diff --git a/memento-note/components/ai-chat.tsx b/memento-note/components/ai-chat.tsx
index d2c9acd..ca520d1 100644
--- a/memento-note/components/ai-chat.tsx
+++ b/memento-note/components/ai-chat.tsx
@@ -83,19 +83,24 @@ export function AIChat({ showFloatingTrigger = true }: { showFloatingTrigger?: b
       }
     }
 
-    await sendMessage(
-      { text },
-      {
-        body: {
-          tone: selectedTone,
-          chatScope,
-          notebookId: chatScope !== 'all' ? chatScope : undefined,
-          webSearch: webSearch && webSearchAvailable,
-          conversationId: convId,
-          language,
+    try {
+      await sendMessage(
+        { text },
+        {
+          body: {
+            tone: selectedTone,
+            chatScope,
+            notebookId: chatScope !== 'all' ? chatScope : undefined,
+            webSearch: webSearch && webSearchAvailable,
+            conversationId: convId,
+            language,
+          }
         }
-      }
-    )
+      )
+    } catch (error) {
+      console.error('Chat send error:', error)
+      toast.error(t('chat.assistantError') || 'Failed to send message')
+    }
   }
 
   const fetchHistory = async () => {
diff --git a/memento-note/components/chat/chat-container.tsx b/memento-note/components/chat/chat-container.tsx
index fac1e45..e7e9b1c 100644
--- a/memento-note/components/chat/chat-container.tsx
+++ b/memento-note/components/chat/chat-container.tsx
@@ -137,17 +137,22 @@ export function ChatContainer({ initialConversations, notebooks, webSearchAvaila
       }
     }
 
-    await sendMessage(
-      { text: content },
-      {
-        body: {
-          conversationId: convId,
-          notebookId: notebookId || selectedNotebook || undefined,
-          language,
-          webSearch: webSearchEnabled,
-        },
-      }
-    )
+    try {
+      await sendMessage(
+        { text: content },
+        {
+          body: {
+            conversationId: convId,
+            notebookId: notebookId || selectedNotebook || undefined,
+            language,
+            webSearch: webSearchEnabled,
+          },
+        }
+      )
+    } catch (error) {
+      console.error('Chat send error:', error)
+      toast.error(t('chat.assistantError') || 'Failed to send message')
+    }
   }
 
   const handleNewChat = () => {
diff --git a/memento-note/components/contextual-ai-chat.tsx b/memento-note/components/contextual-ai-chat.tsx
index 932e839..ea2ec0c 100644
--- a/memento-note/components/contextual-ai-chat.tsx
+++ b/memento-note/components/contextual-ai-chat.tsx
@@ -220,7 +220,12 @@ export function ContextualAIChat({
     const text = input.trim()
     if (!text || isLoading) return
     setInput('')
-    await sendMessage({ text }, { body: buildChatBody() })
+    try {
+      await sendMessage({ text }, { body: buildChatBody() })
+    } catch (error) {
+      console.error('Chat send error:', error)
+      toast.error(t('chat.assistantError') || 'Failed to send message')
+    }
   }
 
   // ── Action execution ────────────────────────────────────────────────────────
@@ -493,7 +498,7 @@ export function ContextualAIChat({
           <div className="flex items-start justify-between">
             <div className="min-w-0 space-y-2">
               <h2 className="font-serif text-xl font-medium text-[#1C1C1C] flex items-center gap-2 leading-tight">
-                <Sparkles className="h-[18px] w-[18px] shrink-0 text-[#D4A373]" />
+                <Sparkles className="h-[18px] w-[18px] shrink-0 text-memento-accent" />
                 IA Assistant
               </h2>
               <p className="text-[11px] text-[#1C1C1C]/60 uppercase tracking-wider font-medium opacity-60 truncate">
@@ -510,9 +515,12 @@ export function ContextualAIChat({
               </button>
               <button 
                 onClick={onClose}
-                className="p-1.5 hover:bg-white/40 rounded-full transition-colors text-[#1C1C1C]/40"
+                className="p-1.5 hover:bg-white/40 rounded-full transition-colors text-[#1C1C1C]/40 group"
               >
-                <ChevronRight size={20} />
+                <div className="relative w-5 h-5 flex items-center justify-center">
+                  <ChevronRight size={20} className="transition-all duration-200 group-hover:opacity-0 group-hover:scale-0" />
