diff --git a/src/components/common/PageTransition.scss b/src/components/common/PageTransition.scss
index e0d21e8..6ff5600 100644
--- a/src/components/common/PageTransition.scss
+++ b/src/components/common/PageTransition.scss
@@ -29,6 +29,18 @@
 
     &--stacked {
       display: none;
+
+      // Keep the previous layer rendered (but invisible) to avoid a blank flash when popping back.
+      // Older stacked layers remain `display: none` for performance.
+      &.page-transition__layer--stacked-keep {
+        display: flex;
+        position: absolute;
+        inset: 0;
+        overflow: hidden;
+        pointer-events: none;
+        opacity: 0;
+        will-change: transform, opacity;
+      }
     }
   }
 
@@ -36,7 +48,7 @@
     will-change: transform, opacity;
   }
 
-  &--animating &__layer:not(.page-transition__layer--exit) {
+  &--animating &__layer:not(.page-transition__layer--exit):not(.page-transition__layer--stacked) {
     position: relative;
   }
 }
diff --git a/src/components/common/PageTransition.tsx b/src/components/common/PageTransition.tsx
index de90795..a91e59a 100644
--- a/src/components/common/PageTransition.tsx
+++ b/src/components/common/PageTransition.tsx
@@ -83,20 +83,28 @@ export function PageTransition({
     };
     const fromIndex = resolveOrderIndex(currentLayerPathname);
     const toIndex = resolveOrderIndex(location.pathname);
-    const nextDirection: TransitionDirection =
+    const nextVariant: TransitionVariant = getTransitionVariant
+      ? getTransitionVariant(currentLayerPathname ?? '', location.pathname)
+      : 'vertical';
+
+    let nextDirection: TransitionDirection =
       fromIndex === null || toIndex === null || fromIndex === toIndex
         ? 'forward'
         : toIndex > fromIndex
           ? 'forward'
           : 'backward';
 
+    // When using iOS-style stacking, history POP within the same "section" can have equal route order.
+    // In that case, prefer treating navigation to an existing layer as a backward (pop) transition.
+    if (nextVariant === 'ios' && layers.some((layer) => layer.key === location.key)) {
+      nextDirection = 'backward';
+    }
+
     transitionDirectionRef.current = nextDirection;
-    transitionVariantRef.current = getTransitionVariant
-      ? getTransitionVariant(currentLayerPathname ?? '', location.pathname)
-      : 'vertical';
+    transitionVariantRef.current = nextVariant;
 
     const shouldSkipExitLayer = (() => {
-      if (transitionVariantRef.current !== 'ios' || nextDirection !== 'backward') return false;
+      if (nextVariant !== 'ios' || nextDirection !== 'backward') return false;
       const normalizeSegments = (pathname: string) =>
         pathname
           .split('/')
@@ -178,6 +186,7 @@ export function PageTransition({
     getRouteOrder,
     getTransitionVariant,
     resolveScrollContainer,
+    layers,
   ]);
 
   // Run GSAP animation when animating starts
@@ -322,16 +331,30 @@ export function PageTransition({
 
   return (
     <div className={`page-transition${isAnimating ? ' page-transition--animating' : ''}`}>
-      {layers.map((layer) => (
+      {(() => {
+        const currentIndex = layers.findIndex((layer) => layer.status === 'current');
+        const resolvedCurrentIndex = currentIndex === -1 ? layers.length - 1 : currentIndex;
+        const keepStackedIndex = layers
+          .slice(0, resolvedCurrentIndex)
+          .map((layer, index) => ({ layer, index }))
+          .reverse()
+          .find(({ layer }) => layer.status === 'stacked')?.index;
+
+        return layers.map((layer, index) => {
+          const shouldKeepStacked = layer.status === 'stacked' && index === keepStackedIndex;
+          return (
         <div
           key={layer.key}
           className={[
             'page-transition__layer',
             layer.status === 'exiting' ? 'page-transition__layer--exit' : '',
             layer.status === 'stacked' ? 'page-transition__layer--stacked' : '',
+            shouldKeepStacked ? 'page-transition__layer--stacked-keep' : '',
           ]
             .filter(Boolean)
             .join(' ')}
+          aria-hidden={layer.status !== 'current'}
+          inert={layer.status !== 'current'}
           ref={
             layer.status === 'exiting'
               ? exitingLayerRef
@@ -342,7 +365,9 @@ export function PageTransition({
         >
           {render(layer.location)}
         </div>
-      ))}
+          );
+        });
+      })()}
     </div>
   );
 }
diff --git a/src/components/providers/ProviderNav/ProviderNav.module.scss b/src/components/providers/ProviderNav/ProviderNav.module.scss
index eafe1ab..8e8021c 100644
--- a/src/components/providers/ProviderNav/ProviderNav.module.scss
+++ b/src/components/providers/ProviderNav/ProviderNav.module.scss
@@ -75,9 +75,39 @@
   }
 }
 
