diff --git a/AGENTS.md b/AGENTS.md
index 0c9571c..c7bdce8 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -10,7 +10,7 @@ Repo-specific only. Global rules live in `~/.config/opencode/AGENTS.md`.
 pnpm dev              # dev server (port 3000)
 pnpm build            # production build → .output/
 pnpm generate         # static generation
-pnpm preview          # preview .output/
+pnpm preview          # preview .output/ on port 3001 (separate origin from dev — prevents SW from leaking into dev mode)
 
 pnpm lint             # eslint (exit 0 on warnings-only)
 pnpm lint:fix         # eslint --fix
@@ -92,13 +92,12 @@ app/
     tanstack-table.ts # valueUpdater helper for @tanstack/vue-table
     tw-helper.ts      # tw() tagged template for Tailwind autocomplete
   plugins/
-    nurekit.ts        # provides $nurekit (dev: /api proxy; prod: sh.mindenit.org/api)
+    nurekit.ts        # provides $nurekit — SDK default baseUrl: https://sh.mindenit.org/api
     vue-query.ts      # TanStack Query client + IndexedDB persistence
   assets/css/
     tailwind.css      # single canonical CSS — Tailwind v4 + UI Thing base + full token/palette set
 server/
-  api/[...any].ts     # dev-only reverse proxy → https://sh.mindenit.org/api (404 in prod)
-  routes/             # server routes (currently empty)
+  routes/             # server routes (health, ready)
 ```
 
 ---
@@ -117,7 +116,7 @@ Beyond Nuxt's defaults, `nuxt.config` adds:
 ```
 @nuxt/scripts             # third-party script loading (includes useScriptGoogleAnalytics)
 @nuxt/eslint              # ESLint with generated .nuxt/eslint.config.mjs
-@nuxt/icon                # icon component, iconify provider, lucide bundled
+@nuxt/icon                # icon component; client bundle (18 KB) holds all 59 used icons inline
 @nuxtjs/color-mode        # dark/light/system mode via .dark class
 @vueuse/nuxt              # VueUse composables auto-imported
 @pinia/nuxt               # Pinia state management
@@ -133,6 +132,14 @@ vue-sonner/nuxt           # toast notifications
 
 `@nuxtjs/seo` bundles: sitemap (`/sitemap.xml`), robots, nuxt-schema-org, og-image (1200×630, 7-day cache). All configured in `nuxt.config`.
 
+### Icon strategy
+
+All 59 used icons are inlined in the client JS bundle (18 KB, scan-generated at build time). Rendering order: **client bundle → same-origin `/_icons` server route (SW SWR-cached) → api.iconify.design CDN (online fallback only)**.
+
+`serverBundle: false` — no full collection JSONs in the Nitro server bundle (logos + ph alone would add 12 MB). Icons render client-side after hydration; no SSR flash for these small icons.
+
+**Adding an icon from a new collection:** install its `@iconify-json/<name>` package as a devDep (`pnpm add -D @iconify-json/<name>`) and add the collection name to `icon.serverBundle.collections` in `nuxt.config.ts` only if you want SSR rendering for that collection.
+
 ---
 
 ## Component system — UI Thing (migrated from shadcn-nuxt)
@@ -163,7 +170,7 @@ vue-sonner/nuxt           # toast notifications
 
 ### API client — `$nurekit`
 
-Injected by `app/plugins/nurekit.ts`. In dev it points at `window.location.origin/api` (proxied by `server/api/[...any].ts` to `https://sh.mindenit.org/api`); in prod it uses the SDK's default. Always access via `useNuxtApp().$nurekit` inside query factories.
+Injected by `app/plugins/nurekit.ts`. Uses the SDK default baseUrl (`https://sh.mindenit.org/api`) in both dev and prod — no server-side proxy. Always access via `useNuxtApp().$nurekit` inside query factories.
 
 ### Server state — TanStack Vue Query
 
diff --git a/app/app.vue b/app/app.vue
index 6b0eca7..c9a351a 100644
--- a/app/app.vue
+++ b/app/app.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 import { defineAsyncComponent } from "vue"
 
 /**
@@ -7,7 +7,7 @@ import { defineAsyncComponent } from "vue"
  * toggle the setting pay nothing for it. Wrapped in <ClientOnly> already, so
  * SSR doesn't try to resolve the dynamic import.
  */
-const SnowEffect = defineAsyncComponent(() => import("~/components/SnowEffect.vue"))
+const SnowEffect = defineAsyncComponent(() => import("~/components/backgrounds/SnowEffect.vue"))
 
 const { isSnowEnabled, isShortcutsOpen } = useAppShell()
 </script>
diff --git a/app/components/AppShortcutsDialog.vue b/app/components/AppShortcutsDialog.vue
index 4c1ead9..8740c08 100644
--- a/app/components/AppShortcutsDialog.vue
+++ b/app/components/AppShortcutsDialog.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 const open = defineModel<boolean>("open", { required: true })
 </script>
 
diff --git a/app/components/DialogManager.vue b/app/components/DialogManager.vue
index e6ea1c0..4e8ab62 100644
--- a/app/components/DialogManager.vue
+++ b/app/components/DialogManager.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 const { currentDialog, isDialogOpen, closeDialog, initializeDialogs } = useDialogManager()
 
 onMounted(() => {
diff --git a/app/components/OgImage/Mindenit.satori.vue b/app/components/OgImage/Mindenit.satori.vue
index cdbd5cd..4856220 100644
--- a/app/components/OgImage/Mindenit.satori.vue
+++ b/app/components/OgImage/Mindenit.satori.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 interface Props {
 	title?: string
 	description?: string
diff --git a/app/components/SidebarTodayEvents.vue b/app/components/SidebarTodayEvents.vue
index 45ac38b..5afdd17 100644
--- a/app/components/SidebarTodayEvents.vue
+++ b/app/components/SidebarTodayEvents.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 import { addDays, subDays, isToday } from "date-fns"
 import { formatInTimeZone } from "date-fns-tz"
 import { storeToRefs } from "pinia"
diff --git a/app/components/TheLoader.vue b/app/components/TheLoader.vue
index cd30ce1..0f93d38 100644
--- a/app/components/TheLoader.vue
+++ b/app/components/TheLoader.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 interface Props {
 	size?: "lg" | "md" | "sm"
 }
diff --git a/app/components/ThemeSwitcher.vue b/app/components/ThemeSwitcher.vue
index 89e2939..48bfe06 100644
--- a/app/components/ThemeSwitcher.vue
+++ b/app/components/ThemeSwitcher.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 const colorMode = useColorMode()
 const { trackEvent } = useAnalytics()
 
