diff --git a/client/src/app/App.tsx b/client/src/app/App.tsx
index 342aca6..7cb4180 100644
--- a/client/src/app/App.tsx
+++ b/client/src/app/App.tsx
@@ -1,10 +1,7 @@
 import { BrowserRouter, Navigate, Route, Routes } from 'react-router-dom'
 import { MainLayout } from '@/app/layout/MainLayout'
 import { AppProviders } from '@/app/providers/AppProviders'
-import { AdminPage } from '@/pages/admin'
-import { AdminOrdersPage } from '@/pages/admin-orders'
-import { AdminReviewsPage } from '@/pages/admin-reviews'
-import { AdminUsersPage } from '@/pages/admin-users'
+import { AdminLayoutPage } from '@/pages/admin-layout'
 import { AuthPage } from '@/pages/auth'
 import { CartPage } from '@/pages/cart'
 import { CheckoutPage } from '@/pages/checkout'
@@ -19,10 +16,7 @@ export function App() {
         <MainLayout>
           <Routes>
             <Route path="/" element={<HomePage />} />
-            <Route path="/admin" element={<AdminPage />} />
-            <Route path="/admin/orders" element={<AdminOrdersPage />} />
-            <Route path="/admin/reviews" element={<AdminReviewsPage />} />
-            <Route path="/admin/users" element={<AdminUsersPage />} />
+            <Route path="/admin/*" element={<AdminLayoutPage />} />
             <Route path="/auth" element={<AuthPage />} />
             <Route path="/cart" element={<CartPage />} />
             <Route path="/checkout" element={<CheckoutPage />} />
diff --git a/client/src/app/layout/AppHeader.tsx b/client/src/app/layout/AppHeader.tsx
index 716a24d..02a30f5 100644
--- a/client/src/app/layout/AppHeader.tsx
+++ b/client/src/app/layout/AppHeader.tsx
@@ -3,6 +3,7 @@ import AccountCircleOutlinedIcon from '@mui/icons-material/AccountCircleOutlined
 import DarkModeOutlinedIcon from '@mui/icons-material/DarkModeOutlined'
 import LightModeOutlinedIcon from '@mui/icons-material/LightModeOutlined'
 import MenuOutlinedIcon from '@mui/icons-material/MenuOutlined'
+import ShoppingCartOutlinedIcon from '@mui/icons-material/ShoppingCartOutlined'
 import AppBar from '@mui/material/AppBar'
 import Badge from '@mui/material/Badge'
 import Box from '@mui/material/Box'
@@ -19,12 +20,15 @@ import Select from '@mui/material/Select'
 import type { SelectChangeEvent } from '@mui/material/Select'
 import { useTheme } from '@mui/material/styles'
 import Toolbar from '@mui/material/Toolbar'
+import Tooltip from '@mui/material/Tooltip'
 import Typography from '@mui/material/Typography'
 import useMediaQuery from '@mui/material/useMediaQuery'
+import { useQuery } from '@tanstack/react-query'
 import { useUnit } from 'effector-react'
 import { Link as RouterLink, useNavigate } from 'react-router-dom'
 import type { ColorScheme } from '@/app/providers/theme-controller'
 import { useThemeController } from '@/app/providers/theme-controller'
+import { fetchMyCart } from '@/entities/cart/api/cart-api'
 import { STORE_NAME } from '@/shared/config'
 import { $user, logout, tokenSet } from '@/shared/model/auth'
 import { BearLogo } from '@/shared/ui/BearLogo'
@@ -33,7 +37,6 @@ type NavItem = { label: string; to: string }
 
 const navItems: NavItem[] = [
   { label: 'Каталог', to: '/' },
-  { label: 'Корзина', to: '/cart' },
   { label: 'Админка', to: '/admin' },
 ]
 
@@ -166,6 +169,14 @@ export function AppHeader() {
   const user = useUnit($user)
   const navigate = useNavigate()
 
+  const cartQuery = useQuery({
+    queryKey: ['me', 'cart'],
+    queryFn: fetchMyCart,
+    enabled: Boolean(user),
+  })
+
+  const cartCount = cartQuery.data?.items?.length ?? 0
+
   const [userAnchorEl, setUserAnchorEl] = useState<null | HTMLElement>(null)
   const userMenuOpen = Boolean(userAnchorEl)
 
@@ -238,6 +249,25 @@ export function AppHeader() {
               </Button>
             ))}
 
