diff --git a/app.py b/app.py
index 9ec27d3..6a66c0a 100644
--- a/app.py
+++ b/app.py
@@ -1,54 +1,310 @@
-from flask import Flask, render_template, request, redirect, url_for, jsonify, flash
-from models import db, TimeEntry, WorkConfig
-from datetime import datetime, time
+from flask import Flask, render_template, request, redirect, url_for, jsonify, flash, session, g
+from models import db, TimeEntry, WorkConfig, User
+import logging
+from datetime import datetime, time, timedelta
 import os
 from sqlalchemy import func
+from functools import wraps
+
+# Configure logging
+logging.basicConfig(level=logging.DEBUG)
 
 app = Flask(__name__)
 app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///timetrack.db'
 app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
-app.config['SECRET_KEY'] = os.environ.get('SECRET_KEY', 'dev_key_for_timetrack')  # Add secret key for flash messages
+app.config['SECRET_KEY'] = os.environ.get('SECRET_KEY', 'dev_key_for_timetrack')
+app.config['PERMANENT_SESSION_LIFETIME'] = timedelta(days=7)  # Session lasts for 7 days
 
 # Initialize the database with the app
 db.init_app(app)
 
+# Authentication decorator
+def login_required(f):
+    @wraps(f)
+    def decorated_function(*args, **kwargs):
+        if 'user_id' not in session:
+            flash('Please log in to access this page', 'error')
+            return redirect(url_for('login', next=request.url))
+        return f(*args, **kwargs)
+    return decorated_function
+
+# Admin-only decorator
+def admin_required(f):
+    @wraps(f)
+    def decorated_function(*args, **kwargs):
+        if 'user_id' not in session:
+            flash('Please log in to access this page', 'error')
+            return redirect(url_for('login', next=request.url))
+        
+        user = User.query.get(session['user_id'])
+        if not user or not user.is_admin:
+            flash('You need administrator privileges to access this page', 'error')
+            return redirect(url_for('home'))
+        return f(*args, **kwargs)
+    return decorated_function
+
+@app.before_request
+def load_logged_in_user():
+    user_id = session.get('user_id')
+    if user_id is None:
+        g.user = None
+    else:
+        g.user = User.query.get(user_id)
+
 @app.route('/')
 def home():
-    # Get active time entry (if any)
-    active_entry = TimeEntry.query.filter_by(departure_time=None).first()
+    if g.user:
+        # Get active time entry (if any) for the current user
+        active_entry = TimeEntry.query.filter_by(user_id=g.user.id, departure_time=None).first()
 
-    # Get today's date
-    today = datetime.now().date()
+        # Get today's date
+        today = datetime.now().date()
 
-    # Get time entries for today only
-    today_start = datetime.combine(today, time.min)
-    today_end = datetime.combine(today, time.max)
+        # Get time entries for today only for the current user
+        today_start = datetime.combine(today, time.min)
+        today_end = datetime.combine(today, time.max)
 
-    today_entries = TimeEntry.query.filter(
-        TimeEntry.arrival_time >= today_start,
-        TimeEntry.arrival_time <= today_end
-    ).order_by(TimeEntry.arrival_time.desc()).all()
+        today_entries = TimeEntry.query.filter(
+            TimeEntry.user_id == g.user.id,
+            TimeEntry.arrival_time >= today_start,
+            TimeEntry.arrival_time <= today_end
+        ).order_by(TimeEntry.arrival_time.desc()).all()
 