diff --git a/app/components/SnowEffect.vue b/app/components/backgrounds/SnowEffect.vue
similarity index 100%
rename from app/components/SnowEffect.vue
rename to app/components/backgrounds/SnowEffect.vue
diff --git a/app/components/WaitHand.vue b/app/components/backgrounds/WaitHand.vue
similarity index 98%
rename from app/components/WaitHand.vue
rename to app/components/backgrounds/WaitHand.vue
index a882fc7..a95b5e9 100644
--- a/app/components/WaitHand.vue
+++ b/app/components/backgrounds/WaitHand.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup></script>
+<script setup lang="ts"></script>
 <template>
 	<div
 		class="relative mt-24 ml-20 h-15 w-20"
diff --git a/app/components/AppOfflineBanner.vue b/app/components/banners/AppOfflineBanner.vue
similarity index 68%
rename from app/components/AppOfflineBanner.vue
rename to app/components/banners/AppOfflineBanner.vue
index de494c7..96bf96e 100644
--- a/app/components/AppOfflineBanner.vue
+++ b/app/components/banners/AppOfflineBanner.vue
@@ -1,8 +1,16 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 const isOnline = useOnline()
 const wasOffline = ref(false)
 const showReconnected = ref(false)
 
+const calendarStore = useCalendarStore()
+const { lastUpdatedAt } = storeToRefs(calendarStore)
+const { tzFormat } = useTimezone()
+
+const lastFetchTime = computed(() =>
+	lastUpdatedAt.value > 0 ? tzFormat(new Date(lastUpdatedAt.value), "HH:mm") : null
+)
+
 watch(isOnline, (online) => {
 	if (!online) {
 		wasOffline.value = true
@@ -34,7 +42,11 @@ watch(isOnline, (online) => {
 			aria-live="assertive"
 		>
 			<AppIcon name="lucide:wifi-off" class="shrink-0" aria-hidden="true" />
-			<span>Без з'єднання — показано збережені дані</span>
+			<span>
+				Без з'єднання —
+				<template v-if="lastFetchTime">дані від {{ lastFetchTime }}</template>
+				<template v-else>показано збережені дані</template>
+			</span>
 		</div>
 	</Transition>
 </template>
diff --git a/app/components/ConsentBanner.vue b/app/components/banners/ConsentBanner.vue
similarity index 100%
rename from app/components/ConsentBanner.vue
rename to app/components/banners/ConsentBanner.vue
diff --git a/app/components/HiringInfo.vue b/app/components/banners/HiringInfo.vue
similarity index 100%
rename from app/components/HiringInfo.vue
rename to app/components/banners/HiringInfo.vue
diff --git a/app/components/ScheduleEphemeralBanner.vue b/app/components/banners/ScheduleEphemeralBanner.vue
similarity index 99%
rename from app/components/ScheduleEphemeralBanner.vue
rename to app/components/banners/ScheduleEphemeralBanner.vue
index 0eb5479..e5d9a5e 100644
--- a/app/components/ScheduleEphemeralBanner.vue
+++ b/app/components/banners/ScheduleEphemeralBanner.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 interface Props {
 	variant?: "banner" | "card"
 }
diff --git a/app/components/calendar/Root.vue b/app/components/calendar/Root.vue
index eb2574c..bbd8aa0 100644
--- a/app/components/calendar/Root.vue
+++ b/app/components/calendar/Root.vue
@@ -6,6 +6,7 @@ interface Props {
 	events: Schedule[]
 	hasActiveSchedule: boolean
 	isLoading: boolean
+	isOfflineNoData: boolean
 	error: Error | null
 	scheduleName?: string
 }
@@ -14,7 +15,7 @@ const props = defineProps<Props>()
 const calendarStore = useCalendarStore()
 const { view } = storeToRefs(calendarStore)
 const { trackEvent } = useAnalytics()
-const isAddDialogOpen = useState("schedule:add-dialog:open", () => false)
+const isAddDialogOpen = useState(DIALOG_KEYS.scheduleAdd, () => false)
 
 // SSR renders the calendar with no localStorage access, so hasActiveSchedule is
 // always false on the server. This causes a hydration mismatch on blur-sm and the
@@ -52,13 +53,15 @@ watch(
 
 const showOverlay = computed(() => {
 	if (isHydrating.value) return true
-	return !props.hasActiveSchedule || props.isLoading || !!props.error
+	return !props.hasActiveSchedule || props.isLoading || props.isOfflineNoData || !!props.error
 })
 
 const overlayContent = computed(() => {
 	if (isHydrating.value) return "loading"
 	if (!props.hasActiveSchedule) return "no-schedule"
 	if (props.isLoading) return "loading"
+	// Offline and TanStack query never resolved (no cached data in IDB).
+	if (props.isOfflineNoData) return "offline-no-data"
 	if (props.error) return "error"
 	return null
 })
@@ -163,6 +166,15 @@ const overlayContent = computed(() => {
 					class="pointer-events-auto"
 				/>
 
+				<AppEmptyState
+					v-else-if="overlayContent === 'offline-no-data'"
+					variant="card"
+					icon="lucide:wifi-off"
+					title="Немає з'єднання"
+					description="Збережених даних для цього розкладу немає"
+					class="pointer-events-auto"
+				/>
+
 				<UiAlert
 					v-else-if="overlayContent === 'error'"
 					variant="destructive"
diff --git a/app/components/schedule/AddDialog.vue b/app/components/schedule/AddDialog.vue
index 5e6bd08..4ecddec 100644
--- a/app/components/schedule/AddDialog.vue
+++ b/app/components/schedule/AddDialog.vue
@@ -16,7 +16,7 @@ const activeTab = ref<ScheduleTabType>("group")
 
 // useState makes the open state globally accessible — e.g. Root.vue's
 // "no schedule" CTA can open this dialog without prop drilling.
-const isDialogOpen = useState("schedule:add-dialog:open", () => false)
+const isDialogOpen = useState(DIALOG_KEYS.scheduleAdd, () => false)
 
 const {
 	data: groups,
diff --git a/app/components/schedule/AddDialogTrigger.vue b/app/components/schedule/AddDialogTrigger.vue
index 050580a..deddedc 100644
--- a/app/components/schedule/AddDialogTrigger.vue
+++ b/app/components/schedule/AddDialogTrigger.vue
@@ -5,7 +5,7 @@ interface Props {
 
 defineProps<Props>()
 
-const isDialogOpen = useState("schedule:add-dialog:open", () => false)
+const isDialogOpen = useState(DIALOG_KEYS.scheduleAdd, () => false)
 </script>
 
