diff --git a/apps/desktop/src/api/builtin.l10n.ts b/apps/desktop/src/api/builtin.l10n.ts
index faa2fb90..f2b42618 100644
--- a/apps/desktop/src/api/builtin.l10n.ts
+++ b/apps/desktop/src/api/builtin.l10n.ts
@@ -265,6 +265,10 @@ export function registerBuiltinTranslations() {
         'ai.disclaimer': 'Trixty AI can make mistakes. Check important info.',
         'ai.chat_log_label': 'AI chat transcript',
 
+        'activitybar.label': 'Primary sidebar navigation',
+        'tabbar.label': 'Open editor tabs',
+        'tab.close_aria': 'Close {file}',
+
         'terminal.error_connect': 'Error connecting to terminal: ',
         'editor.empty_desc': 'Select a file from the explorer to begin',
         'editor.view_not_found': 'View not found',
@@ -648,6 +652,10 @@ export function registerBuiltinTranslations() {
         'ai.disclaimer': 'Trixty AI puede cometer errores. Verifica info importante.',
         'ai.chat_log_label': 'Transcripción del chat de IA',
 
+        'activitybar.label': 'Navegación principal del panel lateral',
+        'tabbar.label': 'Pestañas de editores abiertos',
+        'tab.close_aria': 'Cerrar {file}',
+
         'terminal.error_connect': 'Error al conectar con la terminal: ',
         'editor.empty_desc': 'Selecciona un archivo del explorador para comenzar',
         'editor.view_not_found': 'Vista no encontrada',
diff --git a/apps/desktop/src/components/ActivityBar.tsx b/apps/desktop/src/components/ActivityBar.tsx
index 52c4cf92..85145202 100644
--- a/apps/desktop/src/components/ActivityBar.tsx
+++ b/apps/desktop/src/components/ActivityBar.tsx
@@ -43,7 +43,12 @@ const ActivityBar: React.FC = () => {
   };
 
   return (
-    <div className="w-[48px] bg-[#0a0a0a] border-r border-[#1a1a1a] flex flex-col items-center py-2 gap-1 shrink-0">
+    <div
+      role="tablist"
+      aria-orientation="vertical"
+      aria-label={t('activitybar.label')}
+      className="w-[48px] bg-[#0a0a0a] border-r border-[#1a1a1a] flex flex-col items-center py-2 gap-1 shrink-0"
+    >
 
 
       {plugins.map((item) => {
@@ -51,16 +56,19 @@ const ActivityBar: React.FC = () => {
         return (
           <button
             key={item.id}
+            role="tab"
+            aria-selected={isActive}
+            aria-label={t(item.title)}
             onClick={() => handleTabClick(item.id)}
-            className={`w-[40px] h-[40px] flex items-center justify-center rounded-lg transition-all relative group ${isActive ? "text-white bg-white/10" : "text-[#555] hover:text-white/80 hover:bg-white/5"
+            className={`w-[40px] h-[40px] flex items-center justify-center rounded-lg transition-all relative group focus:outline-none focus-visible:ring-2 focus-visible:ring-white/40 ${isActive ? "text-white bg-white/10" : "text-[#555] hover:text-white/80 hover:bg-white/5"
               }`}
             title={t(item.title)}
           >
             {item.icon}
             {isActive && (
-              <div className="absolute left-0 top-[8px] bottom-[8px] w-[2px] bg-white rounded-r-full" />
+              <div aria-hidden="true" className="absolute left-0 top-[8px] bottom-[8px] w-[2px] bg-white rounded-r-full" />
             )}
-            <div className="absolute left-full ml-3 px-2.5 py-1.5 bg-[#1a1a1a] text-white text-[11px] rounded-md border border-[#2a2a2a] opacity-0 group-hover:opacity-100 pointer-events-none whitespace-nowrap z-50 transition-opacity shadow-xl">
+            <div aria-hidden="true" className="absolute left-full ml-3 px-2.5 py-1.5 bg-[#1a1a1a] text-white text-[11px] rounded-md border border-[#2a2a2a] opacity-0 group-hover:opacity-100 pointer-events-none whitespace-nowrap z-50 transition-opacity shadow-xl">
               {t(item.title)}
             </div>
           </button>
@@ -68,22 +76,30 @@ const ActivityBar: React.FC = () => {
       })}
       <div className="mt-auto flex flex-col gap-1 items-center">
         <button
+          role="tab"
+          aria-selected={false}
+          aria-label={t('extensions.title')}
           onClick={() => handleTabClick("extensions")}
-          className="w-[40px] h-[40px] flex mb-1 items-center justify-center rounded-lg text-[#555] hover:text-white/80 hover:bg-white/5 transition-all group relative"
+          className="w-[40px] h-[40px] flex mb-1 items-center justify-center rounded-lg text-[#555] hover:text-white/80 hover:bg-white/5 transition-all group relative focus:outline-none focus-visible:ring-2 focus-visible:ring-white/40"
+          title={t('extensions.title')}
         >
           <Package size={18} strokeWidth={1.5} />
-          <div className="absolute left-full ml-3 px-2.5 py-1.5 bg-[#1a1a1a] text-white text-[11px] rounded-md border border-[#2a2a2a] opacity-0 group-hover:opacity-100 pointer-events-none whitespace-nowrap z-50 transition-opacity shadow-xl">
+          <div aria-hidden="true" className="absolute left-full ml-3 px-2.5 py-1.5 bg-[#1a1a1a] text-white text-[11px] rounded-md border border-[#2a2a2a] opacity-0 group-hover:opacity-100 pointer-events-none whitespace-nowrap z-50 transition-opacity shadow-xl">
             {t('extensions.title')}
           </div>
         </button>
 
