diff --git a/docker-compose.yaml b/docker-compose.yaml
index 637c876..4f36992 100644
--- a/docker-compose.yaml
+++ b/docker-compose.yaml
@@ -18,8 +18,14 @@ services:
     container_name: frontend
     ports:
       - "8071:5173"
+    # Montar solo fuentes de la app (no el Dockerfile ni ficheros de despliegue en /app)
     volumes:
-      - ./frontend:/app
+      - ./frontend/src:/app/src
+      - ./frontend/public:/app/public
+      - ./frontend/index.html:/app/index.html
+      - ./frontend/vite.config.js:/app/vite.config.js
+      - ./frontend/package.json:/app/package.json
+      - ./frontend/package-lock.json:/app/package-lock.json
       - /app/node_modules
     environment:
       - VITE_API_URL=/api
diff --git a/frontend/src/components/layout/Header.jsx b/frontend/src/components/layout/Header.jsx
index 2011ca7..6efe21e 100644
--- a/frontend/src/components/layout/Header.jsx
+++ b/frontend/src/components/layout/Header.jsx
@@ -1,72 +1,152 @@
 import { useState } from 'react';
 import { Link, useNavigate, useLocation } from 'react-router-dom';
-import { useAuth } from '../../context/AuthContext'; 
-import { FiLogIn, FiLogOut } from 'react-icons/fi';
+import { useAuth } from '../../context/AuthContext';
+import { FiLogIn, FiLogOut, FiEdit3, FiClock } from 'react-icons/fi';
+
+function NavTab({ to, isActive, icon: Icon, children }) {
+  return (
+    <Link
+      to={to}
+      aria-current={isActive ? 'page' : undefined}
+      className={[
+        'relative flex items-center gap-2 rounded-lg px-4 py-2.5 text-sm font-semibold transition-all duration-200',
+        'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-blue-500/40 focus-visible:ring-offset-2',
+        isActive
+          ? 'bg-white text-slate-800 shadow-sm ring-1 ring-slate-200/80'
+          : 'text-slate-500 hover:bg-white/50 hover:text-slate-700',
+      ].join(' ')}
+    >
+      <Icon
+        className={`h-4 w-4 shrink-0 ${isActive ? 'text-slate-600' : 'text-slate-400'}`}
+        strokeWidth={2}
+        aria-hidden
+      />
+      <span>{children}</span>
+      {isActive && (
+        <span
+          className="absolute inset-x-3 -bottom-px h-[3px] rounded-full bg-blue-600"
+          aria-hidden
+        />
+      )}
+    </Link>
+  );
+}
+
+function AccederButton({ isActive }) {
+  return (
+    <Link
+      to="/login"
+      aria-current={isActive ? 'page' : undefined}
+      className={[
+        'group relative flex items-center gap-2.5 rounded-lg px-5 py-2.5 text-sm font-semibold text-white transition-all duration-200',
+        'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-blue-500 focus-visible:ring-offset-2',
+        'active:scale-[0.98]',
+        isActive
+          ? 'bg-blue-700 shadow-md shadow-blue-700/35 ring-2 ring-blue-400/50 ring-offset-1 ring-offset-white'
+          : [
+              'bg-blue-600 shadow-md shadow-blue-600/30',
+              'hover:bg-blue-700 hover:shadow-lg hover:shadow-blue-600/35',
+            ].join(' '),
+      ].join(' ')}
+    >
+      <span
+        className="flex h-7 w-7 items-center justify-center rounded-md bg-white/15 text-white transition-colors duration-200 group-hover:bg-white/25"
+        aria-hidden
+      >
+        <FiLogIn className="h-4 w-4" strokeWidth={2.5} />
+      </span>
+      <span>Acceder</span>
+    </Link>
+  );
+}
 
 export default function Header() {
   const [isDropdownOpen, setIsDropdownOpen] = useState(false);
   const navigate = useNavigate();
   const location = useLocation();
-  const { user, logout, isAuthenticated } = useAuth(); 
+  const { user, logout, isAuthenticated } = useAuth();
 