 <template>
diff --git a/app/components/schedule/DialogCard.vue b/app/components/schedule/DialogCard.vue
index d2a6f78..7516cf0 100644
--- a/app/components/schedule/DialogCard.vue
+++ b/app/components/schedule/DialogCard.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 import { SCHEDULE_ICONS } from "~/constants/schedule"
 import type { ScheduleTabType } from "~/types/schedule"
 
diff --git a/app/components/settings/ScheduleTab.vue b/app/components/settings/ScheduleTab.vue
index f6b11ae..c8c289b 100644
--- a/app/components/settings/ScheduleTab.vue
+++ b/app/components/settings/ScheduleTab.vue
@@ -21,8 +21,8 @@ const { selectedSchedule } = storeToRefs(scheduleStore)
 const { exportAcademicYearSchedule, isLoading } = useScheduleIcsExport()
 
 // Shared state — useState keys keep one ref across all call-sites.
-const isShortcutsOpen = useState("shortcuts:open", () => false)
-const isSettingsOpen = useState("settings:open", () => false)
+const isShortcutsOpen = useState(DIALOG_KEYS.shortcuts, () => false)
+const isSettingsOpen = useState(DIALOG_KEYS.settings, () => false)
 
 async function openShortcuts() {
 	// Close settings first; wait a tick so Reka tears down its overlay before
diff --git a/app/components/SettingsDialog.vue b/app/components/settings/SettingsDialog.vue
similarity index 94%
rename from app/components/SettingsDialog.vue
rename to app/components/settings/SettingsDialog.vue
index 34b6204..959f891 100644
--- a/app/components/SettingsDialog.vue
+++ b/app/components/settings/SettingsDialog.vue
@@ -1,7 +1,7 @@
 <script setup lang="ts">
 const { trackEvent } = useAnalytics()
 
-const isOpen = useState("settings:open", () => false)
+const isOpen = useState(DIALOG_KEYS.settings, () => false)
 
 function onOpenChange(open: boolean) {
 	isOpen.value = open
diff --git a/app/components/SettingsLinksManagement.vue b/app/components/settings/SettingsLinksManagement.vue
similarity index 100%
rename from app/components/SettingsLinksManagement.vue
rename to app/components/settings/SettingsLinksManagement.vue
diff --git a/app/components/SettingsMainView.vue b/app/components/settings/SettingsMainView.vue
similarity index 100%
rename from app/components/SettingsMainView.vue
rename to app/components/settings/SettingsMainView.vue
diff --git a/app/composables/useDialogManager.ts b/app/composables/useDialogManager.ts
index 5495800..cb75aaf 100644
--- a/app/composables/useDialogManager.ts
+++ b/app/composables/useDialogManager.ts
@@ -1,10 +1,10 @@
-import { useLocalStorage } from "@vueuse/core"
+import { useStorage } from "@vueuse/core"
 import type { DialogConfig } from "~/constants/dialogs"
 import { DIALOGS_CONFIG } from "~/constants/dialogs"
 import { STORAGE_KEYS } from "~/constants/storage"
 
 export const useDialogManager = () => {
-	const shownDialogs = useLocalStorage<Record<string, { version: number; lastShown: string }>>(
+	const shownDialogs = useStorage<Record<string, { version: number; lastShown: string }>>(
 		STORAGE_KEYS.dialogsShown,
 		{}
 	)
diff --git a/app/composables/useIcsExport.ts b/app/composables/useIcsExport.ts
index 27b23be..ee17838 100644
--- a/app/composables/useIcsExport.ts
+++ b/app/composables/useIcsExport.ts
@@ -1,10 +1,7 @@
 import type { Schedule } from "@mindenit/nurekit"
 import { formatInTimeZone } from "date-fns-tz"
-import { storeToRefs } from "pinia"
 import { downloadFile } from "~/utils/download"
 import { EVENT_TYPE_LABELS } from "~/constants/calendar"
-import { resolveTimezone } from "~/constants/timezones"
-import { useSettingsStore } from "~/stores/settings"
 
 export interface IcsExportOptions {
 	academicYearStart?: Date
@@ -13,8 +10,7 @@ export interface IcsExportOptions {
 }
 
 export const useIcsExport = () => {
-	const { timezone } = storeToRefs(useSettingsStore())
-	const effectiveTimezone = computed(() => resolveTimezone(timezone.value))
+	const { effectiveTimezone } = useTimezone()
 
 	/**
 	 * Format a Unix seconds timestamp as an ICS datetime string.
diff --git a/app/composables/useKeyboardShortcuts.ts b/app/composables/useKeyboardShortcuts.ts
index 528b317..6eeaa35 100644
--- a/app/composables/useKeyboardShortcuts.ts
+++ b/app/composables/useKeyboardShortcuts.ts
@@ -1,3 +1,5 @@
+import { DIALOG_KEYS } from "~/constants/dialogs"
+
 /**
  * Registers global keyboard shortcuts for calendar navigation.
  *
@@ -13,7 +15,7 @@ export function useKeyboardShortcuts() {
 	const { trackEvent } = useAnalytics()
 
 	// useState keeps one shared ref across all composable call-sites (app.vue + settings).
-	const isShortcutsOpen = useState("shortcuts:open", () => false)
+	const isShortcutsOpen = useState(DIALOG_KEYS.shortcuts, () => false)
 
 	function isInInteractiveContext(e: KeyboardEvent): boolean {
 		const target = e.target as HTMLElement
diff --git a/app/constants/dialogs.ts b/app/constants/dialogs.ts
index c6bbae6..5b0db21 100644
--- a/app/constants/dialogs.ts
+++ b/app/constants/dialogs.ts
@@ -1,11 +1,6 @@
-export interface DialogConfig {
-	id: string
-	version: number
-	priority: number // Lower number means higher priority
-	enabled: boolean
-	component: string
-	minShowInterval?: number
-}
+import type { DialogConfig } from "~/types/dialogs"
+
+export type { DialogConfig }
 
 export const DIALOGS_CONFIG: DialogConfig[] = [
 	{
@@ -16,3 +11,10 @@ export const DIALOGS_CONFIG: DialogConfig[] = [
 		component: "AppDialog",
 	},
 ]
+
+/** useState keys for cross-component dialog open state. */
+export const DIALOG_KEYS = {
+	settings: "settings:open",
+	shortcuts: "shortcuts:open",
+	scheduleAdd: "schedule:add-dialog:open",
+} as const
diff --git a/app/constants/storage.ts b/app/constants/storage.ts
index 8053847..c5525ab 100644
--- a/app/constants/storage.ts
+++ b/app/constants/storage.ts
@@ -35,6 +35,9 @@ export const STORAGE_KEYS = {
 	// Maintenance bypass cookie (set via /maintenance dev access flow)
 	devAccess: "mindenit:dev-access",
 
