diff --git a/client/src/components/Administration.tsx b/client/src/components/Administration.tsx
index 17eef92..a286edd 100644
--- a/client/src/components/Administration.tsx
+++ b/client/src/components/Administration.tsx
@@ -7,6 +7,7 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/components/ui/table";
 import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger, DialogDescription } from "@/components/ui/dialog";
+import { AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent, AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle, AlertDialogTrigger } from "@/components/ui/alert-dialog";
 import { Form, FormControl, FormField, FormItem, FormLabel, FormMessage } from "@/components/ui/form";
 import { Badge } from "@/components/ui/badge";
 import { useForm } from "react-hook-form";
@@ -258,16 +259,12 @@ export default function Administration() {
     });
   };
 
-  const handleDeleteUser = async (user: User) => {
-    if (window.confirm(`Êtes-vous sûr de vouloir supprimer l'utilisateur "${user.username}" ?`)) {
-      await deleteUserMutation.mutateAsync(user.id);
-    }
+  const handleDeleteUser = (user: User) => {
+    deleteUserMutation.mutate(user.id);
   };
 
-  const handleDeleteStore = async (store: Store) => {
-    if (window.confirm(`Êtes-vous sûr de vouloir supprimer le magasin "${store.name}" ?`)) {
-      await deleteStoreMutation.mutateAsync(store.id);
-    }
+  const handleDeleteStore = (store: Store) => {
+    deleteStoreMutation.mutate(store.id);
   };
 
   const getRoleBadge = (role: string) => {
@@ -518,14 +515,38 @@ export default function Administration() {
                           >
                             <Edit className="h-4 w-4" />
                           </Button>
-                          <Button
-                            variant="ghost"
-                            size="sm"
-                            onClick={() => handleDeleteUser(user)}
-                            disabled={user.role === 'administrator'}
-                          >
-                            <Trash2 className="h-4 w-4 text-red-600" />
-                          </Button>
+                          <AlertDialog>
+                            <AlertDialogTrigger asChild>
+                              <Button
+                                variant="ghost"
+                                size="sm"
+                                disabled={user.role === 'administrator'}
+                              >
+                                <Trash2 className="h-4 w-4 text-red-600" />
+                              </Button>
+                            </AlertDialogTrigger>
+                            <AlertDialogContent>
+                              <AlertDialogHeader>
+                                <AlertDialogTitle>Confirmer la suppression</AlertDialogTitle>
+                                <AlertDialogDescription>
+                                  Êtes-vous sûr de vouloir supprimer l'utilisateur "{user.username}" ? Cette action est irréversible.
+                                  <br /><br />
+                                  <strong>Nom complet :</strong> {user.firstName} {user.lastName}<br />
+                                  <strong>Email :</strong> {user.email || "Non renseigné"}<br />
+                                  <strong>Rôle :</strong> {user.role}
+                                </AlertDialogDescription>
+                              </AlertDialogHeader>
+                              <AlertDialogFooter>
+                                <AlertDialogCancel>Annuler</AlertDialogCancel>
+                                <AlertDialogAction
+                                  onClick={() => handleDeleteUser(user)}
+                                  className="bg-red-600 hover:bg-red-700"
+                                >
+                                  Supprimer
+                                </AlertDialogAction>
+                              </AlertDialogFooter>
+                            </AlertDialogContent>
+                          </AlertDialog>
                         </div>
                       </TableCell>
                     </TableRow>
@@ -819,13 +840,37 @@ export default function Administration() {
                           >
                             <Edit className="h-4 w-4" />
                           </Button>
-                          <Button
-                            variant="ghost"
-                            size="sm"
-                            onClick={() => handleDeleteStore(store)}
-                          >
-                            <Trash2 className="h-4 w-4 text-red-600" />
-                          </Button>
+                          <AlertDialog>
+                            <AlertDialogTrigger asChild>
+                              <Button
+                                variant="ghost"
+                                size="sm"
+                              >
+                                <Trash2 className="h-4 w-4 text-red-600" />
+                              </Button>
+                            </AlertDialogTrigger>
+                            <AlertDialogContent>
+                              <AlertDialogHeader>
+                                <AlertDialogTitle>Confirmer la suppression</AlertDialogTitle>
+                                <AlertDialogDescription>
+                                  Êtes-vous sûr de vouloir supprimer le magasin "{store.name}" ? Cette action est irréversible.
+                                  <br /><br />
+                                  <strong>Adresse :</strong> {store.address || "Non renseignée"}<br />
+                                  <strong>Téléphone :</strong> {store.phone || "Non renseigné"}<br />
+                                  <strong>Email :</strong> {store.email || "Non renseigné"}
+                                </AlertDialogDescription>
+                              </AlertDialogHeader>
+                              <AlertDialogFooter>
+                                <AlertDialogCancel>Annuler</AlertDialogCancel>
+                                <AlertDialogAction
+                                  onClick={() => handleDeleteStore(store)}
+                                  className="bg-red-600 hover:bg-red-700"
+                                >
+                                  Supprimer
+                                </AlertDialogAction>
+                              </AlertDialogFooter>
+                            </AlertDialogContent>
+                          </AlertDialog>
                         </div>
                       </TableCell>
                     </TableRow>
diff --git a/client/src/components/SalesHistory.tsx b/client/src/components/SalesHistory.tsx
index 6527e7f..ea9c679 100644
--- a/client/src/components/SalesHistory.tsx
+++ b/client/src/components/SalesHistory.tsx
@@ -4,7 +4,8 @@ import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { Button } from '@/components/ui/button';
 import { Input } from '@/components/ui/input';
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from '@/components/ui/table';
-import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger } from '@/components/ui/dialog';
+import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger, DialogFooter, DialogDescription } from '@/components/ui/dialog';
+import { AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent, AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle, AlertDialogTrigger } from '@/components/ui/alert-dialog';
 import { useToast } from '@/hooks/use-toast';
 import { useStoreContext } from '@/hooks/useStoreContext';
 import { useAuth } from '@/hooks/useAuth';
@@ -70,10 +71,8 @@ export default function SalesHistory({ canDelete = false }: SalesHistoryProps) {
     },
   });
 