         <button
+          role="tab"
+          aria-selected={activeSidebarTab === "settings"}
+          aria-label={t('settings.title')}
           onClick={() => handleTabClick("settings")}
-          className={`w-[40px] h-[40px] flex items-center justify-center rounded-lg transition-all group relative ${activeSidebarTab === "settings" ? "text-white bg-white/10" : "text-[#555] hover:text-white/80 hover:bg-white/5"
+          className={`w-[40px] h-[40px] flex items-center justify-center rounded-lg transition-all group relative focus:outline-none focus-visible:ring-2 focus-visible:ring-white/40 ${activeSidebarTab === "settings" ? "text-white bg-white/10" : "text-[#555] hover:text-white/80 hover:bg-white/5"
             }`}
+          title={t('settings.title')}
         >
           <Settings size={18} strokeWidth={1.5} />
-          <div className="absolute left-full ml-3 px-2.5 py-1.5 bg-[#1a1a1a] text-white text-[11px] rounded-md border border-[#2a2a2a] opacity-0 group-hover:opacity-100 pointer-events-none whitespace-nowrap z-50 transition-opacity shadow-xl">
+          <div aria-hidden="true" className="absolute left-full ml-3 px-2.5 py-1.5 bg-[#1a1a1a] text-white text-[11px] rounded-md border border-[#2a2a2a] opacity-0 group-hover:opacity-100 pointer-events-none whitespace-nowrap z-50 transition-opacity shadow-xl">
             {t('settings.title')}
           </div>
         </button>
diff --git a/apps/desktop/src/components/BottomPanel.tsx b/apps/desktop/src/components/BottomPanel.tsx
index 5856a6d8..a444f5d9 100644
--- a/apps/desktop/src/components/BottomPanel.tsx
+++ b/apps/desktop/src/components/BottomPanel.tsx
@@ -23,7 +23,8 @@ const BottomPanel: React.FC = () => {
         <div className="flex items-center gap-1 text-[#555]">
           <button
             onClick={() => setBottomPanelOpen(false)}
-            className="hover:text-white p-1 rounded hover:bg-white/5 transition-colors"
+            aria-label={t('panel.bottom.close', { defaultValue: 'Close bottom panel' })}
+            className="hover:text-white p-1 rounded hover:bg-white/5 transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-white/40"
           >
             <X size={16} strokeWidth={1.5} />
           </button>
diff --git a/apps/desktop/src/components/TabBar.tsx b/apps/desktop/src/components/TabBar.tsx
index 0506ffc4..7530f878 100644
--- a/apps/desktop/src/components/TabBar.tsx
+++ b/apps/desktop/src/components/TabBar.tsx
@@ -72,36 +72,51 @@ const TabBar: React.FC = () => {
   if (openFiles.length === 0) return null;
 
   return (
-    <div className="flex bg-[#0f0f0f] h-[36px] overflow-x-auto scrollbar-none border-b border-[#1a1a1a] shrink-0">
+    <div
+      role="tablist"
+      aria-label={t('tabbar.label')}
+      className="flex bg-[#0f0f0f] h-[36px] overflow-x-auto scrollbar-none border-b border-[#1a1a1a] shrink-0"
+    >
       {openFiles.map((file) => {
         const isActive = currentFile?.path === file.path;
         return (
           <div
             key={file.path}
+            role="tab"
+            aria-selected={isActive}
+            aria-label={file.isModified ? `${file.name} (${t('tab.modified', { defaultValue: 'unsaved' })})` : file.name}
+            tabIndex={0}
             onClick={() => setCurrentFile(file)}
+            onKeyDown={(e) => {
+              if (e.key === "Enter" || e.key === " ") {
+                e.preventDefault();
+                setCurrentFile(file);
+              }
+            }}
             onContextMenu={(e) => handleContextMenu(e, file.path)}
-            className={`relative flex items-center gap-2 px-3 min-w-[100px] max-w-[180px] h-full cursor-pointer transition-all border-r border-[#1a1a1a] group ${
+            className={`relative flex items-center gap-2 px-3 min-w-[100px] max-w-[180px] h-full cursor-pointer transition-all border-r border-[#1a1a1a] group focus:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-white/40 ${
               isActive
-                ? "bg-[#141414] text-white" 
+                ? "bg-[#141414] text-white"
                 : "text-[#666] hover:text-[#999] hover:bg-[#111]"
             }`}
           >
-            {isActive && <div className="absolute top-0 left-0 right-0 h-[1px] bg-white/40" />}
-            
-            <div className="shrink-0">{getFileIcon(file)}</div>
-            
+            {isActive && <div aria-hidden="true" className="absolute top-0 left-0 right-0 h-[1px] bg-white/40" />}
+
+            <div aria-hidden="true" className="shrink-0">{getFileIcon(file)}</div>
+
             <span className="text-[11px] truncate flex-1">
               {file.name}
             </span>
 
