diff --git a/components/Layout.tsx b/components/Layout.tsx
index c2d3949..83b6189 100644
--- a/components/Layout.tsx
+++ b/components/Layout.tsx
@@ -1,7 +1,7 @@
 import React, { useState, useEffect } from 'react';
 import { NavLink, useLocation, useNavigate } from 'react-router-dom';
 import { LayoutDashboard, Users, UserCircle, Bell, Search, Menu, X, LogOut, Hexagon, Settings, Building2 } from 'lucide-react';
-import { USERS } from '../constants';
+import { getAttendances, getUsers, getUserById } from '../services/dataService';
 import { User } from '../types';
 
 const SidebarItem = ({ to, icon: Icon, label, collapsed }: { to: string, icon: any, label: string, collapsed: boolean }) => (
@@ -24,16 +24,19 @@ export const Layout: React.FC<{ children: React.ReactNode }> = ({ children }) =>
   const [isMobileMenuOpen, setIsMobileMenuOpen] = useState(false);
   const location = useLocation();
   const navigate = useNavigate();
-  const [currentUser, setCurrentUser] = useState<User>(USERS[1]); // Default to standard user fallback
+  const [currentUser, setCurrentUser] = useState<User | null>(null);
 
   useEffect(() => {
-    const storedUserId = localStorage.getItem('ctms_user_id');
-    if (storedUserId) {
-      const user = USERS.find(u => u.id === storedUserId);
-      if (user) {
-        setCurrentUser(user);
+    const fetchCurrentUser = async () => {
+      const storedUserId = localStorage.getItem('ctms_user_id');
+      if (storedUserId) {
+        const user = await getUserById(storedUserId);
+        if (user) {
+          setCurrentUser(user);
+        }
       }
-    }
+    };
+    fetchCurrentUser();
   }, []);
 
   const handleLogout = () => {
@@ -41,16 +44,9 @@ export const Layout: React.FC<{ children: React.ReactNode }> = ({ children }) =>
     navigate('/login');
   };
 
-  // Simple title mapping based on route
-  const getPageTitle = () => {
-    if (location.pathname === '/') return 'Dashboard';
-    if (location.pathname.includes('/admin/users')) return 'Gestão de Equipe';
-    if (location.pathname.includes('/users/')) return 'Histórico do Usuário';
-    if (location.pathname.includes('/attendances')) return 'Detalhes do Atendimento';
-    if (location.pathname.includes('/super-admin')) return 'Gestão de Organizações';
-    if (location.pathname.includes('/profile')) return 'Meu Perfil';
-    return 'CTMS';
-  };
+  if (!currentUser) {
+    return <div className="flex h-screen items-center justify-center bg-slate-50">Carregando...</div>;
+  }
 
   const isSuperAdmin = currentUser.role === 'super_admin';
 
diff --git a/pages/Dashboard.tsx b/pages/Dashboard.tsx
index 25bd0c2..dc1d5d3 100644
--- a/pages/Dashboard.tsx
+++ b/pages/Dashboard.tsx
@@ -40,10 +40,11 @@ export const Dashboard: React.FC = () => {
     const fetchData = async () => {
       setLoading(true);
       try {
+        const tenantId = localStorage.getItem('ctms_tenant_id') || CURRENT_TENANT_ID;
         // Fetch users and attendances in parallel
         const [fetchedUsers, fetchedData] = await Promise.all([
-          getUsers(CURRENT_TENANT_ID),
-          getAttendances(CURRENT_TENANT_ID, filters)
+          getUsers(tenantId),
+          getAttendances(tenantId, filters)
         ]);
         
         setUsers(fetchedUsers);
diff --git a/pages/Login.tsx b/pages/Login.tsx
index 3884325..88ad427 100644
--- a/pages/Login.tsx
+++ b/pages/Login.tsx
@@ -1,7 +1,7 @@
 import React, { useState } from 'react';
 import { useNavigate } from 'react-router-dom';
 import { Hexagon, Lock, Mail, ArrowRight, Loader2, Info } from 'lucide-react';
-import { USERS } from '../constants';
+import { getUsers } from '../services/dataService';
 
 export const Login: React.FC = () => {
   const navigate = useNavigate();
@@ -10,18 +10,20 @@ export const Login: React.FC = () => {
   const [password, setPassword] = useState('password');
   const [error, setError] = useState('');
 
-  const handleLogin = (e: React.FormEvent) => {
+  const handleLogin = async (e: React.FormEvent) => {
     e.preventDefault();
     setIsLoading(true);
     setError('');
     
-    // Simulate API call and validation
-    setTimeout(() => {
-      const user = USERS.find(u => u.email.toLowerCase() === email.toLowerCase());
+    try {
+      // Fetch all users to find match (simplified auth for demo)
+      const users = await getUsers('all');
+      const user = users.find(u => u.email.toLowerCase() === email.toLowerCase());
 
       if (user) {
         // Mock Login: Save to local storage
         localStorage.setItem('ctms_user_id', user.id);
+        localStorage.setItem('ctms_tenant_id', user.tenant_id);
         
         setIsLoading(false);
         