+	// One-time first-visit tracking (set true after first-ever page load)
+	firstVisitSeen: "mindenit:first-visit-seen",
+
 	// Analytics consent ("accepted" | "declined" | null means not yet decided)
 	analyticsConsent: "mindenit:analytics-consent",
 
diff --git a/app/pages/blocked.vue b/app/pages/blocked.vue
index 42896f9..eb0f1bd 100644
--- a/app/pages/blocked.vue
+++ b/app/pages/blocked.vue
@@ -1,4 +1,4 @@
-<script lang="ts" setup>
+<script setup lang="ts">
 useSeo({
 	title: "Виявлено шкідливий браузер",
 	noindex: true,
diff --git a/app/pages/index.vue b/app/pages/index.vue
index 0da7af2..8f028b3 100644
--- a/app/pages/index.vue
+++ b/app/pages/index.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { storeToRefs } from "pinia"
+import { skipHydrate, storeToRefs } from "pinia"
 import { useScheduleQuery } from "~/composables/useScheduleQuery"
 
 const calendarStore = useCalendarStore()
@@ -9,7 +9,8 @@ const { trackEvent } = useAnalytics()
 useUrlState()
 
 // Fire once on the very first visit when no schedules are configured.
-const hasSeenFirstVisit = useLocalStorage("op-first-visit-seen", false)
+// skipHydrate prevents SSR/client mismatch (matches pattern in other stores/pages).
+const hasSeenFirstVisit = skipHydrate(useLocalStorage(STORAGE_KEYS.firstVisitSeen, false))
 onMounted(() => {
 	if (!hasSeenFirstVisit.value && scheduleStore.allSchedules.length === 0) {
 		hasSeenFirstVisit.value = true
@@ -38,19 +39,14 @@ const hasActiveSchedule = computed(() => !!selectedSchedule.value)
 const scheduleId = computed(() => selectedSchedule.value?.id)
 
 const getAcademicYearRange = (date: Date) => {
-	const year = date.getFullYear()
-	const currentDate = new Date(date)
-
-	if (currentDate.getMonth() < 8) {
-		return {
-			start: new Date(year - 1, 8, 1, 0, 0, 0, 0),
-			end: new Date(year, 8, 1, 23, 59, 59, 999),
-		}
-	}
-
+	// Academic year: Sept 1 → Sept 1. Pad ±7 days so month/week grid cells
+	// that overhang the boundary (up to 6 days in either direction) still have
+	// events fetched. Without the pad, September cells in August's grid and
+	// August cells in September's grid render empty.
+	const startYear = date.getMonth() < 8 ? date.getFullYear() - 1 : date.getFullYear()
 	return {
-		start: new Date(year, 8, 1, 0, 0, 0, 0),
-		end: new Date(year + 1, 8, 1, 23, 59, 59, 999),
+		start: new Date(startYear, 8, 1 - 7, 0, 0, 0, 0),
+		end: new Date(startYear + 1, 8, 1 + 7, 23, 59, 59, 999),
 	}
 }
 
@@ -70,8 +66,21 @@ const {
 	data: scheduleData,
 	error,
 	isLoading,
+	// dataUpdatedAt — Unix ms of the last successful fetch; 0 when never fetched.
+	// Comes from TanStack Query directly; no extra work needed.
+	dataUpdatedAt,
+	// fetchStatus: "fetching" | "paused" | "idle"
+	// status: "pending" | "error" | "success"
+	// "paused" + "pending" = network offline, query never resolved yet.
+	fetchStatus,
+	status,
 } = useScheduleQuery(scheduleId, startTimestamp, endTimestamp)
 
+// Offline AND no cached data yet (TanStack v5 networkMode: "online" default:
+// the query pauses instead of erroring when connectivity is absent).
+// Must be a separate computed so Root.vue can pick the right overlay branch.
+const isOfflineNoData = computed(() => fetchStatus.value === "paused" && status.value === "pending")
+
 // Identify the active schedule by a stable string key — avoids a deep object watch.
 const scheduleKey = computed(() =>
 	selectedSchedule.value ? `${selectedSchedule.value.type}-${selectedSchedule.value.id}` : null
@@ -92,9 +101,9 @@ watch(scheduleKey, (newKey, oldKey) => {
 // is already populated but the watcher never fires — allEvents stays [] and
 // no events render until the next query refetch or server restart.
 watch(
-	scheduleData,
-	(data) => {
-		if (data) calendarStore.setEvents(data)
+	[scheduleData, dataUpdatedAt],
+	([data, updatedAt]) => {
+		if (data) calendarStore.setEvents(data, updatedAt)
 	},
 	{ immediate: true }
 )
@@ -105,6 +114,7 @@ watch(
 		:events="filteredEvents"
 		:has-active-schedule="!!hasActiveSchedule"
 		:is-loading="isLoading"
+		:is-offline-no-data="isOfflineNoData"
 		:error="error"
 		:schedule-name="selectedSchedule?.name"
 	/>
diff --git a/app/plugins/sw.client.ts b/app/plugins/sw.client.ts
new file mode 100644
index 0000000..f81e414
--- /dev/null
+++ b/app/plugins/sw.client.ts
@@ -0,0 +1,27 @@
+/**
+ * Service worker registration — client-side only.
+ * In dev: actively unregister any existing SW and clear mindenit-* caches so
+ * a previously-installed prod/preview SW cannot intercept Vite's dev URLs.
+ */
+export default defineNuxtPlugin(() => {
+	if (!("serviceWorker" in navigator)) return
+
+	if (import.meta.dev) {
+		// Tear down any leftover SW from a previous preview/prod run.
+		navigator.serviceWorker
+			.getRegistrations()
+			.then((regs) => regs.forEach((r) => r.unregister()))
+		caches
+			.keys()
+			.then((keys) =>
+				keys.filter((k) => k.startsWith("mindenit-")).forEach((k) => caches.delete(k))
+			)
+		return
+	}
+
+	window.addEventListener("load", () => {
+		navigator.serviceWorker.register("/sw.js").catch((err) => {
+			console.error("[SW] registration failed:", err)
+		})
+	})
+})
diff --git a/app/queries/auditoriums.ts b/app/queries/auditoriums.ts
index 1265e5f..b7c9e4a 100644
--- a/app/queries/auditoriums.ts
+++ b/app/queries/auditoriums.ts
@@ -1,13 +1,7 @@
 import type { MaybeRefOrGetter } from "vue"
+import type { ScheduleFilters } from "~/types/schedule"
 import { listOptions, metadataOptions, scheduleOptions } from "./_factories"
 