+          <Tooltip title={user ? 'Корзина' : 'Авторизуйтесь для совершения покупок'}>
+            <span>
+              <IconButton
+                color="inherit"
+                sx={{ ml: 1 }}
+                disabled={!user}
+                onClick={() => {
+                  if (!user) navigate('/auth')
+                  else navigate('/cart')
+                }}
+                aria-label="Корзина"
+              >
+                <Badge color="secondary" badgeContent={user ? cartCount : 0} invisible={!user || cartCount === 0}>
+                  <ShoppingCartOutlinedIcon />
+                </Badge>
+              </IconButton>
+            </span>
+          </Tooltip>
+
           <IconButton color="inherit" onClick={openUserMenu} sx={{ ml: 1 }} aria-label="Пользователь">
             <Badge
               variant="dot"
@@ -300,6 +330,14 @@ export function AppHeader() {
                 {i.label}
               </Button>
             ))}
+            <Button
+              variant="text"
+              onClick={() => go(user ? '/cart' : '/auth')}
+              sx={{ justifyContent: 'flex-start' }}
+              disabled={!user}
+            >
+              Корзина
+            </Button>
             <Button variant="text" onClick={() => go(user ? '/me' : '/auth')} sx={{ justifyContent: 'flex-start' }}>
               {user ? 'Профиль' : 'Вход / регистрация'}
             </Button>
diff --git a/client/src/entities/product/model/types.ts b/client/src/entities/product/model/types.ts
index e0c6c9b..fa22da1 100644
--- a/client/src/entities/product/model/types.ts
+++ b/client/src/entities/product/model/types.ts
@@ -11,7 +11,7 @@ export type Product = {
   slug: string
   shortDescription: string | null
   description: string | null
-  quantity?: number | null
+  quantity: number
   materials?: string[]
   priceCents: number
   imageUrl: string | null
diff --git a/client/src/entities/product/ui/ProductCard.tsx b/client/src/entities/product/ui/ProductCard.tsx
index f0fd060..2ecfbca 100644
--- a/client/src/entities/product/ui/ProductCard.tsx
+++ b/client/src/entities/product/ui/ProductCard.tsx
@@ -117,6 +117,14 @@ export function ProductCard({ product, mediaHeight = 200, actions }: Props) {
       <CardContent sx={{ flexGrow: 1 }}>
         <Stack spacing={1}>
           {product.category && <Chip label={product.category.name} size="small" />}
+          {!product.inStock && (
+            <Chip
+              label={`Под заказ · ${product.leadTimeDays ?? '—'} дн.`}
+              size="small"
+              variant="outlined"
+              color="warning"
+            />
+          )}
           <Typography
             variant="h6"
             component={RouterLink}
@@ -126,7 +134,7 @@ export function ProductCard({ product, mediaHeight = 200, actions }: Props) {
             {product.title}
           </Typography>
           {(product.materials?.length ?? 0) > 0 && (
-            <Stack direction="row" spacing={1} useFlexGap flexWrap="wrap">
+            <Stack direction="row" spacing={1} useFlexGap sx={{ flexWrap: 'wrap' }}>
               {materials.map((m) => (
                 <Chip key={m} label={m} size="small" variant="outlined" />
               ))}
diff --git a/client/src/features/cart/toggle-cart-icon/index.ts b/client/src/features/cart/toggle-cart-icon/index.ts
new file mode 100644
index 0000000..8a884df
--- /dev/null
+++ b/client/src/features/cart/toggle-cart-icon/index.ts
@@ -0,0 +1 @@
+export { ToggleCartIcon } from './ui/ToggleCartIcon'
diff --git a/client/src/features/cart/toggle-cart-icon/ui/ToggleCartIcon.tsx b/client/src/features/cart/toggle-cart-icon/ui/ToggleCartIcon.tsx
new file mode 100644
index 0000000..4eb2ed8
--- /dev/null
+++ b/client/src/features/cart/toggle-cart-icon/ui/ToggleCartIcon.tsx
@@ -0,0 +1,62 @@
+import AddShoppingCartOutlinedIcon from '@mui/icons-material/AddShoppingCartOutlined'
+import ShoppingCartOutlinedIcon from '@mui/icons-material/ShoppingCartOutlined'
+import ShoppingCartRoundedIcon from '@mui/icons-material/ShoppingCartRounded'
+import IconButton from '@mui/material/IconButton'
+import Tooltip from '@mui/material/Tooltip'
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
+import { useUnit } from 'effector-react'
+import { useNavigate } from 'react-router-dom'
+import { addToCart, fetchMyCart, removeCartItem } from '@/entities/cart/api/cart-api'
+import { $user } from '@/shared/model/auth'
+
+export function ToggleCartIcon(props: { productId: string; size?: 'small' | 'medium' }) {
+  const { productId, size = 'small' } = props
+  const user = useUnit($user)
+  const qc = useQueryClient()
+  const navigate = useNavigate()
+
+  const cartQuery = useQuery({
+    queryKey: ['me', 'cart'],
+    queryFn: fetchMyCart,
+    enabled: Boolean(user),
+  })
+
+  const existing = cartQuery.data?.items.find((x) => x.product.id === productId) ?? null
+  const inCart = Boolean(existing)
+
+  const addMut = useMutation({
+    mutationFn: () => addToCart({ productId, qty: 1 }),
+    onSuccess: () => void qc.invalidateQueries({ queryKey: ['me', 'cart'] }),
+  })
+
+  const removeMut = useMutation({
+    mutationFn: () => removeCartItem(existing!.id),
+    onSuccess: () => void qc.invalidateQueries({ queryKey: ['me', 'cart'] }),
+  })
+
+  const disabled = !user
+  const busy = addMut.isPending || removeMut.isPending
+
+  const onClick = (e: React.MouseEvent) => {
+    e.preventDefault()
+    e.stopPropagation()
+    if (!user) {
+      navigate('/auth')
+      return
+    }
+    if (inCart) removeMut.mutate()
+    else addMut.mutate()
+  }
+
+  const tooltip = !user ? 'Авторизуйтесь для совершения покупок' : inCart ? 'Убрать из корзины' : 'В корзину'
+
+  return (
+    <Tooltip title={tooltip}>
+      <span>
+        <IconButton size={size} onClick={onClick} disabled={disabled || busy} aria-label={tooltip}>
+          {user ? inCart ? <ShoppingCartRoundedIcon /> : <AddShoppingCartOutlinedIcon /> : <ShoppingCartOutlinedIcon />}
+        </IconButton>
+      </span>
+    </Tooltip>
+  )
+}
diff --git a/client/src/pages/admin-layout/index.ts b/client/src/pages/admin-layout/index.ts
new file mode 100644
index 0000000..c7320cf
--- /dev/null
+++ b/client/src/pages/admin-layout/index.ts
@@ -0,0 +1 @@
+export { AdminLayoutPage } from './ui/AdminLayoutPage'
diff --git a/client/src/pages/admin-layout/ui/AdminLayoutPage.tsx b/client/src/pages/admin-layout/ui/AdminLayoutPage.tsx
new file mode 100644
index 0000000..7ce779b
--- /dev/null
+++ b/client/src/pages/admin-layout/ui/AdminLayoutPage.tsx
@@ -0,0 +1,127 @@
+import type { ReactNode } from 'react'
+import { useMemo, useState } from 'react'
+import AssignmentOutlinedIcon from '@mui/icons-material/AssignmentOutlined'
+import MenuOutlinedIcon from '@mui/icons-material/MenuOutlined'
+import PeopleOutlinedIcon from '@mui/icons-material/PeopleOutlined'
+import RateReviewOutlinedIcon from '@mui/icons-material/RateReviewOutlined'
+import StorefrontOutlinedIcon from '@mui/icons-material/StorefrontOutlined'
+import Box from '@mui/material/Box'
+import Divider from '@mui/material/Divider'
+import Drawer from '@mui/material/Drawer'
+import IconButton from '@mui/material/IconButton'
+import List from '@mui/material/List'
+import ListItemButton from '@mui/material/ListItemButton'
+import ListItemIcon from '@mui/material/ListItemIcon'
+import ListItemText from '@mui/material/ListItemText'
+import Stack from '@mui/material/Stack'
+import { useTheme } from '@mui/material/styles'
+import Typography from '@mui/material/Typography'
+import useMediaQuery from '@mui/material/useMediaQuery'
+import { Navigate, Route, Routes, useLocation, useNavigate } from 'react-router-dom'
+import { AdminPage } from '@/pages/admin'
+import { AdminOrdersPage } from '@/pages/admin-orders'
+import { AdminReviewsPage } from '@/pages/admin-reviews'
+import { AdminUsersPage } from '@/pages/admin-users'
+
+type NavItem = {
+  to: string
+  label: string
+  icon: ReactNode
+}
+
+export function AdminLayoutPage() {
+  const navigate = useNavigate()
+  const location = useLocation()
+  const theme = useTheme()
+  const isMobile = useMediaQuery(theme.breakpoints.down('md'))
+  const [mobileOpen, setMobileOpen] = useState(false)
+
+  const navItems: NavItem[] = useMemo(
+    () => [
+      { to: '/admin', label: 'Товары', icon: <StorefrontOutlinedIcon /> },
+      { to: '/admin/orders', label: 'Заказы', icon: <AssignmentOutlinedIcon /> },
+      { to: '/admin/reviews', label: 'Отзывы', icon: <RateReviewOutlinedIcon /> },
+      { to: '/admin/users', label: 'Пользователи', icon: <PeopleOutlinedIcon /> },
+    ],
+    [],
+  )
+
+  const activeTo =
+    navItems.find((x) => location.pathname === x.to)?.to ??
+    navItems.find((x) => location.pathname.startsWith(`${x.to}/`))?.to ??
+    null
+
+  const nav = (
+    <Box sx={{ width: 280, maxWidth: '85vw' }}>
+      <Box sx={{ p: 2 }}>
+        <Typography variant="subtitle1" sx={{ fontWeight: 700 }}>
+          Админка
+        </Typography>
+        <Typography variant="body2" color="text.secondary">
+          Управление магазином
+        </Typography>
+      </Box>
+      <Divider />
+      <List disablePadding>
+        {navItems.map((i) => (
+          <ListItemButton
+            key={i.to}
+            selected={activeTo === i.to}
+            onClick={() => {
+              navigate(i.to)
+              setMobileOpen(false)
+            }}
+          >
+            <ListItemIcon>{i.icon}</ListItemIcon>
+            <ListItemText primary={i.label} />
+          </ListItemButton>
+        ))}
+      </List>
+    </Box>
+  )
+
+  return (
+    <Stack direction={{ xs: 'column', md: 'row' }} spacing={3} sx={{ alignItems: 'flex-start' }}>
+      {isMobile ? (
+        <>
+          <Stack direction="row" spacing={1} sx={{ width: '100%', alignItems: 'center' }}>
+            <IconButton onClick={() => setMobileOpen(true)} aria-label="Открыть меню админки">
+              <MenuOutlinedIcon />
+            </IconButton>
+            <Typography variant="h5" sx={{ fontWeight: 700 }}>
+              Админка
+            </Typography>
+          </Stack>
+          <Drawer open={mobileOpen} onClose={() => setMobileOpen(false)} ModalProps={{ keepMounted: true }}>
+            {nav}
+          </Drawer>
+        </>
+      ) : (
+        <Box
+          sx={{
+            position: 'sticky',
+            top: 88,
+            alignSelf: 'flex-start',
+            border: 1,
+            borderColor: 'divider',
+            borderRadius: 2,
+            bgcolor: 'background.paper',
+            overflow: 'hidden',
+          }}
+        >
+          {nav}
+        </Box>
+      )}
+
+      <Box sx={{ flexGrow: 1, minWidth: 0, width: '100%' }}>
+        <Routes>
+          <Route index element={<AdminPage />} />
+          <Route path="orders" element={<AdminOrdersPage />} />
+          <Route path="reviews" element={<AdminReviewsPage />} />
+          <Route path="users" element={<AdminUsersPage />} />
+          <Route path="*" element={<Navigate to="/admin" replace />} />
+        </Routes>
+      </Box>
+    </Stack>
+  )
+}
diff --git a/client/src/pages/admin-orders/ui/AdminOrdersPage.tsx b/client/src/pages/admin-orders/ui/AdminOrdersPage.tsx
index dc512fc..135ea5c 100644
--- a/client/src/pages/admin-orders/ui/AdminOrdersPage.tsx
+++ b/client/src/pages/admin-orders/ui/AdminOrdersPage.tsx
@@ -20,7 +20,6 @@ import TextField from '@mui/material/TextField'
 import Typography from '@mui/material/Typography'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { Controller, useForm } from 'react-hook-form'
-import { Link as RouterLink } from 'react-router-dom'
 import {
   fetchAdminOrder,
   fetchAdminOrders,
@@ -104,17 +103,9 @@ export function AdminOrdersPage() {
 