-// 小屏幕隐藏悬浮导航
+// 小屏幕改为底部横向浮层
 @media (max-width: 1200px) {
   .navContainer {
-    display: none;
+    top: auto;
+    right: auto;
+    left: 50%;
+    bottom: calc(12px + env(safe-area-inset-bottom));
+    transform: translateX(-50%);
+    width: min(520px, calc(100vw - 24px));
+  }
+
+  .navList {
+    flex-direction: row;
+    gap: 6px;
+    padding: 8px 10px;
+    border-radius: 999px;
+    overflow-x: auto;
+    scrollbar-width: none;
+
+    &::-webkit-scrollbar {
+      display: none;
+    }
+  }
+
+  .navItem {
+    width: 36px;
+    height: 36px;
+    border-radius: 999px;
+    flex: 0 0 auto;
+  }
+
+  .icon {
+    width: 22px;
+    height: 22px;
   }
 }
diff --git a/src/components/providers/ProviderNav/ProviderNav.tsx b/src/components/providers/ProviderNav/ProviderNav.tsx
index d7f039e..c6d39f3 100644
--- a/src/components/providers/ProviderNav/ProviderNav.tsx
+++ b/src/components/providers/ProviderNav/ProviderNav.tsx
@@ -29,25 +29,47 @@ const PROVIDERS: ProviderNavItem[] = [
 ];
 
 const HEADER_OFFSET = 24;
+type ScrollContainer = HTMLElement | (Window & typeof globalThis);
 
 export function ProviderNav() {
   const resolvedTheme = useThemeStore((state) => state.resolvedTheme);
   const [activeProvider, setActiveProvider] = useState<ProviderId | null>(null);
-  const scrollContainerRef = useRef<HTMLElement | null>(null);
+  const contentScrollerRef = useRef<HTMLElement | null>(null);
+
+  const getHeaderHeight = useCallback(() => {
+    const header = document.querySelector('.main-header') as HTMLElement | null;
+    if (header) return header.getBoundingClientRect().height;
+
+    const raw = getComputedStyle(document.documentElement).getPropertyValue('--header-height');
+    const value = Number.parseFloat(raw);
+    return Number.isFinite(value) ? value : 0;
+  }, []);
+
+  const getContentScroller = useCallback(() => {
+    if (contentScrollerRef.current && document.contains(contentScrollerRef.current)) {
+      return contentScrollerRef.current;
+    }
 
-  const getScrollContainer = useCallback(() => {
-    if (scrollContainerRef.current) return scrollContainerRef.current;
     const container = document.querySelector('.content') as HTMLElement | null;
-    scrollContainerRef.current = container;
+    contentScrollerRef.current = container;
     return container;
   }, []);
 
+  const getScrollContainer = useCallback((): ScrollContainer => {
+    // Mobile layout uses document scroll (layout switches at 768px); desktop uses the `.content` scroller.
+    const isMobile = window.matchMedia('(max-width: 768px)').matches;
+    if (isMobile) return window;
+    return getContentScroller() ?? window;
+  }, [getContentScroller]);
+
   const handleScroll = useCallback(() => {
     const container = getScrollContainer();
     if (!container) return;
 