-type AuditoriumScheduleFilters = {
-	lessonTypes?: MaybeRefOrGetter<string[]>
-	teachers?: MaybeRefOrGetter<number[]>
-	groups?: MaybeRefOrGetter<number[]>
-	subjects?: MaybeRefOrGetter<number[]>
-}
-
 const auditoriumsOptions = () => {
 	const { $nurekit } = useNuxtApp()
 	return listOptions("auditoriums", () => $nurekit.auditoriums.getAll())
@@ -17,7 +11,7 @@ const auditoriumScheduleOptions = (
 	auditoriumId: MaybeRefOrGetter<number | string>,
 	startedAt: MaybeRefOrGetter<number | string>,
 	endedAt: MaybeRefOrGetter<number | string>,
-	filters: AuditoriumScheduleFilters = {}
+	filters: ScheduleFilters = {}
 ) => {
 	const { $nurekit } = useNuxtApp()
 	return scheduleOptions(
diff --git a/app/queries/groups.ts b/app/queries/groups.ts
index 79f11cc..25f5959 100644
--- a/app/queries/groups.ts
+++ b/app/queries/groups.ts
@@ -1,13 +1,7 @@
 import type { MaybeRefOrGetter } from "vue"
+import type { ScheduleFilters } from "~/types/schedule"
 import { listOptions, metadataOptions, scheduleOptions } from "./_factories"
 
-type GroupScheduleFilters = {
-	auditoriums?: MaybeRefOrGetter<number[]>
-	lessonTypes?: MaybeRefOrGetter<string[]>
-	teachers?: MaybeRefOrGetter<number[]>
-	subjects?: MaybeRefOrGetter<number[]>
-}
-
 const groupsOptions = () => {
 	const { $nurekit } = useNuxtApp()
 	return listOptions("groups", () => $nurekit.groups.getAll())
@@ -17,7 +11,7 @@ const groupScheduleOptions = (
 	groupId: MaybeRefOrGetter<number | string>,
 	startedAt: MaybeRefOrGetter<number | string>,
 	endedAt: MaybeRefOrGetter<number | string>,
-	filters: GroupScheduleFilters = {}
+	filters: ScheduleFilters = {}
 ) => {
 	const { $nurekit } = useNuxtApp()
 	return scheduleOptions("groupSchedule", groupId, startedAt, endedAt, filters, (args) =>
diff --git a/app/queries/teachers.ts b/app/queries/teachers.ts
index d80ec13..fde9a38 100644
--- a/app/queries/teachers.ts
+++ b/app/queries/teachers.ts
@@ -1,13 +1,7 @@
 import type { MaybeRefOrGetter } from "vue"
+import type { ScheduleFilters } from "~/types/schedule"
 import { listOptions, metadataOptions, scheduleOptions } from "./_factories"
 
-type TeacherScheduleFilters = {
-	lessonTypes?: MaybeRefOrGetter<string[]>
-	groups?: MaybeRefOrGetter<number[]>
-	auditoriums?: MaybeRefOrGetter<number[]>
-	subjects?: MaybeRefOrGetter<number[]>
-}
-
 const teachersOptions = () => {
 	const { $nurekit } = useNuxtApp()
 	return listOptions("teachers", () => $nurekit.teachers.getAll())
@@ -17,7 +11,7 @@ const teacherScheduleOptions = (
 	teacherId: MaybeRefOrGetter<number | string>,
 	startedAt: MaybeRefOrGetter<number | string>,
 	endedAt: MaybeRefOrGetter<number | string>,
-	filters: TeacherScheduleFilters = {}
+	filters: ScheduleFilters = {}
 ) => {
 	const { $nurekit } = useNuxtApp()
 	return scheduleOptions("teacherSchedule", teacherId, startedAt, endedAt, filters, (args) =>
diff --git a/app/stores/calendar.ts b/app/stores/calendar.ts
index bff87d8..7907d9d 100644
--- a/app/stores/calendar.ts
+++ b/app/stores/calendar.ts
@@ -1,20 +1,23 @@
-import { defineStore, storeToRefs } from "pinia"
+import { defineStore } from "pinia"
 import { startOfMonth, endOfMonth, startOfWeek, endOfWeek, startOfYear, endOfYear } from "date-fns"
 import type { Schedule } from "@mindenit/nurekit"
 import type { TCalendarView } from "~/types/calendar"
 import { WEEK_OPTIONS } from "~/constants/calendar"
 import { STORAGE_KEYS } from "~/constants/storage"
-import { resolveTimezone } from "~/constants/timezones"
 import { getEventDayKey } from "~/utils/event-cache"
 
 const VALID_VIEWS: TCalendarView[] = ["month", "week", "day", "year"]
 
 export const useCalendarStore = defineStore("calendar", () => {
-	const settingsStore = useSettingsStore()
-	const { timezone } = storeToRefs(settingsStore)
-	const effectiveTimezone = computed(() => resolveTimezone(timezone.value))
+	const { effectiveTimezone } = useTimezone()
 
 	const allEvents = ref<Schedule[]>([])
+	// Unix ms timestamp of the last successful schedule fetch.
+	// 0 = never fetched (or cache not yet restored from IDB).
+	// Fed from TanStack Query's dataUpdatedAt in pages/index.vue.
+	// Not persisted — IDB cache restoration restores the real dataUpdatedAt
+	// on every page load, so index.vue sets this immediately after hydration.
+	const lastUpdatedAt = ref(0)
 	// useState keeps the value stable across SSR → client hydration.
 	// ref(new Date()) would differ between server render time and client
 	// hydration time, causing a hydration mismatch on every page load.
@@ -143,8 +146,9 @@ export const useCalendarStore = defineStore("calendar", () => {
 		})
 	}
 
-	function setEvents(initialEvents: Schedule[]) {
+	function setEvents(initialEvents: Schedule[], updatedAt?: number) {
 		allEvents.value = initialEvents
+		if (updatedAt) lastUpdatedAt.value = updatedAt
 	}
 
 	function setView(newView: TCalendarView) {
@@ -163,6 +167,7 @@ export const useCalendarStore = defineStore("calendar", () => {
 
 	return {
 		allEvents,
+		lastUpdatedAt,
 		selectedDate,
 		view,
 		filteredEvents,
diff --git a/app/stores/filters.ts b/app/stores/filters.ts
index 50c97ef..3e390ed 100644
--- a/app/stores/filters.ts
+++ b/app/stores/filters.ts
@@ -1,3 +1,5 @@
+import { useStorage } from "@vueuse/core"
+import { skipHydrate } from "pinia"
 import { STORAGE_KEYS } from "~/constants/storage"
 
 type FilterKey = "lessonTypes" | "teachers" | "auditoriums" | "subjects" | "groups"
@@ -20,29 +22,13 @@ const emptyState = (): FilterState => ({
 	groups: [],
 })
 
