diff --git a/app/[locale]/page.tsx b/app/[locale]/page.tsx
index b89c7a40..4997abef 100644
--- a/app/[locale]/page.tsx
+++ b/app/[locale]/page.tsx
@@ -116,6 +116,7 @@ export default function Home() {
     markAsRead,
     toggleStar,
     moveToMailbox,
+    moveThreadToMailbox,
     searchEmails,
     searchQuery,
     setSearchQuery,
@@ -604,8 +605,8 @@ export default function Home() {
     }
   };
 
-  const handleArchive = async () => {
-    if (!client || !selectedEmail) return;
+  const handleArchive = async (emailToArchive: Email | null = selectedEmail) => {
+    if (!client || !emailToArchive) return;
 
     // Find archive mailbox
     const archiveMailbox = mailboxes.find(m => m.role === "archive" || m.name.toLowerCase() === "archive");
@@ -615,10 +616,10 @@ export default function Home() {
 
     try {
       if (archiveMode === 'single') {
-        await moveToMailbox(client, selectedEmail.id, archiveMailbox.id);
+        await moveThreadToMailbox(client, emailToArchive.id, archiveMailbox.id);
       } else {
         // Determine year/month from the email's received date
-        const emailDate = new Date(selectedEmail.receivedAt);
+        const emailDate = new Date(emailToArchive.receivedAt);
         const year = emailDate.getFullYear().toString();
         const month = (emailDate.getMonth() + 1).toString().padStart(2, '0');
         const archiveId = archiveMailbox.originalId || archiveMailbox.id;
@@ -633,7 +634,7 @@ export default function Home() {
         }
 
         if (archiveMode === 'year') {
-          await moveToMailbox(client, selectedEmail.id, yearMailbox.id);
+          await moveThreadToMailbox(client, emailToArchive.id, yearMailbox.id);
         } else {
           // archiveMode === 'month' — find or create month subfolder under year
           const yearId = yearMailbox.originalId || yearMailbox.id;
@@ -644,9 +645,16 @@ export default function Home() {
             monthMailbox = await client.createMailbox(month, yearId);
             await fetchMailboxes(client);
           }
-          await moveToMailbox(client, selectedEmail.id, monthMailbox.id);
+          await moveThreadToMailbox(client, emailToArchive.id, monthMailbox.id);
         }
       }
+
+      if (conversationThread?.threadId === emailToArchive.threadId) {
+        setConversationThread(null);
+        setConversationEmails([]);
+      }
+
+      void fetchMailboxes(client);
     } catch (error) {
       console.error("Failed to archive email:", error);
     }
@@ -1453,8 +1461,7 @@ export default function Home() {
                   await handleDelete();
                 }}
                 onArchive={async (email) => {
-                  selectEmail(email);
-                  await handleArchive();
+                  await handleArchive(email);
                 }}
                 onSetColorTag={(emailId, color) => {
                   handleSetColorTag(emailId, color);
diff --git a/components/settings/themes-settings.tsx b/components/settings/themes-settings.tsx
index 40eb3043..6eec790d 100644
--- a/components/settings/themes-settings.tsx
+++ b/components/settings/themes-settings.tsx
@@ -14,24 +14,31 @@ export function ThemesSettings() {
   const { installedThemes, activeThemeId, installTheme, uninstallTheme, activateTheme } = useThemeStore();
   const [isUploading, setIsUploading] = useState(false);
   const fileInputRef = useRef<HTMLInputElement>(null);
-  const { isFeatureEnabled, isThemeDisabled, getThemePolicy, isThemeForceEnabled } = usePolicyStore();
+  const { isFeatureEnabled, isThemeDisabled, getThemePolicy, getForcedThemeId, isThemeForceEnabled } = usePolicyStore();
   const canUpload = isFeatureEnabled('userThemesEnabled');
   const themePolicy = getThemePolicy();
+  const forcedThemeId = getForcedThemeId(installedThemes.map((theme) => theme.id));
 
   // Filter out themes disabled by admin policy
   const visibleThemes = installedThemes.filter(
     theme => !isThemeDisabled(theme.id, !!theme.builtIn)
   );
 