-    const containerRect = container.getBoundingClientRect();
-    const activationLine = containerRect.top + HEADER_OFFSET + 1;
+    const isElementScroller = container instanceof HTMLElement;
+    const headerHeight = isElementScroller ? 0 : getHeaderHeight();
+    const containerTop = isElementScroller ? container.getBoundingClientRect().top : 0;
+    const activationLine = containerTop + headerHeight + HEADER_OFFSET + 1;
     let currentActive: ProviderId | null = null;
 
     for (const provider of PROVIDERS) {
@@ -71,31 +93,44 @@ export function ProviderNav() {
     }
 
     setActiveProvider(currentActive);
-  }, [getScrollContainer]);
+  }, [getHeaderHeight, getScrollContainer]);
 
   useEffect(() => {
-    const container = getScrollContainer();
-    if (!container) return;
+    const contentScroller = getContentScroller();
 
-    container.addEventListener('scroll', handleScroll, { passive: true });
+    // Listen to both: desktop scroll happens on `.content`; mobile uses `window`.
+    window.addEventListener('scroll', handleScroll, { passive: true });
+    contentScroller?.addEventListener('scroll', handleScroll, { passive: true });
+    window.addEventListener('resize', handleScroll);
     handleScroll();
-    return () => container.removeEventListener('scroll', handleScroll);
-  }, [handleScroll, getScrollContainer]);
+    return () => {
+      window.removeEventListener('scroll', handleScroll);
+      window.removeEventListener('resize', handleScroll);
+      contentScroller?.removeEventListener('scroll', handleScroll);
+    };
+  }, [getContentScroller, handleScroll]);
 
   const scrollToProvider = (providerId: ProviderId) => {
     const container = getScrollContainer();
     const element = document.getElementById(`provider-${providerId}`);
     if (!element || !container) return;
 
+    setActiveProvider(providerId);
+
+    // Mobile: scroll the document (header is fixed, so offset by header height).
+    if (!(container instanceof HTMLElement)) {
+      const headerHeight = getHeaderHeight();
+      const elementTop = element.getBoundingClientRect().top + window.scrollY;
+      const target = Math.max(0, elementTop - headerHeight - HEADER_OFFSET);
+      window.scrollTo({ top: target, behavior: 'smooth' });
+      return;
+    }
+
     const containerRect = container.getBoundingClientRect();
     const elementRect = element.getBoundingClientRect();
     const scrollTop = container.scrollTop + (elementRect.top - containerRect.top) - HEADER_OFFSET;
 
-    setActiveProvider(providerId);
-    container.scrollTo({
-      top: scrollTop,
-      behavior: 'smooth',
-    });
+    container.scrollTo({ top: scrollTop, behavior: 'smooth' });
   };
 
   const navContent = (
diff --git a/src/pages/AiProvidersOpenAIEditLayout.tsx b/src/pages/AiProvidersOpenAIEditLayout.tsx
index 70280b1..321b0c4 100644
--- a/src/pages/AiProvidersOpenAIEditLayout.tsx
+++ b/src/pages/AiProvidersOpenAIEditLayout.tsx
@@ -3,7 +3,7 @@ import { useCallback, useEffect, useMemo, useState } from 'react';
 import { Outlet, useLocation, useNavigate, useParams } from 'react-router-dom';
 import { useTranslation } from 'react-i18next';
 import { providersApi } from '@/services/api';
-import { useAuthStore, useConfigStore, useNotificationStore } from '@/stores';
+import { useAuthStore, useConfigStore, useNotificationStore, useOpenAIEditDraftStore } from '@/stores';
 import { entriesToModels, modelsToEntries } from '@/components/ui/modelInputListUtils';
 import type { ApiKeyEntry, OpenAIProviderConfig } from '@/types';
 import type { ModelInfo } from '@/utils/models';
@@ -71,18 +71,69 @@ export function AiProvidersOpenAIEditLayout() {
   const connectionStatus = useAuthStore((state) => state.connectionStatus);
   const disableControls = connectionStatus !== 'connected';
 