+                  <X size={18} className="absolute inset-0 m-auto opacity-0 scale-0 transition-all duration-200 group-hover:opacity-100 group-hover:scale-100" />
+                </div>
               </button>
             </div>
           </div>
@@ -534,7 +542,7 @@ export function ContextualAIChat({
             >
               {tab.label}
               {activeTab === tab.id && (
-                <motion.div layoutId="activeTab" className="absolute bottom-0 left-0 right-0 h-[2px] bg-[#75B2D6]" />
+                <motion.div layoutId="activeTab" className="absolute bottom-0 left-0 right-0 h-[2px] bg-memento-accent" />
               )}
             </button>
           ))}
@@ -562,7 +570,7 @@ export function ContextualAIChat({
           {resourcePreview && (
             <div className="absolute inset-0 z-20 flex flex-col bg-[#FDFDFE]/95 backdrop-blur-md animate-in fade-in slide-in-from-top-4 duration-300">
               <div className="px-6 py-4 border-b border-border/40 flex items-center justify-between shrink-0">
-                <p className="text-[10px] font-bold uppercase tracking-widest text-[#75B2D6]">
+                <p className="text-[10px] font-bold uppercase tracking-widest text-memento-blue">
                   {resourcePreview.source === 'chat' ? 'Injecter depuis Discussion' : 'Aperçu IA'}
                 </p>
                 <button onClick={() => setResourcePreview(null)} className="text-[#1C1C1C]/40 hover:text-[#1C1C1C]">
@@ -576,7 +584,7 @@ export function ContextualAIChat({
               </div>
               <div className="p-6 border-t border-border flex gap-3 shrink-0">
                 <button onClick={() => setResourcePreview(null)} className="flex-1 py-3.5 text-[10px] font-bold uppercase tracking-widest text-[#1C1C1C]/40 hover:text-[#1C1C1C] transition-all">ANNULER</button>
-                <button onClick={handleApplyResourcePreview} className="flex-1 py-3.5 bg-[#75B2D6] text-white rounded-xl text-[10px] font-bold uppercase tracking-widest shadow-lg shadow-[#75B2D6]/20 transition-all hover:opacity-90">APPLIQUER À LA NOTE</button>
+                <button onClick={handleApplyResourcePreview} className="flex-1 py-3.5 bg-memento-blue text-white rounded-xl text-[10px] font-bold uppercase tracking-widest shadow-lg shadow-memento-blue/20 transition-all hover:opacity-90">APPLIQUER À LA NOTE</button>
               </div>
             </div>
           )}
@@ -594,7 +602,7 @@ export function ContextualAIChat({
                   {messages.length === 0 && (
                     <div className="h-full flex flex-col items-center justify-center text-center space-y-6 py-12">
                       <div className="w-20 h-20 rounded-full bg-white/40 backdrop-blur-sm border border-dashed border-border flex items-center justify-center shadow-sm">
-                        <MessageSquare size={32} className="text-[#75B2D6]/60" />
+                        <MessageSquare size={32} className="text-memento-blue/60" />
                       </div>
                       <p className="text-xs font-serif italic text-[#1C1C1C]/40 leading-relaxed max-w-[200px]">Posez une question à l'Assistant pour commencer.</p>
                     </div>
@@ -623,7 +631,7 @@ export function ContextualAIChat({
                   {isLoading && (
                     <div className="flex flex-col gap-3">
                       <div className="bg-white/60 backdrop-blur-sm border border-border p-5 rounded-2xl shadow-sm w-fit">
-                        <div className="flex gap-1.5"><span className="w-1.5 h-1.5 bg-[#75B2D6] rounded-full animate-pulse" /><span className="w-1.5 h-1.5 bg-[#75B2D6] rounded-full animate-pulse delay-75" /><span className="w-1.5 h-1.5 bg-[#75B2D6] rounded-full animate-pulse delay-150" /></div>
+                        <div className="flex gap-1.5"><span className="w-1.5 h-1.5 bg-memento-blue rounded-full animate-pulse" /><span className="w-1.5 h-1.5 bg-memento-blue rounded-full animate-pulse delay-75" /><span className="w-1.5 h-1.5 bg-memento-blue rounded-full animate-pulse delay-150" /></div>
                       </div>
                     </div>
                   )}
@@ -664,11 +672,11 @@ export function ContextualAIChat({
                               className={cn(
                                 'h-[52px] rounded-xl border transition-all flex flex-col items-center justify-center gap-1.5 shadow-sm',