   return (
     <Box>
-      <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ mb: 2, alignItems: { sm: 'center' } }}>
-        <Typography variant="h4" sx={{ flexGrow: 1 }}>
-          Админка — заказы
-        </Typography>
-        <Button component={RouterLink} to="/admin" variant="outlined">
-          Товары
-        </Button>
-        <Button component={RouterLink} to="/admin/reviews" variant="outlined">
-          Отзывы
-        </Button>
-      </Stack>
+      <Typography variant="h4" sx={{ mb: 2 }}>
+        Заказы
+      </Typography>
 
       <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
         Введите API-токен из <code>ADMIN_API_TOKEN</code> (сохраняется в sessionStorage).
@@ -222,7 +213,7 @@ export function AdminOrdersPage() {
                 #{detail.id.slice(-8)} · {detail.user.email} · {detail.status} · {formatPriceRub(detail.totalCents)}
               </Typography>
 
-              <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} alignItems={{ sm: 'center' }}>
+              <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ alignItems: { sm: 'center' } }}>
                 <FormControl size="small" sx={{ minWidth: 240 }}>
                   <InputLabel id="next-status-label">Сменить статус</InputLabel>
                   <Select
@@ -264,7 +255,7 @@ export function AdminOrdersPage() {
                   {detail.messages.length === 0 && <Typography color="text.secondary">Нет сообщений.</Typography>}
                 </Stack>
 
-                <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} alignItems={{ sm: 'flex-end' }}>
+                <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ alignItems: { sm: 'flex-end' } }}>
                   <TextField
                     label="Ответ админа"
                     value={msg}
diff --git a/client/src/pages/admin-reviews/ui/AdminReviewsPage.tsx b/client/src/pages/admin-reviews/ui/AdminReviewsPage.tsx
index abe33a8..4c64add 100644
--- a/client/src/pages/admin-reviews/ui/AdminReviewsPage.tsx
+++ b/client/src/pages/admin-reviews/ui/AdminReviewsPage.tsx
@@ -13,7 +13,6 @@ import TextField from '@mui/material/TextField'
 import Typography from '@mui/material/Typography'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { Controller, useForm } from 'react-hook-form'
-import { Link as RouterLink } from 'react-router-dom'
 import { fetchAdminReviews, moderateReview } from '@/entities/review/api/admin-review-api'
 import { clearAdminToken, getAdminToken, setAdminToken } from '@/shared/lib/admin-token'
 