-  const handleDeleteSale = async (sale: Sale) => {
-    if (confirm(`Êtes-vous sûr de vouloir supprimer cette vente ?`)) {
-      deleteSaleMutation.mutate(sale.id);
-    }
+  const handleDeleteSale = (sale: Sale) => {
+    deleteSaleMutation.mutate(sale.id);
   };
 
   const exportToCSV = () => {
@@ -280,14 +279,38 @@ export default function SalesHistory({ canDelete = false }: SalesHistoryProps) {
                           </DialogContent>
                         </Dialog>
                         {canDelete && (
-                          <Button
-                            variant="ghost"
-                            size="sm"
-                            onClick={() => handleDeleteSale(sale)}
-                            disabled={deleteSaleMutation.isPending}
-                          >
-                            <Trash2 className="h-4 w-4 text-red-600" />
-                          </Button>
+                          <AlertDialog>
+                            <AlertDialogTrigger asChild>
+                              <Button
+                                variant="ghost"
+                                size="sm"
+                                disabled={deleteSaleMutation.isPending}
+                              >
+                                <Trash2 className="h-4 w-4 text-red-600" />
+                              </Button>
+                            </AlertDialogTrigger>
+                            <AlertDialogContent>
+                              <AlertDialogHeader>
+                                <AlertDialogTitle>Confirmer la suppression</AlertDialogTitle>
+                                <AlertDialogDescription>
+                                  Êtes-vous sûr de vouloir supprimer cette vente ? Cette action est irréversible.
+                                  <br /><br />
+                                  <strong>Client :</strong> {sale.nom} {sale.prenom}<br />
+                                  <strong>Article :</strong> {sale.typeArticle}<br />
+                                  <strong>Date :</strong> {formatDateTime(sale.timestamp!)}
+                                </AlertDialogDescription>
+                              </AlertDialogHeader>
+                              <AlertDialogFooter>
+                                <AlertDialogCancel>Annuler</AlertDialogCancel>
+                                <AlertDialogAction
+                                  onClick={() => handleDeleteSale(sale)}
+                                  className="bg-red-600 hover:bg-red-700"
+                                >
+                                  Supprimer
+                                </AlertDialogAction>
+                              </AlertDialogFooter>
+                            </AlertDialogContent>
+                          </AlertDialog>
                         )}
                       </div>
                     </TableCell>
diff --git a/replit.md b/replit.md
index 5c142b3..fe1423d 100644
--- a/replit.md
+++ b/replit.md
@@ -151,4 +151,11 @@ Preferred communication style: Simple, everyday language.
 - ✅ Generated default admin account (admin/admin123) for initial setup
 - ✅ Updated all components to work with database instead of local storage
 - ✅ Added session-based authentication with PostgreSQL session store
-- ✅ Implemented comprehensive API with proper validation and error handling
\ No newline at end of file
+- ✅ Implemented comprehensive API with proper validation and error handling
+
+### User Experience Improvements (January 9, 2025)
+- ✅ Fixed authentication flow issues with login/logout redirects
+- ✅ Replaced native browser confirm() dialogs with modern AlertDialog modals
+- ✅ Enhanced deletion confirmations in sales history and administration panels
+- ✅ Improved visual feedback with detailed confirmation dialogs showing item details
+- ✅ Added proper modal management with shadcn/ui AlertDialog components
\ No newline at end of file