                                 isActive 
-                                  ? 'bg-[#75B2D6]/10 border-[#75B2D6] text-[#75B2D6]' 
+                                  ? 'bg-memento-blue/10 border-memento-blue text-memento-blue' 
                                   : 'bg-white/60 border-border text-[#1C1C1C]/40 hover:border-[#1C1C1C]/20'
                               )}
                             >
-                              <Icon size={14} className={isActive ? 'text-[#75B2D6]' : 'text-[#1C1C1C]/40'} />
+                              <Icon size={14} className={isActive ? 'text-memento-blue' : 'text-[#1C1C1C]/40'} />
                               <span className="text-[9px] font-bold uppercase tracking-tight">{tone.label}</span>
                             </button>
                           )
@@ -680,7 +688,7 @@ export function ContextualAIChat({
                   <div className="relative">
                     <textarea
                       rows={4}
-                      className="w-full bg-white/60 border border-border rounded-2xl p-5 pr-14 text-sm outline-none focus:border-[#75B2D6] transition-all resize-none leading-relaxed font-light custom-scrollbar shadow-sm text-[#1C1C1C]"
+                      className="w-full bg-white/60 border border-border rounded-2xl p-5 pr-14 text-sm outline-none focus:border-memento-blue transition-all resize-none leading-relaxed font-light custom-scrollbar shadow-sm text-[#1C1C1C]"
                       placeholder="Posez votre question sur cette note..."
                       value={input}
                       onChange={e => setInput(e.target.value)}
@@ -690,12 +698,12 @@ export function ContextualAIChat({
                     <div className="absolute right-4 bottom-4 flex gap-2">
                       <button 
                         onClick={() => setWebSearch(!webSearch)}
-                        className={cn("p-2.5 rounded-xl transition-colors", webSearch ? "text-[#75B2D6] bg-[#75B2D6]/10" : "text-[#1C1C1C]/20 hover:text-[#1C1C1C]")}
+                        className={cn("p-2.5 rounded-xl transition-colors", webSearch ? "text-memento-blue bg-memento-blue/10" : "text-[#1C1C1C]/20 hover:text-[#1C1C1C]")}
                         title="Web Search"
                       >
                         <Globe size={18} />
                       </button>
-                      <button onClick={handleSend} disabled={!input.trim() || isLoading} className="p-2.5 bg-[#75B2D6] text-white rounded-xl transition-all hover:scale-105 active:scale-95 shadow-lg shadow-[#75B2D6]/20 disabled:opacity-30">
+                      <button onClick={handleSend} disabled={!input.trim() || isLoading} className="p-2.5 bg-memento-blue text-white rounded-xl transition-all hover:scale-105 active:scale-95 shadow-lg shadow-memento-blue/20 disabled:opacity-30">
                         <Send size={18} />
                       </button>
                     </div>
@@ -725,7 +733,7 @@ export function ContextualAIChat({
                       initial={{ opacity: 0, y: -10 }}
                       animate={{ opacity: 1, y: 0 }}
                       onClick={onUndoLastAction}
-                      className="w-full py-3.5 bg-[#75B2D6]/20 border border-[#75B2D6]/50 rounded-xl flex items-center justify-center gap-2 text-[11px] font-bold text-[#75B2D6] uppercase tracking-[0.2em] hover:bg-[#75B2D6]/30 transition-all shadow-md"
+                      className="w-full py-3.5 bg-memento-blue/20 border border-memento-blue/50 rounded-xl flex items-center justify-center gap-2 text-[11px] font-bold text-memento-blue uppercase tracking-[0.2em] hover:bg-memento-blue/30 transition-all shadow-md"
                     >
                       <RotateCcw size={12} /> {t('ai.undoLastAction')}
                     </motion.button>
@@ -736,11 +744,11 @@ export function ContextualAIChat({
                       const isActive = action.id === 'translate' && showLangPicker
                       const Icon = action.icon
                       return (
-                        <button key={i} onClick={() => action.id === 'translate' ? setShowLangPicker(v => !v) : handleAction(action)} disabled={!!actionLoading} className={cn("flex flex-col items-center gap-3 p-4 bg-white/40 backdrop-blur-sm border rounded-xl transition-all group shadow-sm", isActive ? "border-[#75B2D6] bg-[#75B2D6]/5" : "border-border hover:border-[#1C1C1C]/20")}>