             {file.isModified && (
-              <div className="w-[6px] h-[6px] rounded-full bg-white/40 shrink-0" />
+              <div aria-hidden="true" className="w-[6px] h-[6px] rounded-full bg-white/40 shrink-0" />
             )}
 
             <button
               onClick={(e) => { e.stopPropagation(); closeFile(file.path); }}
-              className={`p-0.5 rounded hover:bg-white/10 transition-opacity shrink-0 ${
-                isActive ? "opacity-60 hover:opacity-100" : "opacity-0 group-hover:opacity-60 hover:!opacity-100"
+              aria-label={t('tab.close_aria', { file: file.name })}
+              className={`p-0.5 rounded hover:bg-white/10 transition-opacity shrink-0 focus:outline-none focus-visible:ring-2 focus-visible:ring-white/40 ${
+                isActive ? "opacity-60 hover:opacity-100" : "opacity-0 group-hover:opacity-60 hover:!opacity-100 focus-visible:opacity-100"
               }`}
             >
               <X size={12} />
diff --git a/apps/desktop/src/components/TitleBar.tsx b/apps/desktop/src/components/TitleBar.tsx
index 1683604c..20e89680 100644
--- a/apps/desktop/src/components/TitleBar.tsx
+++ b/apps/desktop/src/components/TitleBar.tsx
@@ -53,7 +53,9 @@ const TitleBar: React.FC = () => {
         {/* Right Panel Toggle */}
         <button
           onClick={() => setRightPanelOpen(!isRightPanelOpen)}
-          className={`h-full w-[46px] flex items-center justify-center transition-colors ${
+          aria-label={t('panel.right.toggle')}
+          aria-pressed={isRightPanelOpen}
+          className={`h-full w-[46px] flex items-center justify-center transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-white/40 ${
             isRightPanelOpen
               ? "text-white bg-white/10"
               : "text-[#777] hover:bg-white/10 hover:text-white"
@@ -63,10 +65,11 @@ const TitleBar: React.FC = () => {
           <PanelRight size={14} strokeWidth={1.5} />
         </button>
 
-        <div className="w-[1px] h-[14px] bg-[#222]" />
+        <div aria-hidden="true" className="w-[1px] h-[14px] bg-[#222]" />
         <button
           onClick={minimize}
-          className="h-full w-[46px] flex items-center justify-center text-[#777] hover:bg-white/10 hover:text-white transition-colors"
+          aria-label={t('window.minimize')}
+          className="h-full w-[46px] flex items-center justify-center text-[#777] hover:bg-white/10 hover:text-white transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-white/40"
           title={t('window.minimize')}
         >
           <Minus size={14} strokeWidth={1.5} />
@@ -74,7 +77,8 @@ const TitleBar: React.FC = () => {
 
         <button
           onClick={toggleMaximize}
-          className="h-full w-[46px] flex items-center justify-center text-[#777] hover:bg-white/10 hover:text-white transition-colors"
+          aria-label={isMaximized ? t('window.restore') : t('window.maximize')}
+          className="h-full w-[46px] flex items-center justify-center text-[#777] hover:bg-white/10 hover:text-white transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-white/40"
           title={isMaximized ? t('window.restore') : t('window.maximize')}
         >
           {isMaximized ? (
@@ -86,7 +90,8 @@ const TitleBar: React.FC = () => {
 
         <button
           onClick={close}
-          className="h-full w-[46px] flex items-center justify-center text-[#777] hover:bg-[#e81123] hover:text-white transition-colors"
+          aria-label={t('window.close')}
+          className="h-full w-[46px] flex items-center justify-center text-[#777] hover:bg-[#e81123] hover:text-white transition-colors focus:outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-white/40"
           title={t('window.close')}
         >
           <X size={14} strokeWidth={1.5} />