@@ -33,9 +35,13 @@ export const Login: React.FC = () => {
         }
       } else {
         setIsLoading(false);
-        setError('Usuário não encontrado. Tente lidya@fasto.com ou root@system.com');
+        setError('Usuário não encontrado. Tente os e-mails cadastrados.');
       }
-    }, 1000);
+    } catch (err) {
+      console.error("Login error:", err);
+      setIsLoading(false);
+      setError('Erro ao conectar ao servidor.');
+    }
   };
 
   const fillCredentials = (type: 'admin' | 'super') => {
diff --git a/pages/TeamManagement.tsx b/pages/TeamManagement.tsx
index ff314b7..6908bcf 100644
--- a/pages/TeamManagement.tsx
+++ b/pages/TeamManagement.tsx
@@ -1,13 +1,27 @@
-import React, { useState } from 'react';
+import React, { useState, useEffect } from 'react';
 import { Users, Plus, MoreHorizontal, Mail, Shield, Search, X, Edit, Trash2, Save } from 'lucide-react';
-import { USERS } from '../constants';
+import { getUsers } from '../services/dataService';
+import { CURRENT_TENANT_ID } from '../constants';
 import { User } from '../types';
 
 export const TeamManagement: React.FC = () => {
-  const [users, setUsers] = useState<User[]>(USERS.filter(u => u.role !== 'super_admin')); // Default hide super admin from list
+  const [users, setUsers] = useState<User[]>([]);
+  const [loading, setLoading] = useState(true);
   const [isModalOpen, setIsModalOpen] = useState(false);
   const [searchTerm, setSearchTerm] = useState('');
   
+  useEffect(() => {
+    const fetchUsers = async () => {
+      setLoading(true);
+      const tenantId = localStorage.getItem('ctms_tenant_id') || CURRENT_TENANT_ID;
+      const data = await getUsers(tenantId);
+      // Hide super admin from the list for standard admin view
+      setUsers(data.filter(u => u.role !== 'super_admin'));
+      setLoading(false);
+    };
+    fetchUsers();
+  }, []);
+  
   // State for handling Add/Edit
   const [editingUser, setEditingUser] = useState<User | null>(null);
   const [formData, setFormData] = useState({
@@ -23,6 +37,10 @@ export const TeamManagement: React.FC = () => {
     u.email.toLowerCase().includes(searchTerm.toLowerCase())
   );
 
+  if (loading && users.length === 0) {
+    return <div className="flex h-full items-center justify-center text-slate-400 p-12 text-center">Carregando equipe...</div>;
+  }
+
   const getRoleBadge = (role: string) => {
     switch (role) {
       case 'super_admin': return 'bg-slate-900 text-white border-slate-700';
diff --git a/pages/UserDetail.tsx b/pages/UserDetail.tsx
index b1028e5..e80f628 100644
--- a/pages/UserDetail.tsx
+++ b/pages/UserDetail.tsx
@@ -20,11 +20,12 @@ export const UserDetail: React.FC = () => {
       
       const loadData = async () => {
         try {
+          const tenantId = localStorage.getItem('ctms_tenant_id') || CURRENT_TENANT_ID;
           const u = await getUserById(id);
           setUser(u);
           
           if (u) {
-            const data = await getAttendances(CURRENT_TENANT_ID, { 
+            const data = await getAttendances(tenantId, { 
               userId: id, 
               dateRange: { start: new Date(0), end: new Date() } // All time
             });
diff --git a/pages/UserProfile.tsx b/pages/UserProfile.tsx
index 8fc90a6..387bbc1 100644
--- a/pages/UserProfile.tsx
+++ b/pages/UserProfile.tsx
@@ -1,6 +1,6 @@
 import React, { useState, useEffect } from 'react';
 import { Camera, Save, Mail, User as UserIcon, Building, Shield, Loader2, CheckCircle2 } from 'lucide-react';
-import { USERS } from '../constants';
+import { getUserById } from '../services/dataService';
 import { User } from '../types';
 
 export const UserProfile: React.FC = () => {
@@ -14,11 +14,18 @@ export const UserProfile: React.FC = () => {
   const [bio, setBio] = useState('');
   
   useEffect(() => {
-    // Simulate fetching user data
-    const currentUser = USERS[0];
-    setUser(currentUser);
-    setName(currentUser.name);
-    setBio(currentUser.bio || '');
+    const fetchUser = async () => {
+      const storedId = localStorage.getItem('ctms_user_id');
+      if (storedId) {
+        const fetchedUser = await getUserById(storedId);
+        if (fetchedUser) {
+          setUser(fetchedUser);
+          setName(fetchedUser.name);
+          setBio(fetchedUser.bio || '');
+        }
+      }
+    };
+    fetchUser();
   }, []);
 
   const handleSubmit = (e: React.FormEvent) => {