-    return render_template('index.html', title='Home', active_entry=active_entry, history=today_entries)
+        return render_template('index.html', title='Home', active_entry=active_entry, history=today_entries)
+    else:
+        # Show landing page for non-logged in users
+        return render_template('index.html', title='Home')
+
+@app.route('/login', methods=['GET', 'POST'])
+def login():
+    if request.method == 'POST':
+        username = request.form.get('username')
+        password = request.form.get('password')
+        remember = 'remember' in request.form
+        
+        user = User.query.filter_by(username=username).first()
+        
+        if user and user.check_password(password):
+            session.clear()
+            session['user_id'] = user.id
+            if remember:
+                session.permanent = True
+            
+            next_page = request.args.get('next')
+            if not next_page or not next_page.startswith('/'):
+                next_page = url_for('home')
+                
+            flash(f'Welcome back, {user.username}!', 'success')
+            return redirect(next_page)
+        
+        flash('Invalid username or password', 'error')
+    
+    return render_template('login.html', title='Login')
+
+@app.route('/logout')
+def logout():
+    session.clear()
+    flash('You have been logged out', 'info')
+    return redirect(url_for('login'))
+
+@app.route('/register', methods=['GET', 'POST'])
+def register():
+    if request.method == 'POST':
+        username = request.form.get('username')
+        email = request.form.get('email')
+        password = request.form.get('password')
+        confirm_password = request.form.get('confirm_password')
+        
+        # Validate input
+        error = None
+        if not username:
+            error = 'Username is required'
+        elif not email:
+            error = 'Email is required'
+        elif not password:
+            error = 'Password is required'
+        elif password != confirm_password:
+            error = 'Passwords do not match'
+        elif User.query.filter_by(username=username).first():
+            error = 'Username already exists'
+        elif User.query.filter_by(email=email).first():
+            error = 'Email already registered'
+            
+        if error is None:
+            new_user = User(username=username, email=email)
+            new_user.set_password(password)
+            
+            db.session.add(new_user)
+            db.session.commit()
+            
+            flash('Registration successful! You can now log in.', 'success')
+            return redirect(url_for('login'))
+        
+        flash(error, 'error')
+    
+    return render_template('register.html', title='Register')
+
+@app.route('/admin/users')
+@admin_required
+def admin_users():
+    users = User.query.all()
+    return render_template('admin_users.html', title='User Management', users=users)
+
+@app.route('/admin/users/create', methods=['GET', 'POST'])
+@admin_required
+def create_user():
+    if request.method == 'POST':
+        username = request.form.get('username')
+        email = request.form.get('email')
+        password = request.form.get('password')
+        is_admin = 'is_admin' in request.form
+        
+        # Validate input
+        error = None
+        if not username:
+            error = 'Username is required'
+        elif not email:
+            error = 'Email is required'
+        elif not password:
+            error = 'Password is required'
+        elif User.query.filter_by(username=username).first():
+            error = 'Username already exists'
+        elif User.query.filter_by(email=email).first():
+            error = 'Email already registered'
+            
+        if error is None:
+            new_user = User(username=username, email=email, is_admin=is_admin)
+            new_user.set_password(password)
+            
+            db.session.add(new_user)
+            db.session.commit()
+            
+            flash(f'User {username} created successfully!', 'success')
+            return redirect(url_for('admin_users'))
+        
+        flash(error, 'error')
+    
+    return render_template('create_user.html', title='Create User')
+
+@app.route('/admin/users/edit/<int:user_id>', methods=['GET', 'POST'])
+@admin_required
+def edit_user(user_id):
+    user = User.query.get_or_404(user_id)
+    
+    if request.method == 'POST':
+        username = request.form.get('username')
+        email = request.form.get('email')
+        password = request.form.get('password')
+        is_admin = 'is_admin' in request.form
+        
+        # Validate input
+        error = None
+        if not username:
+            error = 'Username is required'
+        elif not email:
+            error = 'Email is required'
+        elif username != user.username and User.query.filter_by(username=username).first():
+            error = 'Username already exists'
+        elif email != user.email and User.query.filter_by(email=email).first():
+            error = 'Email already registered'
+            
+        if error is None:
+            user.username = username
+            user.email = email
+            user.is_admin = is_admin
+            
+            if password:
+                user.set_password(password)
+            
+            db.session.commit()
+            
+            flash(f'User {username} updated successfully!', 'success')
+            return redirect(url_for('admin_users'))
+        
+        flash(error, 'error')
+    
+    return render_template('edit_user.html', title='Edit User', user=user)
+
+@app.route('/admin/users/delete/<int:user_id>', methods=['POST'])
+@admin_required
+def delete_user(user_id):
+    user = User.query.get_or_404(user_id)
+    
+    # Prevent deleting yourself
+    if user.id == session.get('user_id'):
+        flash('You cannot delete your own account', 'error')
+        return redirect(url_for('admin_users'))
+    
+    username = user.username
+    db.session.delete(user)
+    db.session.commit()
+    
+    flash(f'User {username} deleted successfully', 'success')
+    return redirect(url_for('admin_users'))
+
+@app.route('/profile', methods=['GET', 'POST'])
+@login_required
+def profile():
+    user = User.query.get(session['user_id'])
+    
+    if request.method == 'POST':
+        email = request.form.get('email')
+        current_password = request.form.get('current_password')
+        new_password = request.form.get('new_password')
+        confirm_password = request.form.get('confirm_password')
+        
+        # Validate input
+        error = None
+        if not email:
+            error = 'Email is required'
+        elif email != user.email and User.query.filter_by(email=email).first():
+            error = 'Email already registered'
+        
+        # Password change validation
+        if new_password:
+            if not current_password:
+                error = 'Current password is required to set a new password'
+            elif not user.check_password(current_password):
+                error = 'Current password is incorrect'
+            elif new_password != confirm_password:
+                error = 'New passwords do not match'
+        
+        if error is None:
+            user.email = email
+            
+            if new_password:
+                user.set_password(new_password)
+            
+            db.session.commit()
+            flash('Profile updated successfully!', 'success')
+            return redirect(url_for('profile'))
+        
+        flash(error, 'error')
+    
+    return render_template('profile.html', title='My Profile', user=user)
 