-export const useFiltersStore = defineStore("filters", () => {
-	const state = ref<FilterState>(emptyState())
-
-	let currentStorageKey = ""
-
-	const ensureArray = <T>(v: unknown): T[] => (Array.isArray(v) ? (v as T[]) : [])
-
-	const loadFilters = (scheduleId: string | number, scheduleType: string) => {
-		const key = STORAGE_KEYS.filters(scheduleType, scheduleId)
-		if (key === currentStorageKey) return
-		currentStorageKey = key
-
-		if (!import.meta.client) return
-
-		const saved = localStorage.getItem(key)
-		if (!saved) {
-			state.value = emptyState()
-			return
-		}
+const ensureArray = <T>(v: unknown): T[] => (Array.isArray(v) ? (v as T[]) : [])
 
+const filterSerializer = {
+	read: (raw: string): FilterState => {
 		try {
-			const parsed = JSON.parse(saved) as Partial<FilterState>
-			state.value = {
+			const parsed = JSON.parse(raw) as Partial<FilterState>
+			return {
 				lessonTypes: ensureArray<string>(parsed.lessonTypes),
 				teachers: ensureArray<number>(parsed.teachers),
 				auditoriums: ensureArray<number>(parsed.auditoriums),
@@ -50,13 +36,28 @@ export const useFiltersStore = defineStore("filters", () => {
 				groups: ensureArray<number>(parsed.groups),
 			}
 		} catch {
-			state.value = emptyState()
+			return emptyState()
 		}
-	}
+	},
+	write: (val: FilterState): string => JSON.stringify(val),
+}
+
+export const useFiltersStore = defineStore("filters", () => {
+	// Reactive storage key — swapped by loadFilters() when the user changes schedule.
+	const storageKey = ref("")
+
+	// useStorage is re-evaluated reactively when storageKey changes.
+	// skipHydrate prevents SSR/client mismatch (same pattern as other stores).
+	const state = skipHydrate(
+		useStorage<FilterState>(storageKey, emptyState, undefined, {
+			serializer: filterSerializer,
+		})
+	)
 
-	const saveFilters = () => {
-		if (!import.meta.client || !currentStorageKey) return
-		localStorage.setItem(currentStorageKey, JSON.stringify(state.value))
+	const loadFilters = (scheduleId: string | number, scheduleType: string) => {
+		const key = STORAGE_KEYS.filters(scheduleType, scheduleId)
+		if (key === storageKey.value) return
+		storageKey.value = key
 	}
 
 	const toggle = <K extends FilterKey>(key: K, value: FilterValue<K>) => {
@@ -64,7 +65,6 @@ export const useFiltersStore = defineStore("filters", () => {
 		const index = arr.indexOf(value)
 		if (index > -1) arr.splice(index, 1)
 		else arr.push(value)
-		saveFilters()
 	}
 
 	const isActive = <K extends FilterKey>(key: K, value: FilterValue<K>) => {
@@ -73,7 +73,6 @@ export const useFiltersStore = defineStore("filters", () => {
 
 	const clearAll = () => {
 		state.value = emptyState()
-		saveFilters()
 	}
 
 	// Per-type computed refs for reactive reads in templates and queries.
@@ -169,7 +168,6 @@ export const useFiltersStore = defineStore("filters", () => {
 		hasActive,
 		activeCount,
 		loadFilters,
-		saveFilters,
 		toggle,
 		isActive,
 		filtersForType,
diff --git a/app/types/dialogs.ts b/app/types/dialogs.ts
new file mode 100644
index 0000000..f147a47
--- /dev/null
+++ b/app/types/dialogs.ts
@@ -0,0 +1,8 @@
+export interface DialogConfig {
+	id: string
+	version: number
+	priority: number // Lower number means higher priority
+	enabled: boolean
+	component: string
+	minShowInterval?: number
+}
diff --git a/app/types/schedule.ts b/app/types/schedule.ts
index de0c1dd..9210e8e 100644
--- a/app/types/schedule.ts
+++ b/app/types/schedule.ts
@@ -1,3 +1,5 @@
+import type { MaybeRefOrGetter } from "vue"
+
 export interface GenericScheduleItem {
 	id: number
 	name: string
@@ -5,3 +7,12 @@ export interface GenericScheduleItem {
 }
 
