diff --git a/client/src/components/Layout.tsx b/client/src/components/Layout.tsx
index 4e35167..212332c 100644
--- a/client/src/components/Layout.tsx
+++ b/client/src/components/Layout.tsx
@@ -3,14 +3,12 @@ import { useQuery, useQueryClient } from "@tanstack/react-query";
 import { useLocation } from "wouter";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 import { Button } from "@/components/ui/button";
-import { LogOut, Store, Menu, AlertTriangle, Smartphone, Monitor } from "lucide-react";
+import { LogOut, Store, Menu, AlertTriangle } from "lucide-react";
 import { useAuthUnified } from "@/hooks/useAuthUnified";
 import { useIsMobile } from "@/hooks/use-mobile";
 import { useScreenSize } from "@/hooks/use-screen-size";
-import { usePhoneMode } from "@/hooks/use-phone-mode";
 import { StoreProvider } from "@/contexts/StoreContext";
 import Sidebar from "./Sidebar";
-import PhoneBottomNav from "./PhoneBottomNav";
 import WeatherWidget from "./WeatherWidget";
 import DateWidget from "./DateWidget";
 import type { Group } from "@shared/schema";
@@ -26,7 +24,6 @@ export default function Layout({ children }: LayoutProps) {
   const queryClient = useQueryClient();
   const isMobile = useIsMobile();
   const { screenSize, isMobileOrTablet, isTablet } = useScreenSize();
-  const { isPhoneMode, setPhoneMode, canUsePhoneMode } = usePhoneMode();
   
   const [selectedStoreId, setSelectedStoreId] = useState<number | null>(() => {
     // Restaurer le selectedStoreId depuis localStorage si disponible
@@ -125,9 +122,9 @@ export default function Layout({ children }: LayoutProps) {
 
   return (
     <StoreProvider value={{ selectedStoreId, setSelectedStoreId, stores, sidebarCollapsed, setSidebarCollapsed, mobileMenuOpen, setMobileMenuOpen, storeInitialized }}>
-      <div className={`layout-container flex bg-gray-50 ${isPhoneMode ? 'phone-mode' : ''}`}>
+      <div className="layout-container flex bg-gray-50">
         {/* Mobile overlay for normal mode */}
-        {!isPhoneMode && isMobile && mobileMenuOpen && (
+        {isMobile && mobileMenuOpen && (
           <div 
             className="fixed inset-0 bg-black bg-opacity-50 z-40"
             onClick={() => setMobileMenuOpen(false)}
@@ -135,25 +132,21 @@ export default function Layout({ children }: LayoutProps) {
         )}
         
         {/* Sidebar for normal mode */}
-        {!isPhoneMode && <Sidebar />}
+        <Sidebar />
         
         <main className={`flex-1 flex flex-col h-full ${
           // Ajustement des marges selon le mode
-          isPhoneMode 
-            ? 'ml-0 mb-20' // Mode téléphone : pas de marge gauche, marge bas pour bottom nav
-            : isMobile 
+          isMobile 
               ? 'ml-0' 
               : (isTablet && !sidebarCollapsed) ? 'ml-48' : 'ml-0'
         }`}>
           {/* Header with mobile menu and store selector */}
-          <header className={`${
-            isPhoneMode ? 'h-12' : 'h-16'
-          } bg-white border-b border-gray-200 flex items-center justify-between ${
+          <header className={`h-16 bg-white border-b border-gray-200 flex items-center justify-between ${
             isMobileOrTablet ? 'px-3' : 'px-6'
           }`}>
             <div className="flex items-center gap-2 sm:gap-4 min-w-0 flex-1">
               {/* Mobile menu button (only in normal mode) */}
-              {!isPhoneMode && isMobile && (
+              {isMobile && (
                 <Button
                   variant="ghost"
                   size="sm"
@@ -169,47 +162,13 @@ export default function Layout({ children }: LayoutProps) {
               <div className={`flex items-center ${
                 isMobile ? 'gap-1' : 'gap-3'
               } min-w-0`}>
-                {/* En mode téléphone, affichage simplifié */}
-                {isPhoneMode ? (
-                  <div className="flex items-center gap-2">
-                    <WeatherWidget />
-                    {/* Phone mode toggle button */}
-                    <Button
-                      variant="ghost"
-                      size="sm"
-                      onClick={() => setPhoneMode(!isPhoneMode)}
-                      className="min-h-[44px] min-w-[44px] p-2 flex-shrink-0"
-                      data-testid="button-phone-mode-toggle"
-                      title="Basculer vers le mode normal"
-                    >
-                      <Monitor className="h-4 w-4 text-blue-600" />
-                    </Button>
-                  </div>
-                ) : (
-                  <>
-                    <WeatherWidget />
-                    {!isMobile && <DateWidget />}
-                    
-                    {/* Phone mode toggle button */}
-                    {canUsePhoneMode && (
-                      <Button
-                        variant="ghost"
-                        size="sm"
-                        onClick={() => setPhoneMode(!isPhoneMode)}
-                        className="min-h-[44px] min-w-[44px] p-2 flex-shrink-0"
-                        data-testid="button-phone-mode-toggle"
-                        title="Basculer vers le mode téléphone"
-                      >
-                        <Smartphone className="h-4 w-4 text-gray-600" />
-                      </Button>
-                    )}
-                  </>
-                )}
+                <WeatherWidget />
+                {!isMobile && <DateWidget />}
               </div>
             </div>
 