 @app.route('/about')
+@login_required
 def about():
     return render_template('about.html', title='About')
 
 @app.route('/contact', methods=['GET', 'POST'])
+@login_required
 def contact():
     # redacted
     return render_template('contact.html', title='Contact')
 
 # We can keep this route as a redirect to home for backward compatibility
 @app.route('/timetrack')
+@login_required
 def timetrack():
     return redirect(url_for('home'))
 
 @app.route('/api/arrive', methods=['POST'])
+@login_required
 def arrive():
-    # Create a new time entry with arrival time
-    new_entry = TimeEntry(arrival_time=datetime.now())
+    # Create a new time entry with arrival time for the current user
+    new_entry = TimeEntry(user_id=session['user_id'], arrival_time=datetime.now())
     db.session.add(new_entry)
     db.session.commit()
 
@@ -58,9 +314,10 @@ def arrive():
     })
 
 @app.route('/api/leave/<int:entry_id>', methods=['POST'])
+@login_required
 def leave(entry_id):
-    # Find the time entry
-    entry = TimeEntry.query.get_or_404(entry_id)
+    # Find the time entry for the current user
+    entry = TimeEntry.query.filter_by(id=entry_id, user_id=session['user_id']).first_or_404()
 
     # Set the departure time
     departure_time = datetime.now()
@@ -93,9 +350,10 @@ def leave(entry_id):
 
 # Add this new route to handle pausing/resuming
 @app.route('/api/toggle-pause/<int:entry_id>', methods=['POST'])
+@login_required
 def toggle_pause(entry_id):
-    # Find the time entry
-    entry = TimeEntry.query.get_or_404(entry_id)
+    # Find the time entry for the current user
+    entry = TimeEntry.query.filter_by(id=entry_id, user_id=session['user_id']).first_or_404()
 
     now = datetime.now()
 
@@ -124,6 +382,7 @@ def toggle_pause(entry_id):
     })
 
 @app.route('/config', methods=['GET', 'POST'])
+@login_required
 def config():
     # Get current configuration or create default if none exists
     config = WorkConfig.query.order_by(WorkConfig.id.desc()).first()
@@ -164,15 +423,17 @@ def create_tables():
         print("WARNING: Database schema is outdated. Please run migrate_db.py to update it.")
 