@@ -57,17 +56,9 @@ export function AdminReviewsPage() {
 
   return (
     <Box>
-      <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ mb: 2, alignItems: { sm: 'center' } }}>
-        <Typography variant="h4" sx={{ flexGrow: 1 }}>
-          Админка — отзывы
-        </Typography>
-        <Button component={RouterLink} to="/admin" variant="outlined">
-          Товары
-        </Button>
-        <Button component={RouterLink} to="/admin/orders" variant="outlined">
-          Заказы
-        </Button>
-      </Stack>
+      <Typography variant="h4" sx={{ mb: 2 }}>
+        Отзывы
+      </Typography>
 
       <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
         Введите API-токен из <code>ADMIN_API_TOKEN</code>.
diff --git a/client/src/pages/admin/ui/AdminPage.tsx b/client/src/pages/admin/ui/AdminPage.tsx
index c6b86d4..775688c 100644
--- a/client/src/pages/admin/ui/AdminPage.tsx
+++ b/client/src/pages/admin/ui/AdminPage.tsx
@@ -22,7 +22,6 @@ import TextField from '@mui/material/TextField'
 import Typography from '@mui/material/Typography'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { Controller, useForm } from 'react-hook-form'
-import { Link as RouterLink } from 'react-router-dom'
 import {
   createCategory,
   createProduct,
@@ -328,15 +327,6 @@ export function AdminPage() {
             <Button variant="outlined" onClick={() => setCatOpen(true)}>
               Новая категория
             </Button>
-            <Button component={RouterLink} to="/admin/orders" variant="outlined">
-              Заказы
-            </Button>
-            <Button component={RouterLink} to="/admin/reviews" variant="outlined">
-              Отзывы
-            </Button>
-            <Button component={RouterLink} to="/admin/users" variant="outlined">
-              Пользователи
-            </Button>
           </Stack>
 
           {productsQuery.isError && (
diff --git a/client/src/pages/cart/ui/CartPage.tsx b/client/src/pages/cart/ui/CartPage.tsx
index 4d056be..7488cd8 100644
--- a/client/src/pages/cart/ui/CartPage.tsx
+++ b/client/src/pages/cart/ui/CartPage.tsx
@@ -7,6 +7,7 @@ import Button from '@mui/material/Button'
 import Divider from '@mui/material/Divider'
 import IconButton from '@mui/material/IconButton'
 import Stack from '@mui/material/Stack'
+import Tooltip from '@mui/material/Tooltip'
 import Typography from '@mui/material/Typography'
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
 import { useUnit } from 'effector-react'
@@ -62,57 +63,104 @@ export function CartPage() {
 
       {items.length > 0 && (
         <Stack spacing={2}>
-          {items.map((x) => (
-            <Box
-              key={x.id}
-              sx={{
-                border: 1,
-                borderColor: 'divider',
-                borderRadius: 2,
-                p: 2,
-                bgcolor: 'background.paper',
-              }}
-            >
-              <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} alignItems={{ sm: 'center' }}>
-                <Box sx={{ flexGrow: 1 }}>
-                  <Typography sx={{ fontWeight: 700 }}>{x.product.title}</Typography>
-                  <Typography color="text.secondary" variant="body2">
-                    {formatPriceRub(x.product.priceCents)} · {x.qty} шт.
-                  </Typography>
+          {items.map((x) =>
+            (() => {
+              const available = x.product.inStock ? x.product.quantity : 1
+              const canInc = x.qty < available
+              const over = x.qty > available
+              return (
+                <Box
+                  key={x.id}
+                  sx={{
+                    border: 1,
+                    borderColor: over ? 'error.light' : 'divider',
+                    borderRadius: 2,
+                    p: 2,
+                    bgcolor: over ? 'error.50' : 'background.paper',
+                  }}
+                >
+                  <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ alignItems: { sm: 'center' } }}>
+                    <Box sx={{ flexGrow: 1 }}>
+                      <Typography sx={{ fontWeight: 700 }}>{x.product.title}</Typography>
+                      <Typography color="text.secondary" variant="body2">
+                        {formatPriceRub(x.product.priceCents)} · {x.qty} шт. · Доступно: {available}
+                      </Typography>
+                      {!x.product.inStock && (
+                        <Typography color="text.secondary" variant="caption">
+                          Под заказ — доставка после изготовления
+                        </Typography>
+                      )}
+                      {over && (
+                        <Typography color="error" variant="caption" sx={{ display: 'block', mt: 0.5 }}>
+                          Недостаточно товара. Уменьшите количество до {available}.
+                        </Typography>
+                      )}
+                    </Box>
+
+                    <Stack
+                      direction="row"
+                      spacing={0.5}
+                      sx={{
+                        bgcolor: 'background.default',
+                        borderRadius: 999,
+                        px: 0.75,
+                        height: 40,
+                        alignItems: 'center',
+                      }}
+                    >
+                      <IconButton
+                        onClick={() => qtyMut.mutate({ id: x.id, qty: Math.max(0, x.qty - 1) })}
+                        disabled={qtyMut.isPending}
+                        aria-label="Уменьшить количество"
+                        size="small"
+                        sx={{ width: 32, height: 32 }}
+                      >
+                        <RemoveIcon />
+                      </IconButton>
+                      <Typography
+                        sx={{
+                          minWidth: 28,
+                          textAlign: 'center',
+                          lineHeight: 1,
+                          fontWeight: 700,
+                          fontVariantNumeric: 'tabular-nums',
+                        }}
+                      >
+                        {x.qty}
+                      </Typography>
+                      <Tooltip title={!canInc ? `Доступно: ${available}` : 'Увеличить количество'}>
+                        <span>
+                          <IconButton
+                            onClick={() => qtyMut.mutate({ id: x.id, qty: x.qty + 1 })}
+                            disabled={qtyMut.isPending || !canInc}
+                            aria-label="Увеличить количество"
+                            size="small"
+                            sx={{ width: 32, height: 32 }}
+                          >
+                            <AddIcon />
+                          </IconButton>
+                        </span>
+                      </Tooltip>
+
+                      <IconButton
+                        onClick={() => removeMut.mutate(x.id)}
+                        disabled={removeMut.isPending}
+                        aria-label="Удалить"
+                        size="small"
+                        sx={{ width: 32, height: 32 }}
+                      >
+                        <DeleteOutlineOutlinedIcon />
+                      </IconButton>
+                    </Stack>
+                  </Stack>
                 </Box>
-
-                <Stack direction="row" spacing={1} alignItems="center">
-                  <IconButton
-                    onClick={() => qtyMut.mutate({ id: x.id, qty: Math.max(0, x.qty - 1) })}
-                    disabled={qtyMut.isPending}
-                    aria-label="Уменьшить количество"
-                  >
-                    <RemoveIcon />
-                  </IconButton>
-                  <Typography sx={{ minWidth: 24, textAlign: 'center' }}>{x.qty}</Typography>
-                  <IconButton
-                    onClick={() => qtyMut.mutate({ id: x.id, qty: x.qty + 1 })}
-                    disabled={qtyMut.isPending}
-                    aria-label="Увеличить количество"
-                  >
-                    <AddIcon />
-                  </IconButton>
-
-                  <IconButton
-                    onClick={() => removeMut.mutate(x.id)}
-                    disabled={removeMut.isPending}
-                    aria-label="Удалить"
-                  >
-                    <DeleteOutlineOutlinedIcon />
-                  </IconButton>
-                </Stack>
-              </Stack>
-            </Box>
-          ))}
+              )
+            })(),
+          )}
 