+  useEffect(() => {
+    if (forcedThemeId && activeThemeId !== forcedThemeId) {
+      activateTheme(forcedThemeId);
+    }
+  }, [activeThemeId, activateTheme, forcedThemeId]);
+
   // If the active theme was disabled by admin, fall back to default
   useEffect(() => {
     if (activeThemeId) {
       const activeTheme = installedThemes.find(t => t.id === activeThemeId);
       if (activeTheme && isThemeDisabled(activeThemeId, !!activeTheme.builtIn)) {
-        activateTheme(null);
+        activateTheme(forcedThemeId ?? null);
       }
     }
-  }, [activeThemeId, installedThemes, isThemeDisabled, activateTheme]);
+  }, [activeThemeId, activateTheme, forcedThemeId, installedThemes, isThemeDisabled]);
 
   const handleUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {
     const file = e.target.files?.[0];
@@ -58,12 +65,23 @@ export function ThemesSettings() {
   };
 
   const handleActivate = (id: string | null) => {
+    if (forcedThemeId && id !== forcedThemeId) {
+      const forcedTheme = installedThemes.find((theme) => theme.id === forcedThemeId);
+      toast.info(`Theme "${forcedTheme?.name ?? 'Admin theme'}" is forced by admin and cannot be changed`);
+      return;
+    }
+
     activateTheme(id);
     toast.success(id ? 'Theme activated' : 'Default theme restored');
   };
 
   const handleUninstall = (theme: InstalledTheme) => {
     if (theme.builtIn) return;
+    if (theme.id === forcedThemeId || theme.forceEnabled || isThemeForceEnabled(theme.id)) {
+      toast.info(`Theme "${theme.name}" is forced by admin and cannot be removed`);
+      return;
+    }
+
     uninstallTheme(theme.id);
     toast.success('Theme removed');
   };
@@ -71,6 +89,12 @@ export function ThemesSettings() {
   return (
     <SettingsSection title="Themes" description="Customize the appearance with color themes. Upload .zip theme files or activate built-in presets." experimental experimentalDescription="Themes is an experimental feature. Custom themes may not cover all UI elements, and theme formats could change in future updates. Built-in presets are stable, but uploaded themes may require updates after application upgrades.">
 
+      {forcedThemeId && (
+        <div className="mb-4 rounded-lg border border-amber-200 bg-amber-50 px-3 py-2 text-xs text-amber-800 dark:border-amber-900/40 dark:bg-amber-950/20 dark:text-amber-300">
+          Theme selection is locked by an administrator.
+        </div>
+      )}
+
       {/* Theme Grid */}
       <div className="grid grid-cols-2 sm:grid-cols-3 gap-3">
         {/* Default theme card */}
@@ -80,25 +104,30 @@ export function ThemesSettings() {
           isActive={activeThemeId === null}
           isBuiltIn
           isDefault={!themePolicy.defaultThemeId}
+          disabled={Boolean(forcedThemeId)}
           onActivate={() => handleActivate(null)}
         />
 
         {/* Installed themes */}
-        {visibleThemes.map(theme => (
-          <ThemeCard
-            key={theme.id}
-            name={theme.name}
-            author={theme.author}
-            preview={theme.preview}
-            isActive={activeThemeId === theme.id}
-            isBuiltIn={theme.builtIn}
-            isDefault={themePolicy.defaultThemeId === theme.id}
-            isForceEnabled={isThemeForceEnabled(theme.id)}
-            variants={theme.variants}
-            onActivate={() => handleActivate(theme.id)}
-            onRemove={!theme.builtIn ? () => handleUninstall(theme) : undefined}
-          />
-        ))}
+        {visibleThemes.map(theme => {
+          const isForceEnabled = theme.id === forcedThemeId || theme.forceEnabled || isThemeForceEnabled(theme.id);
+          return (
+            <ThemeCard
+              key={theme.id}
+              name={theme.name}
+              author={theme.author}
+              preview={theme.preview}
+              isActive={activeThemeId === theme.id}
+              isBuiltIn={theme.builtIn}
+              isDefault={themePolicy.defaultThemeId === theme.id}
+              isForceEnabled={isForceEnabled}
+              disabled={Boolean(forcedThemeId) && !isForceEnabled}
+              variants={theme.variants}
+              onActivate={() => handleActivate(theme.id)}
+              onRemove={!theme.builtIn && !isForceEnabled ? () => handleUninstall(theme) : undefined}
+            />
+          );
+        })}
       </div>
 