+  const config = useConfigStore((state) => state.config);
   const fetchConfig = useConfigStore((state) => state.fetchConfig);
   const updateConfigValue = useConfigStore((state) => state.updateConfigValue);
   const clearCache = useConfigStore((state) => state.clearCache);
+  const isCacheValid = useConfigStore((state) => state.isCacheValid);
 
-  const [providers, setProviders] = useState<OpenAIProviderConfig[]>([]);
-  const [form, setForm] = useState<OpenAIFormState>(() => buildEmptyForm());
-  const [testModel, setTestModel] = useState('');
-  const [testStatus, setTestStatus] = useState<'idle' | 'loading' | 'success' | 'error'>('idle');
-  const [testMessage, setTestMessage] = useState('');
-  const [loading, setLoading] = useState(true);
+  const [providers, setProviders] = useState<OpenAIProviderConfig[]>(
+    () => config?.openaiCompatibility ?? []
+  );
+  const [loading, setLoading] = useState(
+    () => !isCacheValid('openai-compatibility')
+  );
   const [saving, setSaving] = useState(false);
 
+  const draftKey = useMemo(() => {
+    if (invalidIndexParam) return `openai:invalid:${params.index ?? 'unknown'}`;
+    if (editIndex === null) return 'openai:new';
+    return `openai:${editIndex}`;
+  }, [editIndex, invalidIndexParam, params.index]);
+
+  const draft = useOpenAIEditDraftStore((state) => state.drafts[draftKey]);
+  const ensureDraft = useOpenAIEditDraftStore((state) => state.ensureDraft);
+  const initDraft = useOpenAIEditDraftStore((state) => state.initDraft);
+  const clearDraft = useOpenAIEditDraftStore((state) => state.clearDraft);
+  const setDraftForm = useOpenAIEditDraftStore((state) => state.setDraftForm);
+  const setDraftTestModel = useOpenAIEditDraftStore((state) => state.setDraftTestModel);
+  const setDraftTestStatus = useOpenAIEditDraftStore((state) => state.setDraftTestStatus);
+  const setDraftTestMessage = useOpenAIEditDraftStore((state) => state.setDraftTestMessage);
+
+  const form = draft?.form ?? buildEmptyForm();
+  const testModel = draft?.testModel ?? '';
+  const testStatus = draft?.testStatus ?? 'idle';
+  const testMessage = draft?.testMessage ?? '';
+
+  const setForm: Dispatch<SetStateAction<OpenAIFormState>> = useCallback(
+    (action) => {
+      setDraftForm(draftKey, action);
+    },
+    [draftKey, setDraftForm]
+  );
+
+  const setTestModel: Dispatch<SetStateAction<string>> = useCallback(
+    (action) => {
+      setDraftTestModel(draftKey, action);
+    },
+    [draftKey, setDraftTestModel]
+  );
+
+  const setTestStatus: Dispatch<SetStateAction<'idle' | 'loading' | 'success' | 'error'>> =
+    useCallback(
+      (action) => {
+        setDraftTestStatus(draftKey, action);
+      },
+      [draftKey, setDraftTestStatus]
+    );
+
+  const setTestMessage: Dispatch<SetStateAction<string>> = useCallback(
+    (action) => {
+      setDraftTestMessage(draftKey, action);
+    },
+    [draftKey, setDraftTestMessage]
+  );
+
   const initialData = useMemo(() => {
     if (editIndex === null) return undefined;
     return providers[editIndex];
@@ -95,18 +146,26 @@ export function AiProvidersOpenAIEditLayout() {
     [form.modelEntries]
   );
 