           <Divider />
 
-          <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} alignItems={{ sm: 'center' }}>
+          <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ alignItems: { sm: 'center' } }}>
             <Typography variant="h6" sx={{ flexGrow: 1 }}>
               Итого: {formatPriceRub(total)}
             </Typography>
diff --git a/client/src/pages/checkout/ui/CheckoutPage.tsx b/client/src/pages/checkout/ui/CheckoutPage.tsx
index bce14b9..3c435ad 100644
--- a/client/src/pages/checkout/ui/CheckoutPage.tsx
+++ b/client/src/pages/checkout/ui/CheckoutPage.tsx
@@ -37,8 +37,11 @@ export function CheckoutPage() {
     enabled: Boolean(user),
   })
 
+  const defaultAddressId = addressesQuery.data?.items?.find((a) => a.isDefault)?.id ?? ''
+  const selectedAddressId = addressId || defaultAddressId
+
   const createMut = useMutation({
-    mutationFn: () => createOrder({ addressId, comment: comment.trim() || null }),
+    mutationFn: () => createOrder({ addressId: selectedAddressId, comment: comment.trim() || null }),
     onSuccess: async (res) => {
       await qc.invalidateQueries({ queryKey: ['me', 'cart'] })
       navigate(`/me/orders/${res.orderId}`, { replace: true })
@@ -60,8 +63,8 @@ export function CheckoutPage() {
   const items = cartQuery.data?.items ?? []
   const total = items.reduce((s, x) => s + x.product.priceCents * x.qty, 0)
   const addresses = addressesQuery.data?.items ?? []
-
-  const defaultAddr = addresses.find((a) => a.isDefault)
+  const hasOverLimit = items.some((x) => x.qty > (x.product.inStock ? x.product.quantity : 1))
+  const hasMadeToOrder = items.some((x) => !x.product.inStock)
 
   return (
     <Box>
@@ -80,12 +83,45 @@ export function CheckoutPage() {
       )}
 
       <Stack spacing={2} sx={{ maxWidth: 720 }}>
+        {items.length > 0 && (
+          <Box sx={{ border: 1, borderColor: 'divider', borderRadius: 2, p: 2, bgcolor: 'background.paper' }}>
+            <Typography sx={{ fontWeight: 700, mb: 1 }}>Позиции</Typography>
+            <Stack spacing={0.5}>
+              {items.map((x) => {
+                const available = x.product.inStock ? x.product.quantity : 1
+                const over = x.qty > available
+                return (
+                  <Typography key={x.id} color={over ? 'error' : 'text.primary'}>
+                    {x.product.title}: {x.qty} шт. (доступно {available})
+                  </Typography>
+                )
+              })}
+            </Stack>
+          </Box>
+        )}
+
+        {hasOverLimit && (
+          <Alert severity="warning">
+            Некоторые позиции превышают доступное количество. Вернитесь в{' '}
+            <Typography component={RouterLink} to="/cart" sx={{ textDecoration: 'underline' }}>
+              корзину
+            </Typography>{' '}
+            и скорректируйте количество.
+          </Alert>
+        )}
+
+        {hasMadeToOrder && (
+          <Alert severity="info">
+            В заказе есть товары «под заказ». Доставка будет после изготовления (срок указан в карточке товара).
+          </Alert>
+        )}
+
         <FormControl size="small" fullWidth>
           <InputLabel id="addr-label">Адрес доставки</InputLabel>
           <Select
             labelId="addr-label"
             label="Адрес доставки"
-            value={addressId || (defaultAddr?.id ?? '')}
+            value={selectedAddressId}
             onChange={(e) => setAddressId(String(e.target.value))}
           >
             {addresses.map((a) => (
@@ -119,7 +155,9 @@ export function CheckoutPage() {
 
         <Button
           variant="contained"
-          disabled={items.length === 0 || addresses.length === 0 || createMut.isPending}
+          disabled={
+            items.length === 0 || addresses.length === 0 || !selectedAddressId || hasOverLimit || createMut.isPending
+          }
           onClick={() => createMut.mutate()}
         >
           Создать заказ
diff --git a/client/src/pages/home/ui/HomePage.tsx b/client/src/pages/home/ui/HomePage.tsx
index 4c79ad8..0a0b7c5 100644
--- a/client/src/pages/home/ui/HomePage.tsx
+++ b/client/src/pages/home/ui/HomePage.tsx
@@ -21,7 +21,7 @@ import Typography from '@mui/material/Typography'
 import { useQuery } from '@tanstack/react-query'
 import { fetchCategories, fetchPublicProducts } from '@/entities/product/api/product-api'
 import { ProductCard } from '@/entities/product/ui/ProductCard'
-import { AddToCartButton } from '@/features/cart/add-to-cart'
+import { ToggleCartIcon } from '@/features/cart/toggle-cart-icon'
 