 @app.route('/api/delete/<int:entry_id>', methods=['DELETE'])
+@login_required
 def delete_entry(entry_id):
-    entry = TimeEntry.query.get_or_404(entry_id)
+    entry = TimeEntry.query.filter_by(id=entry_id, user_id=session['user_id']).first_or_404()
     db.session.delete(entry)
     db.session.commit()
     return jsonify({'success': True, 'message': 'Entry deleted successfully'})
 
 @app.route('/api/update/<int:entry_id>', methods=['PUT'])
+@login_required
 def update_entry(entry_id):
-    entry = TimeEntry.query.get_or_404(entry_id)
+    entry = TimeEntry.query.filter_by(id=entry_id, user_id=session['user_id']).first_or_404()
     data = request.json
 
     if 'arrival_time' in data:
@@ -210,9 +471,10 @@ def update_entry(entry_id):
     })
 
 @app.route('/history')
+@login_required
 def history():
-    # Get all time entries, ordered by most recent first
-    all_entries = TimeEntry.query.order_by(TimeEntry.arrival_time.desc()).all()
+    # Get all time entries for the current user, ordered by most recent first
+    all_entries = TimeEntry.query.filter_by(user_id=session['user_id']).order_by(TimeEntry.arrival_time.desc()).all()
 
     return render_template('history.html', title='Time Entry History', entries=all_entries)
 
@@ -263,12 +525,13 @@ def calculate_work_duration(arrival_time, departure_time, total_break_duration):
     return work_duration, effective_break_duration
 
 @app.route('/api/resume/<int:entry_id>', methods=['POST'])
+@login_required
 def resume_entry(entry_id):
-    # Find the entry to resume
-    entry_to_resume = TimeEntry.query.get_or_404(entry_id)
+    # Find the entry to resume for the current user
+    entry_to_resume = TimeEntry.query.filter_by(id=entry_id, user_id=session['user_id']).first_or_404()
 
     # Check if there's already an active entry
-    active_entry = TimeEntry.query.filter_by(departure_time=None).first()
+    active_entry = TimeEntry.query.filter_by(user_id=session['user_id'], departure_time=None).first()
     if active_entry:
         return jsonify({
             'success': False,
@@ -292,5 +555,21 @@ def resume_entry(entry_id):
         'total_break_duration': entry_to_resume.total_break_duration
     })
 
+@app.errorhandler(404)
+def page_not_found(e):
+    return render_template('404.html'), 404
+
+@app.errorhandler(500)
+def internal_server_error(e):
+    return render_template('500.html'), 500
+
+@app.route('/test')
+def test():
+    return "App is working!"
+
+@app.context_processor
+def inject_current_year():
+    return {'current_year': datetime.now().year}
+
 if __name__ == '__main__':
     app.run(debug=True)
\ No newline at end of file
diff --git a/migrate_db.py b/migrate_db.py
index e78e85e..b409630 100644
--- a/migrate_db.py
+++ b/migrate_db.py
@@ -1,6 +1,9 @@
 from app import app, db
 import sqlite3
 import os
+from models import User, TimeEntry, WorkConfig
+from werkzeug.security import generate_password_hash
+from datetime import datetime
 
 def migrate_database():
     db_path = 'timetrack.db'
@@ -34,6 +37,11 @@ def migrate_database():
     if 'total_break_duration' not in time_entry_columns:
         print("Adding total_break_duration column to time_entry...")
         cursor.execute("ALTER TABLE time_entry ADD COLUMN total_break_duration INTEGER DEFAULT 0")
+        
+    # Add user_id column if it doesn't exist
+    if 'user_id' not in time_entry_columns:
+        print("Adding user_id column to time_entry...")
+        cursor.execute("ALTER TABLE time_entry ADD COLUMN user_id INTEGER")
 