             {/* Store selector for admin, directeur, and manager - responsive */}
-            {!isPhoneMode && user && (user.role === 'admin' || user.role === 'directeur' || user.role === 'manager') && stores.length > 0 && (
+            {user && (user.role === 'admin' || user.role === 'directeur' || user.role === 'manager') && stores.length > 0 && (
               <div className="flex items-center gap-1 sm:gap-2 flex-shrink-0">
                 <Store className="h-4 w-4 text-gray-500 hidden sm:block" />
                 <Select
@@ -299,16 +258,12 @@ export default function Layout({ children }: LayoutProps) {
           )}
 
           <div className={`flex-1 bg-gray-50 h-full overflow-y-auto ${
-            isPhoneMode 
-              ? 'p-2' // Mode téléphone : padding réduit
-              : isMobileOrTablet ? 'p-3' : 'p-6'
+              isMobileOrTablet ? 'p-3' : 'p-6'
           }`}>
             {children}
           </div>
         </main>
         
-        {/* Bottom navigation for phone mode (only when authenticated) */}
-        {isPhoneMode && user && <PhoneBottomNav user={user} location={location} />}
       </div>
     </StoreProvider>
   );
diff --git a/client/src/index.css b/client/src/index.css
index 8ed9dc3..c06f5ad 100644
--- a/client/src/index.css
+++ b/client/src/index.css
@@ -64,11 +64,24 @@
     @apply font-sans antialiased bg-surface text-foreground;
     max-width: 100vw;
     height: 100%;
+    overflow-x: hidden;
   }
   
   #root {
     max-width: 100vw;
-    height: 100%;
+    min-height: 100%;
+    overflow-x: hidden;
+  }
+  
+  /* Éviter le débordement horizontal sur mobile */
+  * {
+    box-sizing: border-box;
+  }
+  
+  /* Forcer les conteneurs à ne pas déborder */
+  .container, .main-content, [data-testid*="task"] {
+    max-width: 100vw;
+    overflow-x: hidden;
   }
 
   /* Forcer la cohérence des largeurs de sidebar */
diff --git a/client/src/pages/Tasks.tsx b/client/src/pages/Tasks.tsx
index 4ddc565..93f15a5 100644
--- a/client/src/pages/Tasks.tsx
+++ b/client/src/pages/Tasks.tsx
@@ -1565,37 +1565,10 @@ export default function Tasks() {
 
 {/* Modal d'édition */}
       {showEditModal && selectedTask && (
-        <div style={{
-          position: 'fixed',
-          top: 0,
-          left: 0,
-          right: 0,
-          bottom: 0,
-          backgroundColor: 'rgba(0, 0, 0, 0.5)',
-          zIndex: 1000,
-          display: 'flex',
-          alignItems: 'center',
-          justifyContent: 'center'
-        }}>
-          <div style={{
-            backgroundColor: 'white',
-            borderRadius: '0px',
-            maxWidth: '600px',
-            width: '90%',
-            maxHeight: '90vh',
-            overflow: 'auto',
-            boxShadow: '0 25px 50px -12px rgba(0, 0, 0, 0.25)'
-          }}>
-            <div style={{
-              padding: '24px 24px 16px',
-              borderBottom: '1px solid #e5e7eb',
-              position: 'relative'
-            }}>
-              <h2 style={{
-                fontSize: '18px',
-                fontWeight: '600',
-                margin: '0'
-              }}>
+        <div className="fixed inset-0 bg-black bg-opacity-50 z-[1000] flex items-start sm:items-center justify-center p-4">
+          <div className="bg-white dark:bg-gray-800 rounded-lg max-w-full sm:max-w-2xl w-full max-h-[calc(100vh-2rem)] overflow-y-auto shadow-2xl">
+            <div className="p-6 pb-4 border-b border-gray-200 dark:border-gray-700 sticky top-0 bg-white dark:bg-gray-800">
+              <h2 className="text-lg font-semibold m-0 pr-10 dark:text-white">
                 Modifier la tâche
               </h2>
               <button
@@ -1603,21 +1576,7 @@ export default function Tasks() {
                   setShowEditModal(false);
                   setSelectedTask(null);
                 }}
-                style={{
-                  position: 'absolute',
-                  top: '16px',
-                  right: '16px',
-                  background: 'none',
-                  border: 'none',
-                  fontSize: '20px',
-                  cursor: 'pointer',
-                  padding: '4px',
-                  borderRadius: '0px',
-                  color: '#6b7280',
-                  transition: 'color 0.2s'
-                }}
-                onMouseEnter={(e) => (e.target as HTMLButtonElement).style.color = '#374151'}
-                onMouseLeave={(e) => (e.target as HTMLButtonElement).style.color = '#6b7280'}
+                className="absolute top-4 right-4 bg-transparent border-none text-xl cursor-pointer p-2 rounded text-gray-500 dark:text-gray-400 hover:text-gray-700 dark:hover:text-gray-300 transition-colors"
               >
                 ✕
               </button>
@@ -1637,86 +1596,32 @@ export default function Tasks() {
 