       {/* Upload */}
@@ -137,20 +166,23 @@ interface ThemeCardProps {
   isBuiltIn: boolean;
   isDefault?: boolean;
   isForceEnabled?: boolean;
+  disabled?: boolean;
   variants?: ('light' | 'dark')[];
   onActivate: () => void;
   onRemove?: () => void;
 }
 
-function ThemeCard({ name, author, preview, isActive, isDefault, isForceEnabled, variants, onActivate, onRemove }: ThemeCardProps) {
+function ThemeCard({ name, author, preview, isActive, isDefault, isForceEnabled, disabled, variants, onActivate, onRemove }: ThemeCardProps) {
   return (
     <button
       onClick={onActivate}
+      disabled={disabled}
       className={cn(
-        'relative flex flex-col items-center p-3 rounded-xl border-2 transition-all text-left w-full',
+        'relative flex flex-col items-center p-3 rounded-xl border-2 transition-all text-left w-full disabled:cursor-not-allowed disabled:opacity-60',
         isActive
           ? 'border-primary bg-primary/5 ring-1 ring-primary/20'
-          : 'border-border hover:border-primary/40 bg-card'
+          : 'border-border hover:border-primary/40 bg-card',
+        disabled && !isActive && 'hover:border-border'
       )}
     >
       {/* Preview / Placeholder */}
diff --git a/lib/jmap/client-interface.ts b/lib/jmap/client-interface.ts
index 8537e880..668eb5a5 100644
--- a/lib/jmap/client-interface.ts
+++ b/lib/jmap/client-interface.ts
@@ -80,7 +80,7 @@ export interface IJMAPClient {
   deleteEmail(emailId: string): Promise<void>;
   moveToTrash(emailId: string, trashMailboxId: string, accountId?: string): Promise<void>;
   batchDeleteEmails(emailIds: string[]): Promise<void>;
-  batchMoveEmails(emailIds: string[], toMailboxId: string): Promise<void>;
+  batchMoveEmails(emailIds: string[], toMailboxId: string, accountId?: string): Promise<void>;
   moveEmail(emailId: string, toMailboxId: string, accountId?: string): Promise<void>;
   emptyMailbox(mailboxId: string): Promise<number>;
   markAsSpam(emailId: string, accountId?: string): Promise<void>;
diff --git a/lib/jmap/client.ts b/lib/jmap/client.ts
index a1975a3c..85849e48 100644
--- a/lib/jmap/client.ts
+++ b/lib/jmap/client.ts
@@ -980,12 +980,12 @@ export class JMAPClient implements IJMAPClient {
     ]);
   }
 
-  async batchMoveEmails(emailIds: string[], toMailboxId: string): Promise<void> {
+  async batchMoveEmails(emailIds: string[], toMailboxId: string, accountId?: string): Promise<void> {
     if (emailIds.length === 0) return;
 
     const updates = Object.fromEntries(emailIds.map(id => [id, { mailboxIds: { [toMailboxId]: true } }]));
     await this.request([
-      ["Email/set", { accountId: this.accountId, update: updates }, "0"],
+      ["Email/set", { accountId: accountId || this.accountId, update: updates }, "0"],
     ]);
   }
 
diff --git a/lib/plugin-types.ts b/lib/plugin-types.ts
index 06456def..0335e2a6 100644
--- a/lib/plugin-types.ts
+++ b/lib/plugin-types.ts
@@ -59,6 +59,8 @@ export interface InstalledTheme {
   variants: ThemeVariant[];
   enabled: boolean;
   builtIn: boolean;
+  managed?: boolean;
+  forceEnabled?: boolean;
 }
 