     # Check if the work_config table exists
     cursor.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='work_config'")
@@ -46,7 +54,8 @@ def migrate_database():
             mandatory_break_minutes INTEGER DEFAULT 30,
             break_threshold_hours FLOAT DEFAULT 6.0,
             created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+            updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            user_id INTEGER
         )
         """)
         # Insert default config
@@ -67,12 +76,49 @@ def migrate_database():
         if 'additional_break_threshold_hours' not in work_config_columns:
             print("Adding additional_break_threshold_hours column to work_config...")
             cursor.execute("ALTER TABLE work_config ADD COLUMN additional_break_threshold_hours FLOAT DEFAULT 9.0")
+            
+        # Add user_id column to work_config if it doesn't exist
+        if 'user_id' not in work_config_columns:
+            print("Adding user_id column to work_config...")
+            cursor.execute("ALTER TABLE work_config ADD COLUMN user_id INTEGER")
 
     # Commit changes and close connection
     conn.commit()
     conn.close()
 
-    print("Database migration completed successfully!")
+    with app.app_context():
+        # Create tables if they don't exist
+        db.create_all()
+        
+        # Check if admin user exists
+        admin = User.query.filter_by(username='admin').first()
+        if not admin:
+            # Create admin user
+            admin = User(
+                username='admin',
+                email='admin@timetrack.local',
+                is_admin=True
+            )
+            admin.set_password('admin')  # Default password, should be changed
+            db.session.add(admin)
+            db.session.commit()
+            print("Created admin user with username 'admin' and password 'admin'")
+            print("Please change the admin password after first login!")
+        
+        # Update existing time entries to associate with admin user
+        orphan_entries = TimeEntry.query.filter_by(user_id=None).all()
+        for entry in orphan_entries:
+            entry.user_id = admin.id
+        
+        # Update existing work configs to associate with admin user
+        orphan_configs = WorkConfig.query.filter_by(user_id=None).all()
+        for config in orphan_configs:
+            config.user_id = admin.id
+            
+        db.session.commit()
+        print(f"Associated {len(orphan_entries)} existing time entries with admin user")
+        print(f"Associated {len(orphan_configs)} existing work configs with admin user")
 
 if __name__ == "__main__":
-    migrate_database()
\ No newline at end of file
+    migrate_database()
+    print("Database migration completed")
\ No newline at end of file
diff --git a/models.py b/models.py
index 1e92c1b..aeb3d2c 100644
--- a/models.py
+++ b/models.py
@@ -1,8 +1,29 @@
 from flask_sqlalchemy import SQLAlchemy
+from werkzeug.security import generate_password_hash, check_password_hash
 from datetime import datetime
 
 db = SQLAlchemy()
 
+class User(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    username = db.Column(db.String(64), unique=True, nullable=False)
+    email = db.Column(db.String(120), unique=True, nullable=False)
+    password_hash = db.Column(db.String(128))
+    is_admin = db.Column(db.Boolean, default=False)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+    
+    # Relationship with TimeEntry
+    time_entries = db.relationship('TimeEntry', backref='user', lazy='dynamic')
+    
+    def set_password(self, password):
+        self.password_hash = generate_password_hash(password)
+        
+    def check_password(self, password):
+        return check_password_hash(self.password_hash, password)
+    
+    def __repr__(self):
+        return f'<User {self.username}>'
+
 class TimeEntry(db.Model):
     id = db.Column(db.Integer, primary_key=True)
     arrival_time = db.Column(db.DateTime, nullable=False)
@@ -11,6 +32,7 @@ class TimeEntry(db.Model):
     is_paused = db.Column(db.Boolean, default=False)
     pause_start_time = db.Column(db.DateTime, nullable=True)
     total_break_duration = db.Column(db.Integer, default=0)  # Total break duration in seconds
+    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=True)
 
     def __repr__(self):
         return f'<TimeEntry {self.id}: {self.arrival_time} - {self.departure_time}>'
@@ -24,6 +46,7 @@ class WorkConfig(db.Model):
     additional_break_threshold_hours = db.Column(db.Float, default=9.0)  # Work hours that trigger additional break
     created_at = db.Column(db.DateTime, default=datetime.now)
     updated_at = db.Column(db.DateTime, default=datetime.now, onupdate=datetime.now)
+    user_id = db.Column(db.Integer, db.ForeignKey('user.id'), nullable=True)
 