 export type ScheduleTabType = "group" | "teacher" | "auditorium"
+
+/** Shared filter shape for all entity schedule queries (groups, teachers, auditoriums). */
+export type ScheduleFilters = {
+	auditoriums?: MaybeRefOrGetter<number[]>
+	lessonTypes?: MaybeRefOrGetter<string[]>
+	teachers?: MaybeRefOrGetter<number[]>
+	subjects?: MaybeRefOrGetter<number[]>
+	groups?: MaybeRefOrGetter<number[]>
+}
diff --git a/app/utils/strings.ts b/app/utils/strings.ts
index ebda00d..6422a23 100644
--- a/app/utils/strings.ts
+++ b/app/utils/strings.ts
@@ -15,19 +15,3 @@ export function capitalize(str: string): string {
 	if (!str) return ""
 	return str.charAt(0).toUpperCase() + str.slice(1)
 }
-
-/**
- * Returns up to the first two uppercase initials of a (whitespace-separated)
- * string. Useful for avatar fallbacks.
- *
- * Examples:
- *   getFirstLetters("Ivan")        -> "I"
- *   getFirstLetters("Ivan Petrov") -> "IP"
- *   getFirstLetters("")            -> ""
- */
-export function getFirstLetters(str: string): string {
-	if (!str) return ""
-	const words = str.split(" ")
-	if (words.length === 1 && words[0]) return words[0].charAt(0).toUpperCase()
-	return `${words[0]?.charAt(0).toUpperCase() ?? ""}${words[1]?.charAt(0).toUpperCase() ?? ""}`
-}
diff --git a/app/utils/tanstack-table.ts b/app/utils/tanstack-table.ts
deleted file mode 100644
index 0e856a0..0000000
--- a/app/utils/tanstack-table.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-import type { Updater } from "@tanstack/vue-table"
-import type { Ref } from "vue"
-
-export function valueUpdater<T extends Updater<unknown>>(updaterOrValue: T, ref: Ref) {
-	ref.value = typeof updaterOrValue === "function" ? updaterOrValue(ref.value) : updaterOrValue
-}
diff --git a/app/utils/tw-helper.ts b/app/utils/tw-helper.ts
deleted file mode 100644
index cf1414c..0000000
--- a/app/utils/tw-helper.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-/**
- * Utility function to return Tailwind CSS classes.
- */
-export const tw = <T extends TemplateStringsArray | string>(tailwindClasses: T) => tailwindClasses
diff --git a/nuxt.config.ts b/nuxt.config.ts
index 9f054d2..8e09318 100644
--- a/nuxt.config.ts
+++ b/nuxt.config.ts
@@ -88,9 +88,19 @@ export default defineNuxtConfig({
 		},
 	},
 	icon: {
-		provider: "iconify",
-		serverBundle: {
-			collections: ["lucide"],
+		// Move off the default /api/_nuxt_icon path so the service worker can
+		// distinguish Nuxt icon requests from the backend API at /api/* and apply
+		// different caching strategies to each.
+		localApiEndpoint: "/_icons",
+		// All 59 used icons are in the client bundle (18 KB) — no need to also
+		// bundle full collection JSONs (14 MB) into the Nitro server for SSR.
+		// ponytail: icons render client-side after hydration; add serverBundle
+		// if SSR icon rendering becomes a measurable CLS issue.
+		serverBundle: false,
+		clientBundle: {
+			// Scan .ts too — SCHEDULE_ICONS in app/constants/schedule.ts has
+			// lucide:building and lucide:user-check as string literals.
+			scan: { globInclude: ["app/**/*.{vue,ts}"] },
 		},
 	},
 	colorMode: {
@@ -117,6 +127,10 @@ export default defineNuxtConfig({
 		"/blocked": { robots: false, sitemap: false },
 		"/maintenance": { robots: false, sitemap: false },
 		"/share/**": { robots: false, sitemap: false },
+		// Service worker must never be cached by a CDN or proxy — browsers already
+		// check the SW byte-for-byte on every page load, but a stale cached response
+		// would prevent the browser from seeing an updated worker.
+		"/sw.js": { headers: { "cache-control": "no-cache, no-store, must-revalidate" } },
 	},
 	robots: {
 		sitemap: "/sitemap.xml",
diff --git a/package.json b/package.json
index aa54553..0f7ab5f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "mindenit-schedule",
-	"version": "1.0.0",
+	"version": "1.1.0",
 	"private": true,
 	"type": "module",
 	"scripts": {
@@ -9,7 +9,7 @@
 		"build": "nuxt build",
 		"dev": "nuxt dev",
 		"generate": "nuxt generate",
-		"preview": "nuxt preview",
+		"preview": "nuxt preview --port 3001",
 		"postinstall": "nuxt prepare",
 		"lint": "eslint .",
 		"lint:fix": "eslint . --fix",
@@ -48,7 +48,6 @@
 		"@tailwindcss/vite": "^4.3.2",
 		"@tanstack/query-persist-client-core": "^5.101.2",
 		"@tanstack/vue-query": "^5.101.2",
-		"@tanstack/vue-table": "^8.21.3",
 		"@unhead/vue": "^2.0.3 || ^3.0.0",
 		"@vueuse/core": "^14.3.0",
 		"@vueuse/nuxt": "^14.3.0",
@@ -77,6 +76,11 @@
 	"devDependencies": {
 		"@commitlint/cli": "^21.2.0",
 		"@commitlint/config-conventional": "^21.2.0",
+		"@iconify-json/brandico": "^1.2.3",
+		"@iconify-json/logos": "^1.2.13",
+		"@iconify-json/lucide": "^1.2.127",
+		"@iconify-json/mingcute": "^1.2.8",
+		"@iconify-json/ph": "^1.2.2",
 		"@popperjs/core": "^2.11.8",
 		"@yuta-inoue-ph/nuxt-vcalendar": "^1.1.4",
 		"eslint-config-prettier": "^10.1.8",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 714873e..b5382d2 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -52,9 +52,6 @@ importers:
       "@tanstack/vue-query":
         specifier: ^5.101.2
         version: 5.101.2(vue@3.5.39(typescript@5.9.3))
-      "@tanstack/vue-table":
-        specifier: ^8.21.3
-        version: 8.21.3(vue@3.5.39(typescript@5.9.3))
       "@unhead/vue":
         specifier: ^2.0.3 || ^3.0.0
         version: 2.1.15(vue@3.5.39(typescript@5.9.3))
@@ -134,6 +131,21 @@ importers:
       "@commitlint/config-conventional":
         specifier: ^21.2.0
         version: 21.2.0
+      "@iconify-json/brandico":
+        specifier: ^1.2.3
+        version: 1.2.3
+      "@iconify-json/logos":
+        specifier: ^1.2.13
+        version: 1.2.13
+      "@iconify-json/lucide":
+        specifier: ^1.2.127
+        version: 1.2.127
+      "@iconify-json/mingcute":
+        specifier: ^1.2.8
+        version: 1.2.8
+      "@iconify-json/ph":
+        specifier: ^1.2.2
+        version: 1.2.2
       "@popperjs/core":
         specifier: ^2.11.8
         version: 2.11.8
@@ -1419,12 +1431,42 @@ packages:
       }
     engines: { node: ">=18.18" }
 
+  "@iconify-json/brandico@1.2.3":
+    resolution:
+      {
+        integrity: sha512-frfO6v+vKBfYssfqHtZUMrewPuaDxZrjbp4lHXYpjwKC9gx4CFQkY94tboHk6iqsHuyTgt4cKXHt3KjUEzjgMg==,
+      }
+
   "@iconify-json/carbon@1.2.23":
     resolution:
       {
         integrity: sha512-7apXetbRmEiWDXIQyikFJZyq7pCVBKHYRzmeLdtT7wWoHYdWHwnFcBAzpuLoSh+ZEAfXZapSWEe8iuS6dUqf+Q==,
       }
 
+  "@iconify-json/logos@1.2.13":
+    resolution:
+      {
+        integrity: sha512-Up54ZnIuiuBgGAsuzhR1nvKqwq8VE6YM3XLwVB6IgY+7NAasz6WKu9Ay5hGfAkfuOKowodfwDC8ozReEBYrWRg==,
+      }
+
+  "@iconify-json/lucide@1.2.127":
+    resolution:
+      {
+        integrity: sha512-7KuCCpkly00kefna4wEnCr8l2HFRkbn4mD4zRib8wCSbrBmnR/l57ExpU6j5jv/Bo+qHpWuHpDtcqceQ0ptArw==,
+      }
+
+  "@iconify-json/mingcute@1.2.8":
+    resolution:
+      {
+        integrity: sha512-J8VXpRwTpx5yzOzyhx3T4IXnfXIKTWFl3rZ9okcW4c+NMMuwkLvdmM4rkjB83tnYIhg5+kkeMpmw8tvSnxd4rQ==,
+      }
+
+  "@iconify-json/ph@1.2.2":
+    resolution:
+      {
+        integrity: sha512-PgkEZNtqa8hBGjHXQa4pMwZa93hmfu8FUSjs/nv4oUU6yLsgv+gh9nu28Kqi8Fz9CCVu4hj1MZs9/60J57IzFw==,
+      }
+
   "@iconify/collections@1.0.707":
     resolution:
       {
@@ -7704,6 +7746,7 @@ packages:
         integrity: sha512-XoMjdBOwe/esVgEvLmNsD3IRHkm7fbKIUGvrleloJXUZgDHig2IPWNniv+GwjyJXzuNqVjlr5+4yVUZjycJwfQ==,
       }
     engines: { node: ^18.18.0 || ^20.9.0 || >=21.1.0 }
+    deprecated: This version is no longer supported. Please see https://eslint.org/version-support for other options.
     hasBin: true
     peerDependencies:
       jiti: "*"
@@ -13150,10 +13193,30 @@ snapshots:
 