 export interface InstalledPlugin {
diff --git a/stores/__tests__/email-archive.test.ts b/stores/__tests__/email-archive.test.ts
new file mode 100644
index 00000000..2522b58a
--- /dev/null
+++ b/stores/__tests__/email-archive.test.ts
@@ -0,0 +1,89 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { useEmailStore } from '../email-store';
+import type { Email, Mailbox } from '@/lib/jmap/types';
+import type { IJMAPClient } from '@/lib/jmap/client-interface';
+
+function makeMailbox(overrides: Partial<Mailbox> = {}): Mailbox {
+  return {
+    id: overrides.id ?? 'inbox',
+    name: overrides.name ?? 'Inbox',
+    sortOrder: 0,
+    totalEmails: 0,
+    unreadEmails: 0,
+    totalThreads: 0,
+    unreadThreads: 0,
+    myRights: {
+      mayReadItems: true,
+      mayAddItems: true,
+      mayRemoveItems: true,
+      maySetSeen: true,
+      maySetKeywords: true,
+      mayCreateChild: true,
+      mayRename: true,
+      mayDelete: true,
+      maySubmit: true,
+    },
+    isSubscribed: true,
+    isShared: false,
+    ...overrides,
+  };
+}
+
+function makeEmail(id: string, threadId: string, mailboxId = 'inbox'): Email {
+  return {
+    id,
+    threadId,
+    mailboxIds: { [mailboxId]: true },
+    keywords: {},
+    size: 100,
+    receivedAt: new Date().toISOString(),
+    from: [{ name: 'Test', email: 'test@example.com' }],
+    to: [{ name: 'User', email: 'user@example.com' }],
+    subject: `Email ${id}`,
+    preview: 'preview',
+    hasAttachment: false,
+    textBody: [],
+    htmlBody: [],
+    bodyValues: {},
+  };
+}
+
+describe('email-store archive thread behavior', () => {
+  beforeEach(() => {
+    const inbox = makeMailbox({ id: 'shared-inbox', role: 'inbox', isShared: true, accountId: 'shared-account', originalId: 'server-inbox' });
+    const archive = makeMailbox({ id: 'archive-local', role: 'archive', accountId: 'shared-account', originalId: 'server-archive' });
+    const threadEmailA = makeEmail('email-1', 'thread-1', 'shared-inbox');
+    const threadEmailB = makeEmail('email-2', 'thread-1', 'shared-inbox');
+    const otherEmail = makeEmail('email-3', 'thread-2', 'shared-inbox');
+
+    useEmailStore.setState({
+      emails: [threadEmailA, threadEmailB, otherEmail],
+      mailboxes: [inbox, archive],
+      selectedMailbox: 'shared-inbox',
+      selectedEmail: threadEmailA,
+      selectedEmailIds: new Set(['email-1', 'email-2']),
+      expandedThreadIds: new Set(['thread-1']),
+      threadEmailsCache: new Map([['thread-1', [threadEmailA, threadEmailB]]]),
+      error: null,
+    });
+  });
+
+  it('archives the full thread and removes cached thread state', async () => {
+    const client = {
+      getThread: vi.fn().mockResolvedValue({ id: 'thread-1', emailIds: ['email-1', 'email-2'] }),
+      batchMoveEmails: vi.fn().mockResolvedValue(undefined),
+    } as unknown as IJMAPClient;
+
+    await useEmailStore.getState().moveThreadToMailbox(client, 'email-1', 'archive-local');
+
+    expect(client.getThread).toHaveBeenCalledWith('thread-1', 'shared-account');
+    expect(client.batchMoveEmails).toHaveBeenCalledWith(['email-1', 'email-2'], 'server-archive', 'shared-account');
+
+    const state = useEmailStore.getState();
+    expect(state.emails.map(email => email.id)).toEqual(['email-3']);
+    expect(state.selectedEmail?.id).toBe('email-3');
+    expect(Array.from(state.selectedEmailIds)).toEqual([]);
+    expect(state.expandedThreadIds.has('thread-1')).toBe(false);
+    expect(state.threadEmailsCache.has('thread-1')).toBe(false);
+  });
+});
\ No newline at end of file
diff --git a/stores/email-store.ts b/stores/email-store.ts
index d347c6c4..a3473135 100644
--- a/stores/email-store.ts
+++ b/stores/email-store.ts
@@ -67,6 +67,7 @@ interface EmailStore {
   deleteEmail: (client: IJMAPClient, emailId: string, forceDelete?: boolean) => Promise<void>;
   markAsRead: (client: IJMAPClient, emailId: string, read: boolean) => Promise<void>;
   moveToMailbox: (client: IJMAPClient, emailId: string, mailboxId: string) => Promise<void>;
+  moveThreadToMailbox: (client: IJMAPClient, emailId: string, mailboxId: string) => Promise<void>;
   searchEmails: (client: IJMAPClient, query: string) => Promise<void>;
   advancedSearch: (client: IJMAPClient) => Promise<void>;
   setSearchFilters: (filters: Partial<SearchFilters>) => void;
@@ -111,16 +112,35 @@ interface EmailStore {
 }
 