 export function HomePage() {
   const [categorySlug, setCategorySlug] = useState<string>('')
@@ -124,8 +124,7 @@ export function HomePage() {
         <Stack
           direction={{ xs: 'column', md: 'row' }}
           spacing={2}
-          alignItems={{ md: 'center' }}
-          sx={{ flexWrap: { md: 'wrap' } }}
+          sx={{ alignItems: { md: 'center' }, flexWrap: { md: 'wrap' } }}
         >
           <FormControl sx={{ minWidth: 220 }} size="small">
             <InputLabel id="category-filter-label">Категория</InputLabel>
@@ -159,9 +158,7 @@ export function HomePage() {
         <Stack
           direction={{ xs: 'column', sm: 'row' }}
           spacing={1.5}
-          alignItems={{ sm: 'center' }}
-          justifyContent="space-between"
-          flexWrap="wrap"
+          sx={{ alignItems: { sm: 'center' }, justifyContent: 'space-between', flexWrap: 'wrap' }}
         >
           <Button variant="text" onClick={() => setMoreOpen((v) => !v)} sx={{ alignSelf: { xs: 'flex-start' } }}>
             {moreOpen ? 'Скрыть фильтры' : 'Фильтры и сортировка'}
@@ -188,8 +185,7 @@ export function HomePage() {
           <Stack
             direction={{ xs: 'column', md: 'row' }}
             spacing={2}
-            alignItems={{ md: 'center' }}
-            sx={{ mt: 2, flexWrap: { md: 'wrap' } }}
+            sx={{ mt: 2, alignItems: { md: 'center' }, flexWrap: { md: 'wrap' } }}
           >
             <FormControl sx={{ minWidth: 220 }} size="small">
               <InputLabel id="sort-label">Сортировка</InputLabel>
@@ -316,16 +312,12 @@ export function HomePage() {
           <Grid container spacing={2}>
             {products.map((p) => (
               <Grid size={{ xs: 12, sm: 6, md: 4 }} key={p.id}>
-                <ProductCard
-                  product={p}
-                  mediaHeight={mediaHeight}
-                  actions={<AddToCartButton productId={p.id} variant="contained" size="small" />}
-                />
+                <ProductCard product={p} mediaHeight={mediaHeight} actions={<ToggleCartIcon productId={p.id} />} />
               </Grid>
             ))}
           </Grid>
 
-          <Stack direction="row" justifyContent="center" sx={{ mt: 3 }}>
+          <Stack direction="row" sx={{ mt: 3, justifyContent: 'center' }}>
             <Pagination
               page={page}
               count={totalPages}
diff --git a/client/src/pages/me/ui/MeLayoutPage.tsx b/client/src/pages/me/ui/MeLayoutPage.tsx
index d362101..46c583e 100644
--- a/client/src/pages/me/ui/MeLayoutPage.tsx
+++ b/client/src/pages/me/ui/MeLayoutPage.tsx
@@ -93,7 +93,7 @@ export function MeLayoutPage() {
     <Stack direction={{ xs: 'column', md: 'row' }} spacing={3} sx={{ alignItems: 'flex-start' }}>
       {isMobile ? (
         <>
-          <Stack direction="row" spacing={1} alignItems="center" sx={{ width: '100%' }}>
+          <Stack direction="row" spacing={1} sx={{ width: '100%', alignItems: 'center' }}>
             <IconButton onClick={() => setMobileOpen(true)} aria-label="Открыть меню профиля">
               <MenuOutlinedIcon />
             </IconButton>
diff --git a/client/src/pages/me/ui/sections/AddressesPage.tsx b/client/src/pages/me/ui/sections/AddressesPage.tsx
index eabb537..50d12e9 100644
--- a/client/src/pages/me/ui/sections/AddressesPage.tsx
+++ b/client/src/pages/me/ui/sections/AddressesPage.tsx
@@ -182,7 +182,7 @@ export function AddressesPage() {
               bgcolor: 'background.paper',
             }}
           >
-            <Stack direction={{ xs: 'column', sm: 'row' }} spacing={1} alignItems={{ sm: 'center' }}>
+            <Stack direction={{ xs: 'column', sm: 'row' }} spacing={1} sx={{ alignItems: { sm: 'center' } }}>
               <Typography sx={{ fontWeight: 700, flexGrow: 1 }}>{a.label?.trim() ? a.label : 'Адрес'}</Typography>
               {a.isDefault && <Chip label="По умолчанию" color="primary" size="small" />}
             </Stack>
diff --git a/client/src/pages/me/ui/sections/OrderDetailPage.tsx b/client/src/pages/me/ui/sections/OrderDetailPage.tsx
index 69eff69..d912713 100644
--- a/client/src/pages/me/ui/sections/OrderDetailPage.tsx
+++ b/client/src/pages/me/ui/sections/OrderDetailPage.tsx
@@ -60,7 +60,7 @@ export function OrderDetailPage() {
 
   return (
     <Box>
-      <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} alignItems={{ sm: 'center' }} sx={{ mb: 2 }}>
+      <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ mb: 2, alignItems: { sm: 'center' } }}>
         <Box sx={{ flexGrow: 1 }}>
           <Typography variant="h4">Заказ #{order.id.slice(-6)}</Typography>
           <Typography color="text.secondary">Статус: {order.status}</Typography>
@@ -77,7 +77,7 @@ export function OrderDetailPage() {
           </Typography>
           <Stack spacing={1}>
             {order.items.map((i) => (
-              <Stack key={i.id} direction="row" spacing={2} alignItems="center">
+              <Stack key={i.id} direction="row" spacing={2} sx={{ alignItems: 'center' }}>
                 <Box sx={{ flexGrow: 1 }}>
                   <Typography sx={{ fontWeight: 700 }}>{i.titleSnapshot}</Typography>
                   <Typography color="text.secondary" variant="body2">
@@ -155,7 +155,7 @@ export function OrderDetailPage() {
             {order.messages.length === 0 && <Typography color="text.secondary">Пока сообщений нет.</Typography>}
           </Stack>
 
-          <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} alignItems={{ sm: 'flex-end' }}>
+          <Stack direction={{ xs: 'column', sm: 'row' }} spacing={2} sx={{ alignItems: { sm: 'flex-end' } }}>
             <TextField
               label="Сообщение"
               value={text}
diff --git a/client/src/pages/me/ui/sections/OrdersPage.tsx b/client/src/pages/me/ui/sections/OrdersPage.tsx
index 5c27168..7f7dc67 100644
--- a/client/src/pages/me/ui/sections/OrdersPage.tsx
+++ b/client/src/pages/me/ui/sections/OrdersPage.tsx
@@ -40,7 +40,7 @@ export function OrdersPage() {
               bgcolor: 'background.paper',
             }}
           >
-            <Stack direction={{ xs: 'column', sm: 'row' }} spacing={1} alignItems={{ sm: 'center' }}>
+            <Stack direction={{ xs: 'column', sm: 'row' }} spacing={1} sx={{ alignItems: { sm: 'center' } }}>
               <Box sx={{ flexGrow: 1 }}>
                 <Typography sx={{ fontWeight: 700 }}>Заказ #{o.id.slice(-6)}</Typography>
                 <Typography color="text.secondary" variant="body2">
diff --git a/client/src/pages/product/ui/ProductPage.tsx b/client/src/pages/product/ui/ProductPage.tsx
index 25f6e9f..a73e361 100644
--- a/client/src/pages/product/ui/ProductPage.tsx
+++ b/client/src/pages/product/ui/ProductPage.tsx
@@ -14,7 +14,7 @@ import { Swiper, SwiperSlide } from 'swiper/react'
 import 'swiper/css'
 import 'swiper/css/navigation'
 import { fetchPublicProduct } from '@/entities/product/api/product-api'
-import { AddToCartButton } from '@/features/cart/add-to-cart'
+import { ToggleCartIcon } from '@/features/cart/toggle-cart-icon'
 import { formatPriceRub } from '@/shared/lib/format-price'
 
 export function ProductPage() {
@@ -137,7 +137,13 @@ export function ProductPage() {
           {formatPriceRub(p.priceCents)}
         </Typography>
 