   "@humanwhocodes/retry@0.4.3": {}
 
+  "@iconify-json/brandico@1.2.3":
+    dependencies:
+      "@iconify/types": 2.0.0
+
   "@iconify-json/carbon@1.2.23":
     dependencies:
       "@iconify/types": 2.0.0
 
+  "@iconify-json/logos@1.2.13":
+    dependencies:
+      "@iconify/types": 2.0.0
+
+  "@iconify-json/lucide@1.2.127":
+    dependencies:
+      "@iconify/types": 2.0.0
+
+  "@iconify-json/mingcute@1.2.8":
+    dependencies:
+      "@iconify/types": 2.0.0
+
+  "@iconify-json/ph@1.2.2":
+    dependencies:
+      "@iconify/types": 2.0.0
+
   "@iconify/collections@1.0.707":
     dependencies:
       "@iconify/types": 2.0.0
diff --git a/public/sw.js b/public/sw.js
new file mode 100644
index 0000000..9f22585
--- /dev/null
+++ b/public/sw.js
@@ -0,0 +1,154 @@
+/**
+ * Mindenit Schedule — Service Worker
+ *
+ * Strategies:
+ *   navigate requests  → NetworkFirst (shell), falls back to cached exact URL then "/"
+ *   /_nuxt/, /_fonts/  → CacheFirst  (content-hashed, immutable)
+ *   /_icons/           → StaleWhileRevalidate (icon bundles, server-rendered)
+ *   /api/              → bypass      (TanStack IDB owns all schedule data)
+ *   everything else    → bypass
+ *
+ * ponytail: CACHE_VERSION bump required when SW logic changes; activating a new
+ * worker with a mismatched asset cache causes a white-screen for offline users
+ * until they regain connectivity.
+ */
+
+const CACHE_VERSION = "v3"
+const SHELL_CACHE = `mindenit-shell-${CACHE_VERSION}`
+const ASSET_CACHE = `mindenit-assets-${CACHE_VERSION}`
+// Max static-asset entries so old deploy chunks don't accumulate indefinitely.
+// ponytail: FIFO trim, upgrade to LRU if 300 measurably causes issues.
+const ASSET_CACHE_MAX = 300
+
+// ── Install ──────────────────────────────────────────────────────────────────
+
+self.addEventListener("install", (event) => {
+	event.waitUntil(
+		caches
+			.open(SHELL_CACHE)
+			// Pre-cache the app shell so offline works even on the very first
+			// navigation before the user has loaded any route.
+			.then((cache) => cache.add("/"))
+			.then(() => self.skipWaiting())
+	)
+})
+
+// ── Activate ─────────────────────────────────────────────────────────────────
+
+self.addEventListener("activate", (event) => {
+	event.waitUntil(
+		caches
+			.keys()
+			.then((keys) =>
+				Promise.all(
+					keys
+						.filter((k) => k !== SHELL_CACHE && k !== ASSET_CACHE)
+						.map((k) => caches.delete(k))
+				)
+			)
+			.then(() => self.clients.claim())
+	)
+})
+
+// ── Fetch ─────────────────────────────────────────────────────────────────────
+
+self.addEventListener("fetch", (event) => {
+	const { request } = event
+	const url = new URL(request.url)
+
+	// Only intercept GET requests on the same origin.
+	if (request.method !== "GET" || url.origin !== location.origin) return
+
+	const path = url.pathname
+
+	// /api/* — never touch; TanStack Query + IndexedDB own schedule freshness.
+	if (path.startsWith("/api/")) return
+
+	if (request.mode === "navigate") {
+		event.respondWith(networkFirstShell(request))
+		return
+	}
+
+	// Content-hashed assets: /_nuxt/, /_fonts/ — immutable, cache forever.
+	if (path.startsWith("/_nuxt/") || path.startsWith("/_fonts/")) {
+		event.respondWith(cacheFirstAsset(request))
+		return
+	}
+
+	// Icon bundles: /_icons/ — serve stale, revalidate in background.
+	if (path.startsWith("/_icons/")) {
+		event.respondWith(staleWhileRevalidate(request, ASSET_CACHE))
+		return
+	}
+})
+
+// ── Strategies ────────────────────────────────────────────────────────────────
+
+async function networkFirstShell(request) {
+	const cache = await caches.open(SHELL_CACHE)
+	// Key by pathname only — query params (view, date, schedule, type) are read
+	// client-side by useUrlState after hydration, so different URLs share the
+	// same shell HTML. Prevents unbounded entry growth per query-string combo.
+	const key = new URL(request.url).pathname
+	try {
+		const response = await fetch(request)
+		if (response.ok) cache.put(key, response.clone())
+		return response
+	} catch {
+		// Network failed — try the exact path, then fall back to root shell.
+		const cached = (await cache.match(key)) ?? (await cache.match("/"))
+		if (cached) return cached
+		return new Response("Offline — no cached shell available", {
+			status: 503,
+			headers: { "Content-Type": "text/plain" },
+		})
+	}
+}
+
+async function cacheFirstAsset(request) {
+	const cache = await caches.open(ASSET_CACHE)
+	const cached = await cache.match(request)
+	if (cached) return cached
+
+	try {
+		const response = await fetch(request)
+		if (response.ok) {
+			cache.put(request, response.clone())
+			trimCache(cache, ASSET_CACHE_MAX)
+		}
+		return response
+	} catch {
+		return new Response("Asset unavailable offline", {
+			status: 503,
+			headers: { "Content-Type": "text/plain" },
+		})
+	}
+}
+
+async function staleWhileRevalidate(request, cacheName) {
+	const cache = await caches.open(cacheName)
+	const cached = await cache.match(request)
+
+	const fetchPromise = fetch(request)
+		.then((response) => {
+			if (response.ok) cache.put(request, response.clone())
+			return response
+		})
+		.catch(
+			() =>
+				new Response("Resource unavailable offline", {
+					status: 503,
+					headers: { "Content-Type": "text/plain" },
+				})
+		)
+
+	return cached ?? fetchPromise
+}
+
+// Trim oldest entries beyond `max` to prevent unbounded growth.
+async function trimCache(cache, max) {
+	const keys = await cache.keys()
+	if (keys.length > max) {
+		await Promise.all(keys.slice(0, keys.length - max).map((k) => cache.delete(k)))
+	}
+}