 // Helper: compute the next email to select when removing one from the list
-function getNextSelectedEmail(state: { emails: Email[]; selectedEmail: Email | null }, removedEmailId: string): Email | null {
-  if (state.selectedEmail?.id !== removedEmailId) return state.selectedEmail;
-  const idx = state.emails.findIndex(e => e.id === removedEmailId);
+function getNextSelectedEmailAfterRemoval(state: { emails: Email[]; selectedEmail: Email | null }, removedEmailIds: Set<string>): Email | null {
+  if (!state.selectedEmail || !removedEmailIds.has(state.selectedEmail.id)) {
+    return state.selectedEmail;
+  }
+
+  const idx = state.emails.findIndex(e => e.id === state.selectedEmail?.id);
   if (idx === -1) return null;
-  // Prefer next email, fall back to previous
-  if (idx < state.emails.length - 1) return state.emails[idx + 1];
-  if (idx > 0) return state.emails[idx - 1];
+
+  for (let nextIndex = idx + 1; nextIndex < state.emails.length; nextIndex++) {
+    const candidate = state.emails[nextIndex];
+    if (!removedEmailIds.has(candidate.id)) {
+      return candidate;
+    }
+  }
+
+  for (let prevIndex = idx - 1; prevIndex >= 0; prevIndex--) {
+    const candidate = state.emails[prevIndex];
+    if (!removedEmailIds.has(candidate.id)) {
+      return candidate;
+    }
+  }
+
   return null;
 }
 
+function getNextSelectedEmail(state: { emails: Email[]; selectedEmail: Email | null }, removedEmailId: string): Email | null {
+  return getNextSelectedEmailAfterRemoval(state, new Set([removedEmailId]));
+}
+
 export const useEmailStore = create<EmailStore>((set, get) => ({
   emails: [],
   mailboxes: [],
@@ -703,6 +723,59 @@ export const useEmailStore = create<EmailStore>((set, get) => ({
     }
   },
 
+  moveThreadToMailbox: async (client, emailId, destinationMailboxId) => {
+    try {
+      const state = get();
+      const email = state.emails.find(e => e.id === emailId)
+        ?? (state.selectedEmail?.id === emailId ? state.selectedEmail : null);
+
+      if (!email?.threadId) {
+        await get().moveToMailbox(client, emailId, destinationMailboxId);
+        return;
+      }
+
+      const currentMailbox = state.mailboxes.find(mb => mb.id === state.selectedMailbox);
+      const accountId = currentMailbox?.isShared ? currentMailbox.accountId : undefined;
+      const destMailbox = state.mailboxes.find(mb => mb.id === destinationMailboxId);
+      const jmapDestId = destMailbox?.originalId || destinationMailboxId;
+
+      const thread = await client.getThread(email.threadId, accountId);
+      const threadEmailIds = thread?.emailIds?.length ? thread.emailIds : [emailId];
+
+      if (threadEmailIds.length <= 1) {
+        await get().moveToMailbox(client, emailId, destinationMailboxId);
+        return;
+      }
+
+      await client.batchMoveEmails(threadEmailIds, jmapDestId, accountId);
+
+      const removedEmailIds = new Set(threadEmailIds);
+      set((currentState) => {
+        const nextSelectedEmail = getNextSelectedEmailAfterRemoval(currentState, removedEmailIds);
+        const nextSelectedEmailIds = new Set(
+          Array.from(currentState.selectedEmailIds).filter(id => !removedEmailIds.has(id))
+        );
+        const nextExpandedThreadIds = new Set(currentState.expandedThreadIds);
+        nextExpandedThreadIds.delete(email.threadId);
+        const nextThreadEmailsCache = new Map(currentState.threadEmailsCache);
+        nextThreadEmailsCache.delete(email.threadId);
+
+        return {
+          emails: currentState.emails.filter(currentEmail => !removedEmailIds.has(currentEmail.id)),
+          selectedEmail: nextSelectedEmail,
+          selectedEmailIds: nextSelectedEmailIds,
+          expandedThreadIds: nextExpandedThreadIds,
+          threadEmailsCache: nextThreadEmailsCache,
+        };
+      });
+    } catch (error) {
+      set({
+        error: error instanceof Error ? error.message : "Failed to move email thread"
+      });
+      throw error;
+    }
+  },
+
   searchEmails: async (client, query) => {
     set({ isLoading: true, error: null, searchQuery: query, emails: [], hasMoreEmails: false, totalEmails: 0 }); // Clear emails for loading state
     try {
diff --git a/stores/policy-store.ts b/stores/policy-store.ts
index f98cab79..fe2c5d13 100644
--- a/stores/policy-store.ts
+++ b/stores/policy-store.ts
@@ -12,6 +12,7 @@ interface PolicyState {
   getRestriction: (key: string) => SettingRestriction | undefined;
   getEffectiveDefault: (key: string) => unknown;
   getThemePolicy: () => ThemePolicy;
+  getForcedThemeId: (availableThemeIds?: string[]) => string | null;
   isThemeDisabled: (themeId: string, isBuiltIn: boolean) => boolean;
   isPluginForceEnabled: (pluginId: string) => boolean;
   isThemeForceEnabled: (themeId: string) => boolean;
@@ -61,6 +62,16 @@ export const usePolicyStore = create<PolicyState>()((set, get) => ({
     return get().policy.themePolicy || { ...DEFAULT_THEME_POLICY };
   },
 