     def __repr__(self):
         return f'<WorkConfig {self.id}: {self.work_hours_per_day}h/day, {self.mandatory_break_minutes}min break>'
\ No newline at end of file
diff --git a/static/js/script.js b/static/js/script.js
index 1fb14b9..a3c7bae 100644
--- a/static/js/script.js
+++ b/static/js/script.js
@@ -132,6 +132,37 @@ document.addEventListener('DOMContentLoaded', function() {
             });
         });
     }
+
+    // Add dropdown menu functionality
+    const dropdownToggles = document.querySelectorAll('.dropdown-toggle');
+    
+    dropdownToggles.forEach(toggle => {
+        toggle.addEventListener('click', function(e) {
+            e.preventDefault();
+            const parent = this.parentElement;
+            const menu = parent.querySelector('.dropdown-menu');
+            
+            // Close all other open dropdowns
+            document.querySelectorAll('.dropdown-menu').forEach(item => {
+                if (item !== menu && item.classList.contains('show')) {
+                    item.classList.remove('show');
+                }
+            });
+            
+            // Toggle current dropdown
+            menu.classList.toggle('show');
+        });
+    });
+    
+    // Close dropdown when clicking outside
+    document.addEventListener('click', function(e) {
+        if (!e.target.matches('.dropdown-toggle')) {
+            const dropdowns = document.querySelectorAll('.dropdown-menu.show');
+            dropdowns.forEach(dropdown => {
+                dropdown.classList.remove('show');
+            });
+        }
+    });
 });
 
