diff --git a/marketplace/src/layouts/Shell.tsx b/marketplace/src/layouts/Shell.tsx
index 3b9edfd..0fc4353 100644
--- a/marketplace/src/layouts/Shell.tsx
+++ b/marketplace/src/layouts/Shell.tsx
@@ -4,6 +4,9 @@ import { useAuth } from '../context/AuthContext'
 export function Shell({ children }: { children: React.ReactNode }) {
   const { user, logout } = useAuth()
 
+  const isOwner = user?.role === 'owner' || user?.role === 'seller'
+  const isAdmin = user?.role === 'admin'
+
   return (
     <div className="min-h-screen bg-gray-100">
       <header className="flex items-center justify-between bg-medicalBlue px-6 py-4 text-white shadow-md">
@@ -11,20 +14,37 @@ export function Shell({ children }: { children: React.ReactNode }) {
           <div className="h-10 w-10 rounded-full bg-white/10 text-center text-xl font-bold leading-10">MP</div>
           <div>
             <p className="text-lg font-semibold">Marketplace Farmacêutico B2B</p>
-            <p className="text-sm text-gray-100">Dashboard de Compras</p>
+            <p className="text-sm text-gray-100">
+              {isAdmin ? 'Painel Administrativo' : isOwner ? 'Painel do Dono' : 'Dashboard'}
+            </p>
           </div>
         </div>
         <nav className="flex items-center gap-4 text-sm font-medium">
-          <Link to="/dashboard" className="hover:underline">
-            Compras
-          </Link>
+          {isAdmin && (
+            <Link to="/dashboard" className="hover:underline">
+              Admin
+            </Link>
+          )}
+          {isOwner && (
+            <>
+              <Link to="/seller" className="hover:underline">
+                Dashboard
+              </Link>
+              <Link to="/orders" className="hover:underline">
+                Meus Pedidos
+              </Link>
+              <Link to="/inventory" className="hover:underline">
+                Meus Produtos
+              </Link>
+            </>
+          )}
           <Link to="/cart" className="hover:underline">
             Carrinho
           </Link>
           <Link to="/checkout" className="hover:underline">
             Checkout
           </Link>
-          <Link to="/profile" className="hover:underline">
+          <Link to="/company" className="hover:underline">
             Perfil da Empresa
           </Link>
           {user && (
diff --git a/marketplace/src/pages/Checkout.tsx b/marketplace/src/pages/Checkout.tsx
index e1ff8dc..6ef891a 100644
--- a/marketplace/src/pages/Checkout.tsx
+++ b/marketplace/src/pages/Checkout.tsx
@@ -6,6 +6,14 @@ import { useAuth } from '../context/AuthContext'
 
 const MP_PUBLIC_KEY = import.meta.env.VITE_MP_PUBLIC_KEY || 'TEST-PUBLIC-KEY'
 
+// Helper function to safely format currency values
+const formatCurrency = (value: number | undefined | null): string => {
+  if (value === undefined || value === null || isNaN(value)) {
+    return '0,00'
+  }
+  return value.toFixed(2).replace('.', ',')
+}
+
 export function CheckoutPage() {
   const { user } = useAuth()
   const summary = useCartStore(selectCartSummary)
@@ -36,7 +44,7 @@ export function CheckoutPage() {
             <div key={vendorId} className="rounded border border-gray-200 bg-gray-50 p-3">
               <div className="flex items-center justify-between">
                 <p className="font-semibold text-gray-800">{group.vendorName}</p>
-                <p className="text-sm font-bold text-medicalBlue">R$ {group.total.toFixed(2)}</p>
+                <p className="text-sm font-bold text-medicalBlue">R$ {formatCurrency(group.total)}</p>
               </div>
               <p className="text-xs text-gray-600">Itens enviados no split de pagamento.</p>
             </div>
@@ -45,7 +53,7 @@ export function CheckoutPage() {
         <div className="space-y-3 rounded-lg bg-white p-4 shadow-sm">
           <div>
             <p className="text-sm font-semibold text-gray-700">Resumo</p>
-            <p className="text-2xl font-bold text-medicalBlue">R$ {summary.totalValue.toFixed(2)}</p>
+            <p className="text-2xl font-bold text-medicalBlue">R$ {formatCurrency(summary.totalValue)}</p>
           </div>
           <div className="rounded bg-gray-100 p-3 text-sm">
             <p className="font-semibold text-gray-700">Status</p>