+  getForcedThemeId: (availableThemeIds) => {
+    const forceEnabledThemes = get().policy.forceEnabledThemes || [];
+    if (!availableThemeIds || availableThemeIds.length === 0) {
+      return forceEnabledThemes[0] || null;
+    }
+
+    const available = new Set(availableThemeIds);
+    return forceEnabledThemes.find((themeId) => available.has(themeId)) || null;
+  },
+
   isThemeDisabled: (themeId, isBuiltIn) => {
     const tp = get().policy.themePolicy || DEFAULT_THEME_POLICY;
     if (isBuiltIn) {
diff --git a/stores/theme-store.ts b/stores/theme-store.ts
index ec3937b7..3ec62b26 100644
--- a/stores/theme-store.ts
+++ b/stores/theme-store.ts
@@ -9,6 +9,18 @@ import { usePolicyStore } from '@/stores/policy-store';
 
 type Theme = 'light' | 'dark' | 'system';
 
+function getForcedThemeId(installedThemes: InstalledTheme[]): string | null {
+  const policyForcedThemeId = usePolicyStore
+    .getState()
+    .getForcedThemeId(installedThemes.map((theme) => theme.id));
+
+  if (policyForcedThemeId) {
+    return policyForcedThemeId;
+  }
+
+  return installedThemes.find((theme) => theme.forceEnabled)?.id ?? null;
+}
+
 interface ThemeState {
   theme: Theme;
   resolvedTheme: 'light' | 'dark';
@@ -90,18 +102,21 @@ export const useThemeStore = create<ThemeState>()(
         applyTheme(resolvedTheme);
         set({ resolvedTheme, hydrated: true });
 
-        // Determine effective theme: user choice > policy default > none
-        let effectiveThemeId = activeThemeId;
+        // Determine effective theme: forced theme > user choice > policy default > none
+        const forcedThemeId = getForcedThemeId(installedThemes);
+        let effectiveThemeId = forcedThemeId ?? activeThemeId;
         if (!effectiveThemeId) {
           const policyState = usePolicyStore.getState();
           const tp = policyState.policy.themePolicy;
           if (tp?.defaultThemeId) {
             effectiveThemeId = tp.defaultThemeId;
-            // Persist so we don't re-check every time
-            set({ activeThemeId: effectiveThemeId });
           }
         }
 
+        if (effectiveThemeId !== activeThemeId) {
+          set({ activeThemeId: effectiveThemeId });
+        }
+
         // Apply active custom theme on boot
         if (effectiveThemeId) {
           const t = installedThemes.find(t => t.id === effectiveThemeId);
@@ -215,6 +230,8 @@ export const useThemeStore = create<ThemeState>()(
         const { installedThemes, activeThemeId } = get();
         const theme = installedThemes.find(t => t.id === id);
         if (!theme || theme.builtIn) return;
+        const forceEnabledByPolicy = usePolicyStore.getState().isThemeForceEnabled(id);
+        if (theme.forceEnabled || forceEnabledByPolicy) return;
 