-                          <div className={cn("p-2 rounded-lg bg-white/60 transition-colors group-hover:bg-[#1C1C1C] group-hover:text-[#FDFDFE] shadow-sm", loading && "animate-pulse", isActive && "bg-[#75B2D6] text-white")}>
+                        <button key={i} onClick={() => action.id === 'translate' ? setShowLangPicker(v => !v) : handleAction(action)} disabled={!!actionLoading} className={cn("flex flex-col items-center gap-3 p-4 bg-white/40 backdrop-blur-sm border rounded-xl transition-all group shadow-sm", isActive ? "border-memento-blue bg-memento-blue/5" : "border-border hover:border-[#1C1C1C]/20")}>
+                          <div className={cn("p-2 rounded-lg bg-white/60 transition-colors group-hover:bg-[#1C1C1C] group-hover:text-[#FDFDFE] shadow-sm", loading && "animate-pulse", isActive && "bg-memento-blue text-white")}>
                             {loading ? <Loader2 size={14} className="animate-spin" /> : <Icon size={14} />}
                           </div>
-                          <span className={cn("text-[10px] font-bold uppercase tracking-widest", isActive ? "text-[#75B2D6]" : "text-[#1C1C1C]/80")}>{t(action.i18nKey)}</span>
+                          <span className={cn("text-[10px] font-bold uppercase tracking-widest", isActive ? "text-memento-blue" : "text-[#1C1C1C]/80")}>{t(action.i18nKey)}</span>
                         </button>
                       )
                     })}
@@ -763,7 +771,7 @@ export function ContextualAIChat({
                                   className={cn(
                                     "py-2 px-1 rounded-lg border text-[10px] font-bold uppercase tracking-tighter transition-all",
                                     translateTarget === lang 
-                                      ? "bg-[#75B2D6] border-[#75B2D6] text-white shadow-md shadow-[#75B2D6]/20" 
+                                      ? "bg-memento-blue border-memento-blue text-white shadow-md shadow-memento-blue/20" 
                                       : "bg-white/60 border-border text-[#1C1C1C]/60 hover:border-[#1C1C1C]/20"
                                   )}
                                 >
@@ -789,7 +797,7 @@ export function ContextualAIChat({
                             <button 
                               onClick={() => handleAction(ACTION_IDS.find(a => a.id === 'translate')!, translateTarget)}
                               disabled={!translateTarget || !!actionLoading}
-                              className="w-full py-3 bg-[#75B2D6] text-white rounded-xl text-[10px] font-bold uppercase tracking-[0.2em] flex items-center justify-center gap-2 hover:opacity-90 disabled:opacity-50 shadow-lg shadow-[#75B2D6]/20"
+                              className="w-full py-3 bg-memento-blue text-white rounded-xl text-[10px] font-bold uppercase tracking-[0.2em] flex items-center justify-center gap-2 hover:opacity-90 disabled:opacity-50 shadow-lg shadow-memento-blue/20"
                             >
                               <Languages size={14} /> {t('ai.translateNow')}
                             </button>
@@ -827,13 +835,13 @@ export function ContextualAIChat({
                     <div className="h-px flex-1 bg-border/40" />
                   </div>
 
-                  <div className="group relative p-6 rounded-2xl bg-white/40 backdrop-blur-sm border border-border hover:border-[#75B2D6]/30 transition-all duration-500 overflow-hidden shadow-sm">
+                  <div className="group relative p-6 rounded-2xl bg-white/40 backdrop-blur-sm border border-border hover:border-memento-blue/30 transition-all duration-500 overflow-hidden shadow-sm">
                     <div className="absolute top-0 right-0 p-4 opacity-5 group-hover:opacity-10 transition-opacity">
-                      <Layout size={80} className="text-[#75B2D6]" />
+                      <Layout size={80} className="text-memento-blue" />
                     </div>
                     <div className="relative space-y-5">
                       <div className="flex items-center gap-3">
-                        <div className="p-2 bg-white/60 rounded-lg text-[#75B2D6]"><Layout size={18} /></div>
+                        <div className="p-2 bg-white/60 rounded-lg text-memento-blue"><Layout size={18} /></div>
                         <div className="space-y-0.5">