+  useEffect(() => {
+    ensureDraft(draftKey);
+  }, [draftKey, ensureDraft]);
+
   const handleBack = useCallback(() => {
+    clearDraft(draftKey);
     const state = location.state as LocationState;
     if (state?.fromAiProviders) {
       navigate(-1);
       return;
     }
     navigate('/ai-providers', { replace: true });
-  }, [location.state, navigate]);
+  }, [clearDraft, draftKey, location.state, navigate]);
 
   useEffect(() => {
     let cancelled = false;
-    setLoading(true);
+    const hasValidCache = isCacheValid('openai-compatibility');
+    if (!hasValidCache) {
+      setLoading(true);
+    }
 
     fetchConfig('openai-compatibility')
       .then((value) => {
@@ -126,14 +185,15 @@ export function AiProvidersOpenAIEditLayout() {
     return () => {
       cancelled = true;
     };
-  }, [fetchConfig, showNotification, t]);
+  }, [fetchConfig, isCacheValid, showNotification, t]);
 
   useEffect(() => {
     if (loading) return;
+    if (draft?.initialized) return;
 
     if (initialData) {
       const modelEntries = modelsToEntries(initialData.models);
-      setForm({
+      const seededForm: OpenAIFormState = {
         name: initialData.name,
         prefix: initialData.prefix ?? '',
         baseUrl: initialData.baseUrl,
@@ -143,22 +203,28 @@ export function AiProvidersOpenAIEditLayout() {
         apiKeyEntries: initialData.apiKeyEntries?.length
           ? initialData.apiKeyEntries
           : [buildApiKeyEntry()],
-      });
+      };
 
       const available = modelEntries.map((entry) => entry.name.trim()).filter(Boolean);
       const initialTestModel =
         initialData.testModel && available.includes(initialData.testModel)
           ? initialData.testModel
           : available[0] || '';
-      setTestModel(initialTestModel);
+      initDraft(draftKey, {
+        form: seededForm,
+        testModel: initialTestModel,
+        testStatus: 'idle',
+        testMessage: '',
+      });
     } else {
-      setForm(buildEmptyForm());
-      setTestModel('');
+      initDraft(draftKey, {
+        form: buildEmptyForm(),
+        testModel: '',
+        testStatus: 'idle',
+        testMessage: '',
+      });
     }
-
-    setTestStatus('idle');
-    setTestMessage('');
-  }, [initialData, loading]);
+  }, [draft?.initialized, draftKey, initDraft, initialData, loading]);
 
   useEffect(() => {
     if (loading) return;
@@ -183,32 +249,34 @@ export function AiProvidersOpenAIEditLayout() {
     (selectedModels: ModelInfo[]) => {
       if (!selectedModels.length) return;
 
-      const mergedMap = new Map<string, ModelEntry>();
-      form.modelEntries.forEach((entry) => {
-        const name = entry.name.trim();
-        if (!name) return;
-        mergedMap.set(name, { name, alias: entry.alias?.trim() || '' });
-      });
-
       let addedCount = 0;
-      selectedModels.forEach((model) => {
-        const name = model.name.trim();
-        if (!name || mergedMap.has(name)) return;
-        mergedMap.set(name, { name, alias: model.alias ?? '' });
-        addedCount += 1;
-      });
+      setForm((prev) => {
+        const mergedMap = new Map<string, ModelEntry>();
+        prev.modelEntries.forEach((entry) => {
+          const name = entry.name.trim();
+          if (!name) return;
+          mergedMap.set(name, { name, alias: entry.alias?.trim() || '' });
+        });
 
-      const mergedEntries = Array.from(mergedMap.values());
-      setForm((prev) => ({
-        ...prev,
-        modelEntries: mergedEntries.length ? mergedEntries : [{ name: '', alias: '' }],
-      }));
+        selectedModels.forEach((model) => {
+          const name = model.name.trim();
+          if (!name || mergedMap.has(name)) return;
+          mergedMap.set(name, { name, alias: model.alias ?? '' });
+          addedCount += 1;
+        });
+
+        const mergedEntries = Array.from(mergedMap.values());
+        return {
+          ...prev,
+          modelEntries: mergedEntries.length ? mergedEntries : [{ name: '', alias: '' }],
+        };
+      });
 