         // Deactivate if active
         if (activeThemeId === id) {
@@ -232,16 +249,44 @@ export const useThemeStore = create<ThemeState>()(
       },
 
       activateTheme: (id: string | null) => {
+        const { installedThemes, resolvedTheme } = get();
+        const forcedThemeId = getForcedThemeId(installedThemes);
+
+        if (forcedThemeId && id !== forcedThemeId) {
+          const forcedTheme = installedThemes.find((theme) => theme.id === forcedThemeId);
+          if (forcedTheme) {
+            applyCustomThemeCSS(forcedTheme, resolvedTheme);
+            set({ activeThemeId: forcedThemeId });
+          }
+          return;
+        }
+
         if (id === null) {
           removeThemeCSS();
           set({ activeThemeId: null });
           return;
         }
 
-        const { installedThemes, resolvedTheme } = get();
         const theme = installedThemes.find(t => t.id === id);
         if (!theme) return;
 
+        if (!theme.css) {
+          pluginStorage.getThemeCSS(id).then((css) => {
+            if (!css) return;
+
+            const hydratedTheme = { ...theme, css };
+            applyCustomThemeCSS(hydratedTheme, get().resolvedTheme);
+            set((state) => ({
+              activeThemeId: id,
+              installedThemes: state.installedThemes.map((item) =>
+                item.id === id ? { ...item, css } : item
+              ),
+            }));
+          });
+          set({ activeThemeId: id });
+          return;
+        }
+
         applyCustomThemeCSS(theme, resolvedTheme);
         set({ activeThemeId: id });
       },
@@ -281,6 +326,8 @@ export const useThemeStore = create<ThemeState>()(
                   variants: st.variants as ThemeVariant[],
                   enabled: true,
                   builtIn: false,
+                  managed: true,
+                  forceEnabled: st.forceEnabled,
                 };
 
                 await pluginStorage.saveThemeCSS(st.id, sanitized.css);
@@ -293,18 +340,17 @@ export const useThemeStore = create<ThemeState>()(
                   };
                 });
 
-                // If this is force-enabled and no theme is active, activate it
-                if (st.forceEnabled && !get().activeThemeId) {
-                  applyCustomThemeCSS(theme, get().resolvedTheme);
-                  set({ activeThemeId: st.id });
-                }
-              } else if (!local.builtIn && local.version !== st.version) {
-                // Version changed — re-download CSS
-                const css = await downloadThemeCSS(st.id);
-                if (!css) continue;
+              } else if (!local.builtIn) {
+                let css = local.css;
 
-                const sanitized = sanitizeThemeCSS(css);
-                await pluginStorage.saveThemeCSS(st.id, sanitized.css);
+                if (local.version !== st.version || !css) {
+                  const downloadedCss = await downloadThemeCSS(st.id);
+                  if (!downloadedCss) continue;
+
+                  const sanitized = sanitizeThemeCSS(downloadedCss);
+                  css = sanitized.css;
+                  await pluginStorage.saveThemeCSS(st.id, sanitized.css);
+                }
 
                 const updatedTheme = {
                   ...local,
@@ -312,8 +358,10 @@ export const useThemeStore = create<ThemeState>()(
                   version: st.version,
                   author: st.author,
                   description: st.description || '',
-                  css: sanitized.css,
+                  css,
                   variants: st.variants as ThemeVariant[],
+                  managed: true,
+                  forceEnabled: st.forceEnabled,
                 };
 
                 set(state => ({
@@ -332,6 +380,15 @@ export const useThemeStore = create<ThemeState>()(
             set(state => ({
               installedThemes: dedupeInstalledThemes(state.installedThemes),
             }));
+
+            const forcedThemeId = getForcedThemeId(get().installedThemes);
+            if (forcedThemeId && get().activeThemeId !== forcedThemeId) {
+              const forcedTheme = get().installedThemes.find((theme) => theme.id === forcedThemeId);
+              if (forcedTheme) {
+                applyCustomThemeCSS(forcedTheme, get().resolvedTheme);
+                set({ activeThemeId: forcedThemeId });
+              }
+            }
           } catch {
             console.warn('[theme-store] Server theme sync failed');
           }
@@ -413,6 +470,8 @@ function dedupeInstalledThemes(themes: InstalledTheme[]): InstalledTheme[] {
       ...theme,
       builtIn: existing.builtIn || theme.builtIn,
       enabled: existing.enabled || theme.enabled,
+      managed: existing.managed || theme.managed,
+      forceEnabled: theme.forceEnabled ?? existing.forceEnabled,
     });
   }