-  const userInitial = user?.username ? user.username[0].toUpperCase() : "U";
+  const userInitial = user?.username ? user.username[0].toUpperCase() : 'U';
 
   const handleLogout = () => {
-    logout(); 
+    logout();
     setIsDropdownOpen(false);
-    navigate('/login'); 
+    navigate('/login');
   };
 
-  const isActive = (path) => {
-    return location.pathname === path || (path === '/editor' && location.pathname === '/');
-  };
+  const isEditorActive =
+    location.pathname === '/editor' || location.pathname === '/';
+  const isHistoryActive = location.pathname.startsWith('/history');
+  const isLoginActive = location.pathname === '/login';
 
   return (
-    <header className="bg-white shadow-sm border-b border-slate-200 sticky top-0 z-50 h-16 shrink-0 w-full">
-      <div className="max-w-7xl mx-auto w-full px-4 sm:px-6 lg:px-8 h-full flex items-center justify-between">
-        
-        <Link to="/" className="flex items-center gap-3 hover:opacity-80 transition-opacity whitespace-nowrap">
-          <img src="/favicon.svg" alt="Deck of Cards Logo" className="w-10 h-10 shadow-sm rounded-xl object-contain" />
-          <span className="text-2xl font-black bg-clip-text text-transparent bg-gradient-to-r from-blue-600 to-indigo-600 hidden sm:block">
+    <header className="sticky top-0 z-50 h-16 w-full shrink-0 border-b border-slate-200 bg-white shadow-sm">
+      <div className="mx-auto flex h-full max-w-7xl items-center justify-between px-4 sm:px-6 lg:px-8">
+        <Link
+          to="/"
+          className="flex items-center gap-3 whitespace-nowrap transition-opacity hover:opacity-80"
+        >
+          <img
+            src="/favicon.svg"
+            alt="Deck of Cards Logo"
+            className="h-10 w-10 rounded-xl object-contain shadow-sm"
+          />
+          <span className="hidden bg-gradient-to-r from-blue-600 to-indigo-600 bg-clip-text text-2xl font-black text-transparent sm:block">
             Deck of Cards
           </span>
         </Link>
 
         <div className="flex items-center gap-4 whitespace-nowrap">
-          <div className="flex items-center gap-1 mr-2">
-            <Link to="/editor" className={`text-sm font-bold px-4 py-2 rounded-lg transition-all ${isActive('/editor') ? 'text-blue-600' : 'text-slate-600 hover:text-blue-500'}`}>
+          {/* Misma navegación con o sin sesión: evita estilos distintos al loguearse */}
+          <nav
+            className="flex items-center gap-0.5 rounded-xl bg-slate-100/90 p-1"
+            aria-label="Secciones principales"
+          >
+            <NavTab to="/editor" isActive={isEditorActive} icon={FiEdit3}>
               Editor
-            </Link>
+            </NavTab>
             {isAuthenticated && (
-              <Link to="/history" className={`text-sm font-bold px-4 py-2 rounded-lg transition-all ${isActive('/history') ? 'text-blue-600' : 'text-slate-600 hover:text-blue-500'}`}>
+              <NavTab to="/history" isActive={isHistoryActive} icon={FiClock}>
                 Historial
-              </Link>
+              </NavTab>
             )}
-          </div>
+          </nav>
 
           {isAuthenticated ? (
             <div className="relative border-l border-slate-200 pl-4">
-              <button 
+              <button
+                type="button"
                 onClick={() => setIsDropdownOpen(!isDropdownOpen)}
-                className="w-10 h-10 rounded-full bg-blue-100 text-blue-700 font-bold flex items-center justify-center border-2 border-blue-200 hover:bg-blue-200 transition-colors"
+                aria-expanded={isDropdownOpen}
+                aria-haspopup="menu"
+                aria-label="Menú de usuario"
+                className="flex h-10 w-10 items-center justify-center rounded-full border-2 border-blue-200 bg-blue-100 text-sm font-bold text-blue-700 transition-colors hover:bg-blue-200 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-blue-500 focus-visible:ring-offset-2"
               >
                 {userInitial}
               </button>
 