 {/* Modal de confirmation de suppression */}
       {showDeleteModal && taskToDelete && (
-        <div style={{
-          position: 'fixed',
-          top: 0,
-          left: 0,
-          right: 0,
-          bottom: 0,
-          backgroundColor: 'rgba(0, 0, 0, 0.5)',
-          zIndex: 1000,
-          display: 'flex',
-          alignItems: 'center',
-          justifyContent: 'center'
-        }}>
-          <div style={{
-            backgroundColor: 'white',
-            borderRadius: '0px',
-            maxWidth: '400px',
-            width: '90%',
-            padding: '24px',
-            boxShadow: '0 25px 50px -12px rgba(0, 0, 0, 0.25)'
-          }}>
-            <h2 style={{
-              fontSize: '18px',
-              fontWeight: '600',
-              margin: '0 0 16px 0',
-              color: '#dc2626',
-              display: 'flex',
-              alignItems: 'center',
-              gap: '8px'
-            }}>
+        <div className="fixed inset-0 bg-black bg-opacity-50 z-[1000] flex items-center justify-center p-4">
+          <div className="bg-white dark:bg-gray-800 rounded-lg max-w-sm w-full p-6 shadow-2xl mx-4">
+            <h2 className="text-lg font-semibold mb-4 text-red-600 dark:text-red-400 flex items-center gap-2">
               ⚠️ Confirmer la suppression
             </h2>
-            <div style={{ marginBottom: '24px' }}>
-              <p style={{
-                color: '#374151',
-                lineHeight: '1.5',
-                margin: '0 0 8px 0'
-              }}>
+            <div className="mb-6">
+              <p className="text-gray-700 dark:text-gray-300 leading-relaxed mb-2">
                 Êtes-vous sûr de vouloir supprimer la tâche "{taskToDelete.title}" ?
               </p>
-              <p style={{
-                fontSize: '14px',
-                color: '#6b7280',
-                margin: '0'
-              }}>
+              <p className="text-sm text-gray-500 dark:text-gray-400">
                 Cette action est irréversible.
               </p>
             </div>
-            <div style={{
-              display: 'flex',
-              gap: '12px',
-              justifyContent: 'flex-end'
-            }}>
+            <div className="flex gap-3 flex-col sm:flex-row">
               <button
                 onClick={() => {
                   setShowDeleteModal(false);
                   setTaskToDelete(null);
                 }}
-                style={{
-                  padding: '8px 16px',
-                  border: '1px solid #d1d5db',
-                  borderRadius: '0px',
-                  backgroundColor: 'white',
-                  cursor: 'pointer'
-                }}
+                className="px-4 py-2 border border-gray-300 dark:border-gray-600 rounded-md bg-white dark:bg-gray-700 text-gray-700 dark:text-gray-300 cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-600 order-2 sm:order-1"
               >
                 Annuler
               </button>
               <button 
                 onClick={handleConfirmDelete}
-                style={{
-                  padding: '8px 16px',
-                  border: 'none',
-                  borderRadius: '0px',
-                  backgroundColor: '#dc2626',
-                  color: 'white',
-                  cursor: 'pointer',
-                  display: 'flex',
-                  alignItems: 'center',
-                  gap: '8px'
-                }}
+                className="px-4 py-2 border-none rounded-md bg-red-600 text-white cursor-pointer hover:bg-red-700 flex items-center justify-center gap-2 order-1 sm:order-2"
               >
                 🗑️ Supprimer
               </button>