 // Add event listener for resume work buttons
diff --git a/templates/404.html b/templates/404.html
new file mode 100644
index 0000000..0ea8250
--- /dev/null
+++ b/templates/404.html
@@ -0,0 +1,9 @@
+{% extends "layout.html" %}
+
+{% block content %}
+<div class="error-container">
+    <h1>404 - Page Not Found</h1>
+    <p>The page you are looking for does not exist.</p>
+    <a href="{{ url_for('home') }}" class="btn">Return to Home</a>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/500.html b/templates/500.html
new file mode 100644
index 0000000..e69de29
diff --git a/templates/admin_users.html b/templates/admin_users.html
new file mode 100644
index 0000000..ed6cd72
--- /dev/null
+++ b/templates/admin_users.html
@@ -0,0 +1,88 @@
+{% extends "layout.html" %}
+
+{% block content %}
+<div class="admin-container">
+    <h1>User Management</h1>
+    
+    {% with messages = get_flashed_messages(with_categories=true) %}
+        {% if messages %}
+            {% for category, message in messages %}
+                <div class="alert alert-{{ category }}">{{ message }}</div>
+            {% endfor %}
+        {% endif %}
+    {% endwith %}
+    
+    <div class="admin-actions">
+        <a href="{{ url_for('create_user') }}" class="btn btn-success">Create New User</a>
+    </div>
+    
+    <div class="user-list">
+        <table class="table">
+            <thead>
+                <tr>
+                    <th>Username</th>
+                    <th>Email</th>
+                    <th>Role</th>
+                    <th>Created</th>
+                    <th>Actions</th>
+                </tr>
+            </thead>
+            <tbody>
+                {% for user in users %}
+                <tr>
+                    <td>{{ user.username }}</td>
+                    <td>{{ user.email }}</td>
+                    <td>{% if user.is_admin %}Admin{% else %}User{% endif %}</td>
+                    <td>{{ user.created_at.strftime('%Y-%m-%d') }}</td>
+                    <td>
+                        <a href="{{ url_for('edit_user', user_id=user.id) }}" class="btn btn-sm btn-primary">Edit</a>
+                        {% if user.id != g.user.id %}
+                        <button class="btn btn-sm btn-danger" onclick="confirmDelete({{ user.id }}, '{{ user.username }}')">Delete</button>
+                        {% endif %}
+                    </td>
+                </tr>
+                {% endfor %}
+            </tbody>
+        </table>
+    </div>
+    
+    <!-- Delete Confirmation Modal -->
+    <div id="delete-modal" class="modal">
+        <div class="modal-content">
+            <span class="close">&times;</span>
+            <h2>Confirm Deletion</h2>
+            <p>Are you sure you want to delete user <span id="delete-username"></span>?</p>
+            <p>This action cannot be undone.</p>
+            <form id="delete-form" method="POST">
+                <button type="button" id="cancel-delete" class="btn btn-secondary">Cancel</button>
+                <button type="submit" class="btn btn-danger">Delete</button>
+            </form>
+        </div>
+    </div>
+    
+    <script>
+        function confirmDelete(userId, username) {
+            document.getElementById('delete-username').textContent = username;
+            document.getElementById('delete-form').action = "{{ url_for('delete_user', user_id=0) }}".replace('0', userId);
+            document.getElementById('delete-modal').style.display = 'block';
+        }
+        
+        // Close modal when clicking the X
+        document.querySelector('.close').addEventListener('click', function() {
+            document.getElementById('delete-modal').style.display = 'none';
+        });
+        
+        // Close modal when clicking Cancel
+        document.getElementById('cancel-delete').addEventListener('click', function() {
+            document.getElementById('delete-modal').style.display = 'none';
+        });
+        
+        // Close modal when clicking outside
+        window.addEventListener('click', function(event) {
+            if (event.target == document.getElementById('delete-modal')) {
+                document.getElementById('delete-modal').style.display = 'none';
+            }
+        });
+    </script>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/create_user.html b/templates/create_user.html
new file mode 100644
index 0000000..9480822
--- /dev/null
+++ b/templates/create_user.html
@@ -0,0 +1,44 @@
+{% extends "layout.html" %}
+
+{% block content %}
+<div class="admin-container">
+    <h1>Create New User</h1>
+    
+    {% with messages = get_flashed_messages(with_categories=true) %}
+        {% if messages %}
+            {% for category, message in messages %}
+                <div class="alert alert-{{ category }}">{{ message }}</div>
+            {% endfor %}
+        {% endif %}
+    {% endwith %}
+    
+    <form method="POST" action="{{ url_for('create_user') }}" class="user-form">
+        <div class="form-group">
+            <label for="username">Username</label>
+            <input type="text" id="username" name="username" class="form-control" required autofocus>
+        </div>
+        
+        <div class="form-group">
+            <label for="email">Email</label>
+            <input type="email" id="email" name="email" class="form-control" required>
+        </div>
+        
+        <div class="form-group">
+            <label for="password">Password</label>
+            <input type="password" id="password" name="password" class="form-control" required>
+        </div>
+        
+        <div class="form-group">
+            <label class="checkbox-container">
+                <input type="checkbox" name="is_admin"> Administrator privileges
+                <span class="checkmark"></span>
+            </label>
+        </div>
+        
+        <div class="form-group">
+            <button type="submit" class="btn btn-success">Create User</button>
+            <a href="{{ url_for('admin_users') }}" class="btn btn-secondary">Cancel</a>
+        </div>
+    </form>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/edit_user.html b/templates/edit_user.html
new file mode 100644
index 0000000..1a14590
--- /dev/null
+++ b/templates/edit_user.html
@@ -0,0 +1,44 @@
+{% extends "layout.html" %}
+
+{% block content %}
+<div class="admin-container">
+    <h1>Edit User: {{ user.username }}</h1>
+    
+    {% with messages = get_flashed_messages(with_categories=true) %}
+        {% if messages %}
+            {% for category, message in messages %}
+                <div class="alert alert-{{ category }}">{{ message }}</div>
+            {% endfor %}
+        {% endif %}
+    {% endwith %}
+    
+    <form method="POST" action="{{ url_for('edit_user', user_id=user.id) }}" class="user-form">
+        <div class="form-group">
+            <label for="username">Username</label>
+            <input type="text" id="username" name="username" class="form-control" value="{{ user.username }}" required>
+        </div>
+        
+        <div class="form-group">
+            <label for="email">Email</label>
+            <input type="email" id="email" name="email" class="form-control" value="{{ user.email }}" required>
+        </div>
+        
+        <div class="form-group">
+            <label for="password">New Password (leave blank to keep current)</label>
+            <input type="password" id="password" name="password" class="form-control">
+        </div>
+        
+        <div class="form-group">
+            <label class="checkbox-container">
+                <input type="checkbox" name="is_admin" {% if user.is_admin %}checked{% endif %}> Administrator privileges
+                <span class="checkmark"></span>
+            </label>
+        </div>
+        
+        <div class="form-group">
+            <button type="submit" class="btn btn-primary">Update User</button>
+            <a href="{{ url_for('admin_users') }}" class="btn btn-secondary">Cancel</a>
+        </div>
+    </form>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/layout.html b/templates/layout.html
index aee3363..7883d7d 100644
--- a/templates/layout.html
+++ b/templates/layout.html
@@ -3,7 +3,7 @@
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>TimeTrack - {{ title }}</title>
+    <title>{{ title }} - TimeTrack</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='css/style.css') }}">
 </head>
 <body>
@@ -11,19 +11,48 @@
         <nav>
             <ul>
                 <li><a href="{{ url_for('home') }}">Home</a></li>
-                <li><a href="{{ url_for('history') }}">Complete History</a></li>
-                <li><a href="{{ url_for('config') }}" {% if title == 'Configuration' %}class="active"{% endif %}>Configuration</a></li>
-                <li><a href="{{ url_for('about') }}">About</a></li>
+                {% if g.user %}
+                    <li><a href="{{ url_for('history') }}">History</a></li>
+                    <li><a href="{{ url_for('config') }}">Config</a></li>
+                    <li><a href="{{ url_for('about') }}">About</a></li>
+                    <li><a href="{{ url_for('contact') }}">Contact</a></li>
+                    
+                    <!-- Add Admin dropdown menu here -->
+                    {% if g.user.is_admin %}
+                    <li class="dropdown">
+                        <a href="#" class="dropdown-toggle">Admin</a>
+                        <ul class="dropdown-menu">
+                            <li><a href="{{ url_for('admin_users') }}">User Management</a></li>
+                        </ul>
+                    </li>
+                    {% endif %}
+                    
+                    <li><a href="{{ url_for('profile') }}">Profile</a></li>
+                    <li><a href="{{ url_for('logout') }}">Logout</a></li>
+                {% else %}
+                    <li><a href="{{ url_for('login') }}">Login</a></li>
+                    <li><a href="{{ url_for('register') }}">Register</a></li>
+                {% endif %}
             </ul>
         </nav>
     </header>
 