                           <h5 className="text-sm font-bold text-[#1C1C1C] leading-none">{t('ai.generate.slides')}</h5>
                           <p className="text-[9px] text-[#1C1C1C]/40 uppercase tracking-tight">{t('ai.generate.sectionLabel')}</p>
@@ -850,14 +858,14 @@ export function ContextualAIChat({
                         </div>
                         <div className="space-y-1.5">
                           <span className="text-[8px] uppercase tracking-[0.2em] font-bold text-[#1C1C1C]/40 px-1">{t('ai.generate.style')}</span>
-                          <select value={slideStyle} onChange={e => setSlideStyle(e.target.value)} className="w-full bg-white/60 border border-border rounded-lg px-2 py-2 text-[10px] outline-none focus:ring-1 ring-[#75B2D6]/10 transition-all cursor-pointer text-[#1C1C1C]">
+                          <select value={slideStyle} onChange={e => setSlideStyle(e.target.value)} className="w-full bg-white/60 border border-border rounded-lg px-2 py-2 text-[10px] outline-none focus:ring-1 ring-memento-blue/10 transition-all cursor-pointer text-[#1C1C1C]">
                             <option value="professional">{t('ai.generate.styleProfessional')}</option>
                             <option value="creative">Creative</option>
                             <option value="brutalist">Brutalist</option>
                           </select>
                         </div>
                       </div>
-                      <button onClick={() => handleGenerate('slides')} disabled={!!generateLoading} className="w-full py-3.5 bg-[#75B2D6] text-white rounded-xl text-[10px] font-bold flex items-center justify-center gap-2 hover:opacity-90 transition-all shadow-lg shadow-[#75B2D6]/20 uppercase tracking-[0.2em] disabled:opacity-50">
+                      <button onClick={() => handleGenerate('slides')} disabled={!!generateLoading} className="w-full py-3.5 bg-memento-blue text-white rounded-xl text-[10px] font-bold flex items-center justify-center gap-2 hover:opacity-90 transition-all shadow-lg shadow-memento-blue/20 uppercase tracking-[0.2em] disabled:opacity-50">
                         {generateLoading === 'slides' ? <Loader2 size={14} className="animate-spin" /> : <><Presentation size={14} className="opacity-80" /> {t('ai.generating')}</>}
                       </button>
 
@@ -865,10 +873,10 @@ export function ContextualAIChat({
                           <motion.div
                             initial={{ opacity: 0, y: 10 }}
                             animate={{ opacity: 1, y: 0 }}
-                            className="mt-4 p-4 bg-[#75B2D6]/10 border border-[#75B2D6]/20 rounded-xl space-y-3"
+                            className="mt-4 p-4 bg-memento-blue/10 border border-memento-blue/20 rounded-xl space-y-3"
                           >
                             <div className="flex items-center justify-between">
-                              <span className="text-[9px] font-bold text-[#75B2D6] uppercase tracking-widest flex items-center gap-1.5">
+                              <span className="text-[9px] font-bold text-memento-blue uppercase tracking-widest flex items-center gap-1.5">
                               <Check size={12} /> Présentation prête
                             </span>
                             <a
@@ -1034,7 +1042,7 @@ export function ContextualAIChat({
                       ))}
                     </div>
                   </div>
-                  <button onClick={handleResourcePreview} disabled={resourceEnriching || resourceScraping || !resourceText.trim()} className="w-full py-4 bg-[#75B2D6] text-white rounded-xl text-[11px] font-bold uppercase tracking-[0.2em] flex items-center justify-center gap-3 hover:opacity-90 transition-opacity shadow-lg shadow-[#75B2D6]/20 disabled:opacity-50">
+                  <button onClick={handleResourcePreview} disabled={resourceEnriching || resourceScraping || !resourceText.trim()} className="w-full py-4 bg-memento-blue text-white rounded-xl text-[11px] font-bold uppercase tracking-[0.2em] flex items-center justify-center gap-3 hover:opacity-90 transition-opacity shadow-lg shadow-memento-blue/20 disabled:opacity-50">
                     {resourceEnriching || resourceScraping ? <Loader2 size={18} className="animate-spin" /> : <Sparkles size={18} />}
                     {t('ai.resource.generatePreview')}
                   </button>