-        <AddToCartButton productId={p.id} variant="contained" sx={{ alignSelf: 'flex-start' }} />
+        <ToggleCartIcon productId={p.id} size="medium" />
+
+        {!p.inStock && (
+          <Alert severity="info">
+            Этот товар изготавливается под заказ. Доставка будет после изготовления (~{p.leadTimeDays ?? '—'} дн.).
+          </Alert>
+        )}
 
         {p.description ? (
           <Typography sx={{ whiteSpace: 'pre-wrap' }}>{p.description}</Typography>
diff --git a/client/src/shared/model/auth.ts b/client/src/shared/model/auth.ts
index be0e0dd..6c2df82 100644
--- a/client/src/shared/model/auth.ts
+++ b/client/src/shared/model/auth.ts
@@ -74,8 +74,13 @@ sample({
   target: $user,
 })
 
+let tokenPersistInitialized = false
 $token.watch((t) => {
   try {
+    if (!tokenPersistInitialized) {
+      tokenPersistInitialized = true
+      return
+    }
     if (!t) localStorage.removeItem(TOKEN_KEY)
     else localStorage.setItem(TOKEN_KEY, t)
   } catch {
diff --git a/server/prisma/migrations/20260429145229_quantity_required/migration.sql b/server/prisma/migrations/20260429145229_quantity_required/migration.sql
new file mode 100644
index 0000000..1d5bedf
--- /dev/null
+++ b/server/prisma/migrations/20260429145229_quantity_required/migration.sql
@@ -0,0 +1,27 @@
+-- RedefineTables
+PRAGMA defer_foreign_keys=ON;
+PRAGMA foreign_keys=OFF;
+CREATE TABLE "new_Product" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "title" TEXT NOT NULL,
+    "slug" TEXT NOT NULL,
+    "shortDescription" TEXT,
+    "description" TEXT,
+    "quantity" INTEGER NOT NULL DEFAULT 0,
+    "materials" TEXT NOT NULL DEFAULT '[]',
+    "priceCents" INTEGER NOT NULL,
+    "imageUrl" TEXT,
+    "published" BOOLEAN NOT NULL DEFAULT false,
+    "inStock" BOOLEAN NOT NULL DEFAULT true,
+    "leadTimeDays" INTEGER,
+    "categoryId" TEXT NOT NULL,
+    "createdAt" DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" DATETIME NOT NULL,
+    CONSTRAINT "Product_categoryId_fkey" FOREIGN KEY ("categoryId") REFERENCES "Category" ("id") ON DELETE CASCADE ON UPDATE CASCADE
+);
+INSERT INTO "new_Product" ("categoryId", "createdAt", "description", "id", "imageUrl", "inStock", "leadTimeDays", "materials", "priceCents", "published", "quantity", "shortDescription", "slug", "title", "updatedAt") SELECT "categoryId", "createdAt", "description", "id", "imageUrl", "inStock", "leadTimeDays", "materials", "priceCents", "published", coalesce("quantity", 0) AS "quantity", "shortDescription", "slug", "title", "updatedAt" FROM "Product";
+DROP TABLE "Product";
+ALTER TABLE "new_Product" RENAME TO "Product";
+CREATE UNIQUE INDEX "Product_slug_key" ON "Product"("slug");
+PRAGMA foreign_keys=ON;
+PRAGMA defer_foreign_keys=OFF;
diff --git a/server/prisma/schema.prisma b/server/prisma/schema.prisma
index bf4a8a3..a5214f7 100644
--- a/server/prisma/schema.prisma
+++ b/server/prisma/schema.prisma
@@ -22,8 +22,8 @@ model Product {
   slug        String   @unique
   shortDescription String?
   description String?
-  /// Количество на складе (если null — не ведём учёт)
-  quantity    Int?
+  /// Количество на складе
+  quantity    Int      @default(0)
   /// Материалы (список, например: ["хлопок","дерево"])
   materials   String   @default("[]")
   /// Цена в копейках (целое число, без дробной части)
diff --git a/server/src/routes/api/admin-products.js b/server/src/routes/api/admin-products.js
index b42483e..e8352ae 100644
--- a/server/src/routes/api/admin-products.js
+++ b/server/src/routes/api/admin-products.js
@@ -89,8 +89,14 @@ export async function registerAdminProductRoutes(
         return
       }
 
-      let quantity = null
-      if (!(body.quantity === undefined || body.quantity === null || body.quantity === '')) {
+      let quantity = 0
+      if (!inStock) {
+        quantity = 1
+      } else {
+        if (body.quantity === undefined || body.quantity === null || body.quantity === '') {
+          reply.code(400).send({ error: 'Укажите количество' })
+          return
+        }
         const n = Number(body.quantity)
         if (!Number.isFinite(n) || n < 0) {
           reply.code(400).send({ error: 'Некорректное количество (quantity ≥ 0)' })
@@ -162,15 +168,15 @@ export async function registerAdminProductRoutes(
       if (body.quantity !== undefined) {
         const v = body.quantity
         if (v === null || v === '') {
-          data.quantity = null
-        } else {
-          const n = Number(v)
-          if (!Number.isFinite(n) || n < 0) {
-            reply.code(400).send({ error: 'Некорректное количество (quantity ≥ 0)' })
-            return
-          }
-          data.quantity = Math.floor(n)
+          reply.code(400).send({ error: 'Укажите количество' })
+          return
         }
+        const n = Number(v)
+        if (!Number.isFinite(n) || n < 0) {
+          reply.code(400).send({ error: 'Некорректное количество (quantity ≥ 0)' })
+          return
+        }
+        data.quantity = Math.floor(n)
       }
       if (body.materials !== undefined) {
         data.materials = JSON.stringify(parseMaterialsInput(body.materials))
@@ -209,6 +215,9 @@ export async function registerAdminProductRoutes(
       if (nextInStock && data.leadTimeDays !== undefined) {
         data.leadTimeDays = null
       }
+      if (!nextInStock) {
+        data.quantity = 1
+      }
 
       const imagesUpdate =
         body.imageUrls !== undefined
diff --git a/server/src/routes/api/public-catalog.js b/server/src/routes/api/public-catalog.js
index 16ef720..1208c78 100644
--- a/server/src/routes/api/public-catalog.js
+++ b/server/src/routes/api/public-catalog.js
@@ -29,7 +29,7 @@ export async function registerPublicCatalogRoutes(fastify, { mapProductForApi }
     const priceMaxParsed = typeof priceMaxRaw === 'string' ? Number(priceMaxRaw) : Number(priceMaxRaw)
     const priceMax = Number.isFinite(priceMaxParsed) && priceMaxParsed >= 0 ? Math.floor(priceMaxParsed) : null
 