               {isDropdownOpen && (
                 <>
-                  <div className="fixed inset-0 z-40" onClick={() => setIsDropdownOpen(false)}></div>
-                  <div className="absolute right-0 mt-2 w-48 bg-white rounded-xl shadow-lg border border-slate-100 py-2 z-50">
-                    <div className="px-4 py-2 border-b border-slate-50">
-                      <p className="text-xs font-bold text-slate-400 uppercase tracking-wider">Usuario</p>
-                      <p className="text-sm font-bold text-slate-700 truncate">{user?.username}</p>
+                  <div
+                    className="fixed inset-0 z-40"
+                    onClick={() => setIsDropdownOpen(false)}
+                    aria-hidden
+                  />
+                  <div className="absolute right-0 z-50 mt-2 w-48 rounded-xl border border-slate-100 bg-white py-2 shadow-lg">
+                    <div className="border-b border-slate-50 px-4 py-2">
+                      <p className="text-xs font-bold uppercase tracking-wider text-slate-400">
+                        Usuario
+                      </p>
+                      <p className="truncate text-sm font-bold text-slate-700">
+                        {user?.username}
+                      </p>
                     </div>
-                    
-                    <button 
-                      onClick={handleLogout} 
-                      className="w-full flex items-center gap-2 px-4 py-2 text-sm font-bold text-red-600 hover:bg-red-50 transition-colors"
+                    <button
+                      type="button"
+                      onClick={handleLogout}
+                      className="flex w-full items-center gap-2 px-4 py-2 text-sm font-bold text-red-600 transition-colors hover:bg-red-50"
                     >
-                      <FiLogOut className="w-5 h-5" strokeWidth={2.5} />
+                      <FiLogOut className="h-5 w-5" strokeWidth={2.5} />
                       Cerrar Sesión
                     </button>
                   </div>
@@ -74,19 +154,12 @@ export default function Header() {
               )}
             </div>
           ) : (
-            <div className="flex items-center border-l border-slate-200 pl-4">
-              
-              <Link 
-                to="/login" 
-                className="flex items-center gap-2 text-sm font-bold bg-blue-600 text-white px-5 py-2.5 rounded-xl shadow-sm hover:bg-blue-700 transition-all active:scale-95"
-              >
-                <FiLogIn className="w-5 h-5" strokeWidth={2.5} />
-                Acceder
-              </Link>
+            <div className="border-l border-slate-200 pl-4">
+              <AccederButton isActive={isLoginActive} />
             </div>
           )}
         </div>
       </div>
     </header>
   );
-}
\ No newline at end of file
+}
diff --git a/frontend/src/index.css b/frontend/src/index.css
index e63f41c..86ca1af 100644
--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@@ -1,5 +1,8 @@
 @import "tailwindcss";
 
+/* Solo escanear código fuente; evita que Tailwind/Vite procesen Dockerfile u otros archivos en /app */
+@source "./src/**/*.{js,jsx}";
+
 body {
   overflow-y: scroll;
 }
\ No newline at end of file
diff --git a/frontend/vite.config.js b/frontend/vite.config.js
index b14feea..4ee34f7 100644
--- a/frontend/vite.config.js
+++ b/frontend/vite.config.js
@@ -8,9 +8,21 @@ export default defineConfig({
     react(),
     tailwindcss(),
   ],
+  optimizeDeps: {
+    entries: ['index.html', 'src/**/*.{js,jsx}'],
+  },
   server: {
     host: '0.0.0.0',
     allowedHosts: true,
+    watch: {
+      ignored: [
+        '**/Dockerfile',
+        '**/.dockerignore',
+        '**/docker-compose*.yml',
+        '**/docker-compose*.yaml',
+        '**/README.md',
+      ],
+    },
     proxy: {
       '/api': {
         target: process.env.BACKEND_URL || 'http://backend:8000',