       if (addedCount > 0) {
         showNotification(t('ai_providers.openai_models_fetch_added', { count: addedCount }), 'success');
       }
     },
-    [form.modelEntries, showNotification, t]
+    [setForm, showNotification, t]
   );
 
   const handleSave = useCallback(async () => {
@@ -225,7 +293,8 @@ export function AiProvidersOpenAIEditLayout() {
           headers: entry.headers,
         })),
       };
-      if (form.testModel) payload.testModel = form.testModel.trim();
+      const resolvedTestModel = testModel.trim();
+      if (resolvedTestModel) payload.testModel = resolvedTestModel;
       const models = entriesToModels(form.modelEntries);
       if (models.length) payload.models = models;
 
@@ -256,11 +325,14 @@ export function AiProvidersOpenAIEditLayout() {
     form,
     handleBack,
     providers,
+    testModel,
     showNotification,
     t,
     updateConfigValue,
   ]);
 
+  const resolvedLoading = !draft?.initialized;
+
   return (
     <Outlet
       context={{
@@ -269,7 +341,7 @@ export function AiProvidersOpenAIEditLayout() {
         invalidIndexParam,
         invalidIndex,
         disableControls,
-        loading,
+        loading: resolvedLoading,
         saving,
         form,
         setForm,
diff --git a/src/pages/AiProvidersPage.module.scss b/src/pages/AiProvidersPage.module.scss
index eff7935..78f4195 100644
--- a/src/pages/AiProvidersPage.module.scss
+++ b/src/pages/AiProvidersPage.module.scss
@@ -27,6 +27,10 @@
   display: flex;
   flex-direction: column;
   gap: $spacing-xl;
+
+  @include mobile {
+    padding-bottom: calc(72px + env(safe-area-inset-bottom));
+  }
 }
 
