal.close();
 }
 
 // Exported helpers used by other modules
diff --git a/server/src/wled_controller/static/js/features/value-sources.js b/server/src/wled_controller/static/js/features/value-sources.js
index ed70838..4326f52 100644
--- a/server/src/wled_controller/static/js/features/value-sources.js
+++ b/server/src/wled_controller/static/js/features/value-sources.js
@@ -17,7 +17,36 @@ import { showToast, showConfirm } from '../core/ui.js';
 import { Modal } from '../core/modal.js';
 import { loadPictureSources } from './streams.js';
 
-const valueSourceModal = new Modal('value-source-modal');
+class ValueSourceModal extends Modal {
+    constructor() { super('value-source-modal'); }
+
+    snapshotValues() {
+        const type = document.getElementById('value-source-type').value;
+        return {
+            name: document.getElementById('value-source-name').value,
+            description: document.getElementById('value-source-description').value,
+            type,
+            value: document.getElementById('value-source-value').value,
+            waveform: document.getElementById('value-source-waveform').value,
+            speed: document.getElementById('value-source-speed').value,
+            minValue: document.getElementById('value-source-min-value').value,
+            maxValue: document.getElementById('value-source-max-value').value,
+            audioSource: document.getElementById('value-source-audio-source').value,
+            mode: document.getElementById('value-source-mode').value,
+            sensitivity: document.getElementById('value-source-sensitivity').value,
+            smoothing: document.getElementById('value-source-smoothing').value,
+            adaptiveMin: document.getElementById('value-source-adaptive-min-value').value,
+            adaptiveMax: document.getElementById('value-source-adaptive-max-value').value,
+            pictureSource: document.getElementById('value-source-picture-source').value,
+            sceneBehavior: document.getElementById('value-source-scene-behavior').value,
+            sceneSensitivity: document.getElementById('value-source-scene-sensitivity').value,
+            sceneSmoothing: document.getElementById('value-source-scene-smoothing').value,
+            schedule: JSON.stringify(_getScheduleFromUI()),
+        };
+    }
+}
+
+const valueSourceModal = new ValueSourceModal();
 
 // ── Modal ─────────────────────────────────────────────────────
 
@@ -87,10 +116,11 @@ export async function showValueSourceModal(editData) {
     }
 
     valueSourceModal.open();
+    valueSourceModal.snapshot();
 }
 
-export function closeValueSourceModal() {
-    valueSourceModal.forceClose();
+export async function closeValueSourceModal() {
+    await valueSourceModal.close();
 }
 
 export function onValueSourceTypeChange() {