-    const where = { published: true }
+    const where = { published: true, quantity: { gt: 0 } }
     if (typeof categorySlug === 'string' && categorySlug.length > 0) {
       where.category = { slug: categorySlug }
     }
@@ -70,7 +70,7 @@ export async function registerPublicCatalogRoutes(fastify, { mapProductForApi }
   fastify.get('/api/products/:id', async (request, reply) => {
     const { id } = request.params
     const product = await prisma.product.findFirst({
-      where: { id, published: true },
+      where: { id, published: true, quantity: { gt: 0 } },
       include: { category: true, images: { orderBy: { sort: 'asc' } } },
     })
     if (!product) {
diff --git a/server/src/routes/auth.js b/server/src/routes/auth.js
index fa43bbc..69f118a 100644
--- a/server/src/routes/auth.js
+++ b/server/src/routes/auth.js
@@ -393,10 +393,15 @@ export async function registerAuthRoutes(fastify) {
       const product = await prisma.product.findFirst({ where: { id: productId, published: true } })
       if (!product) return reply.code(404).send({ error: 'Товар не найден' })
 
+      const available = product.inStock ? product.quantity : 1
+      const existing = await prisma.cartItem.findUnique({ where: { userId_productId: { userId, productId } } })
+      const nextQty = (existing?.qty ?? 0) + Math.floor(qty)
+      if (nextQty > available) return reply.code(409).send({ error: `Доступно: ${available} шт.` })
+
       const item = await prisma.cartItem.upsert({
         where: { userId_productId: { userId, productId } },
-        update: { qty: { increment: Math.floor(qty) } },
-        create: { userId, productId, qty: Math.floor(qty) },
+        update: { qty: nextQty },
+        create: { userId, productId, qty: nextQty },
       })
       return reply.code(201).send({ item })
     },
@@ -412,7 +417,7 @@ export async function registerAuthRoutes(fastify) {
       const qty = Number(qtyRaw)
       if (!Number.isFinite(qty) || qty < 0) return reply.code(400).send({ error: 'qty должен быть ≥ 0' })
 
-      const existing = await prisma.cartItem.findFirst({ where: { id, userId } })
+      const existing = await prisma.cartItem.findFirst({ where: { id, userId }, include: { product: true } })
       if (!existing) return reply.code(404).send({ error: 'Позиция корзины не найдена' })
 
       if (qty === 0) {
@@ -420,7 +425,11 @@ export async function registerAuthRoutes(fastify) {
         return reply.code(204).send()
       }
 
-      const updated = await prisma.cartItem.update({ where: { id }, data: { qty: Math.floor(qty) } })
+      const available = existing.product.inStock ? existing.product.quantity : 1
+      const nextQty = Math.floor(qty)
+      if (nextQty > available) return reply.code(409).send({ error: `Доступно: ${available} шт.` })
+
+      const updated = await prisma.cartItem.update({ where: { id }, data: { qty: nextQty } })
       return { item: updated }
     },
   )
@@ -460,6 +469,13 @@ export async function registerAuthRoutes(fastify) {
       })
       if (cartItems.length === 0) return reply.code(400).send({ error: 'Корзина пуста' })
 
+      for (const ci of cartItems) {
+        const available = ci.product.inStock ? ci.product.quantity : 1
+        if (ci.qty > available) {
+          return reply.code(409).send({ error: `Недостаточно товара: "${ci.product.title}". Доступно: ${available} шт.` })
+        }
+      }
+
       const itemsPayload = cartItems.map((ci) => ({
         productId: ci.productId,
         qty: ci.qty,
@@ -479,28 +495,50 @@ export async function registerAuthRoutes(fastify) {
         lng: address.lng,
       })
 
-      const created = await prisma.$transaction(async (tx) => {
-        const order = await tx.order.create({
-          data: {
-            userId,
-            status: 'PENDING_PAYMENT',
-            totalCents,
-            currency: 'RUB',
-            addressSnapshotJson,
-            comment: comment && comment.length ? comment : null,
-            items: {
-              create: itemsPayload.map((i) => ({
-                productId: i.productId,
-                qty: i.qty,
-                titleSnapshot: i.titleSnapshot,
-                priceCentsSnapshot: i.priceCentsSnapshot,
-              })),
+      let created
+      try {
+        created = await prisma.$transaction(async (tx) => {
+          for (const ci of cartItems) {
+            if (!ci.product.inStock) continue
+
+            const res = await tx.product.updateMany({
+              where: { id: ci.productId, quantity: { gte: ci.qty } },
+              data: { quantity: { decrement: ci.qty } },
+            })
+            if (res.count !== 1) {
+              throw new Error(`Недостаточно товара: "${ci.product.title}"`)
+            }
+
+            const p = await tx.product.findUnique({ where: { id: ci.productId }, select: { quantity: true } })
+            if (p && p.quantity === 0) {
+              await tx.product.update({ where: { id: ci.productId }, data: { published: false } })
+            }
+          }
+
+          const order = await tx.order.create({
+            data: {
+              userId,
+              status: 'PENDING_PAYMENT',
+              totalCents,
+              currency: 'RUB',
+              addressSnapshotJson,
+              comment: comment && comment.length ? comment : null,
+              items: {
+                create: itemsPayload.map((i) => ({
+                  productId: i.productId,
+                  qty: i.qty,
+                  titleSnapshot: i.titleSnapshot,
+                  priceCentsSnapshot: i.priceCentsSnapshot,
+                })),
+              },
             },
-          },
+          })
+          await tx.cartItem.deleteMany({ where: { userId } })
+          return order
         })
-        await tx.cartItem.deleteMany({ where: { userId } })
-        return order
-      })
+      } catch (e) {
+        return reply.code(409).send({ error: (e instanceof Error && e.message) || 'Недостаточно товара' })
+      }
 
       return reply.code(201).send({ orderId: created.id })
     },