 .section {
diff --git a/src/pages/LoginPage.tsx b/src/pages/LoginPage.tsx
index f8953c7..255af84 100644
--- a/src/pages/LoginPage.tsx
+++ b/src/pages/LoginPage.tsx
@@ -90,7 +90,7 @@ export function LoginPage() {
           setTimeout(() => {
             const redirect = (location.state as any)?.from?.pathname || '/';
             navigate(redirect, { replace: true });
-          }, 1300);
+          }, 1500);
         } else {
           setApiBase(storedBase || detectedBase);
           setManagementKey(storedKey || '');
diff --git a/src/stores/index.ts b/src/stores/index.ts
index 7432fe0..797a67e 100644
--- a/src/stores/index.ts
+++ b/src/stores/index.ts
@@ -9,3 +9,4 @@ export { useAuthStore } from './useAuthStore';
 export { useConfigStore } from './useConfigStore';
 export { useModelsStore } from './useModelsStore';
 export { useQuotaStore } from './useQuotaStore';
+export { useOpenAIEditDraftStore } from './useOpenAIEditDraftStore';
diff --git a/src/stores/useOpenAIEditDraftStore.ts b/src/stores/useOpenAIEditDraftStore.ts
new file mode 100644
index 0000000..bab02d4
--- /dev/null
+++ b/src/stores/useOpenAIEditDraftStore.ts
@@ -0,0 +1,148 @@
+/**
+ * OpenAI provider editor draft state.
+ *
+ * Why this exists:
+ * - The app uses `PageTransition` with iOS-style stacked routes for `/ai-providers/*`.
+ * - Entering `/ai-providers/openai/.../models` creates a new route layer, so component-local state
+ *   inside the OpenAI edit layout is not shared between the edit screen and the model picker screen.
+ * - This store makes the OpenAI edit draft shared across route layers keyed by provider index/new.
+ */
+
+import type { SetStateAction } from 'react';
+import { create } from 'zustand';
+import type { OpenAIFormState } from '@/components/providers/types';
+import { buildApiKeyEntry } from '@/components/providers/utils';
+
+export type OpenAITestStatus = 'idle' | 'loading' | 'success' | 'error';
+
+export type OpenAIEditDraft = {
+  initialized: boolean;
+  form: OpenAIFormState;
+  testModel: string;
+  testStatus: OpenAITestStatus;
+  testMessage: string;
+};
+
+interface OpenAIEditDraftState {
+  drafts: Record<string, OpenAIEditDraft>;
+  ensureDraft: (key: string) => void;
+  initDraft: (key: string, draft: Omit<OpenAIEditDraft, 'initialized'>) => void;
+  setDraftForm: (key: string, action: SetStateAction<OpenAIFormState>) => void;
+  setDraftTestModel: (key: string, action: SetStateAction<string>) => void;
+  setDraftTestStatus: (key: string, action: SetStateAction<OpenAITestStatus>) => void;
+  setDraftTestMessage: (key: string, action: SetStateAction<string>) => void;
+  clearDraft: (key: string) => void;
+}
+
+const resolveAction = <T,>(action: SetStateAction<T>, prev: T): T =>
+  typeof action === 'function' ? (action as (previous: T) => T)(prev) : action;
+
+const buildEmptyForm = (): OpenAIFormState => ({
+  name: '',
+  prefix: '',
+  baseUrl: '',
+  headers: [],
+  apiKeyEntries: [buildApiKeyEntry()],
+  modelEntries: [{ name: '', alias: '' }],
+  testModel: undefined,
+});
+
+const buildEmptyDraft = (): OpenAIEditDraft => ({
+  initialized: false,
+  form: buildEmptyForm(),
+  testModel: '',
+  testStatus: 'idle',
+  testMessage: '',
+});
+
+export const useOpenAIEditDraftStore = create<OpenAIEditDraftState>((set, get) => ({
+  drafts: {},
+
+  ensureDraft: (key) => {
+    if (!key) return;
+    const existing = get().drafts[key];
+    if (existing) return;
+    set((state) => ({
+      drafts: { ...state.drafts, [key]: buildEmptyDraft() },
+    }));
+  },
+
+  initDraft: (key, draft) => {
+    if (!key) return;
+    const existing = get().drafts[key];
+    if (existing?.initialized) return;
+    set((state) => ({
+      drafts: {
+        ...state.drafts,
+        [key]: { ...draft, initialized: true },
+      },
+    }));
+  },
+
+  setDraftForm: (key, action) => {
+    if (!key) return;
+    set((state) => {
+      const existing = state.drafts[key] ?? buildEmptyDraft();
+      const nextForm = resolveAction(action, existing.form);
+      return {
+        drafts: {
+          ...state.drafts,
+          [key]: { ...existing, initialized: true, form: nextForm },
+        },
+      };
+    });
+  },
+
+  setDraftTestModel: (key, action) => {
+    if (!key) return;
+    set((state) => {
+      const existing = state.drafts[key] ?? buildEmptyDraft();
+      const nextValue = resolveAction(action, existing.testModel);
+      return {
+        drafts: {
+          ...state.drafts,
+          [key]: { ...existing, initialized: true, testModel: nextValue },
+        },
+      };
+    });
+  },
+
+  setDraftTestStatus: (key, action) => {
+    if (!key) return;
+    set((state) => {
+      const existing = state.drafts[key] ?? buildEmptyDraft();
+      const nextValue = resolveAction(action, existing.testStatus);
+      return {
+        drafts: {
+          ...state.drafts,
+          [key]: { ...existing, initialized: true, testStatus: nextValue },
+        },
+      };
+    });
+  },
+
+  setDraftTestMessage: (key, action) => {
+    if (!key) return;
+    set((state) => {
+      const existing = state.drafts[key] ?? buildEmptyDraft();
+      const nextValue = resolveAction(action, existing.testMessage);
+      return {
+        drafts: {
+          ...state.drafts,
+          [key]: { ...existing, initialized: true, testMessage: nextValue },
+        },
+      };
+    });
+  },
+
+  clearDraft: (key) => {
+    if (!key) return;
+    set((state) => {
+      if (!state.drafts[key]) return state;
+      const next = { ...state.drafts };
+      delete next[key];
+      return { drafts: next };
+    });
+  },
+}));
+