     <main>
+        {% with messages = get_flashed_messages(with_categories=true) %}
+            {% if messages %}
+                <div class="flash-messages">
+                    {% for category, message in messages %}
+                        <div class="alert alert-{{ category }}">{{ message }}</div>
+                    {% endfor %}
+                </div>
+            {% endif %}
+        {% endwith %}
+        
         {% block content %}{% endblock %}
     </main>
 
     <footer>
-        <p>&copy; 2025 TimeTrack</p>
+        <p>&copy; {{ current_year }} TimeTrack. All rights reserved.</p>
     </footer>
 
     <script src="{{ url_for('static', filename='js/script.js') }}"></script>
diff --git a/templates/login.html b/templates/login.html
new file mode 100644
index 0000000..5656a69
--- /dev/null
+++ b/templates/login.html
@@ -0,0 +1,42 @@
+{% extends "layout.html" %}
+
+{% block content %}
+<div class="auth-container">
+    <h1>Login to TimeTrack</h1>
+    
+    {% with messages = get_flashed_messages(with_categories=true) %}
+        {% if messages %}
+            {% for category, message in messages %}
+                <div class="alert alert-{{ category }}">{{ message }}</div>
+            {% endfor %}
+        {% endif %}
+    {% endwith %}
+    
+    <form method="POST" action="{{ url_for('login') }}" class="auth-form">
+        <div class="form-group">
+            <label for="username">Username</label>
+            <input type="text" id="username" name="username" class="form-control" required autofocus>
+        </div>
+        
+        <div class="form-group">
+            <label for="password">Password</label>
+            <input type="password" id="password" name="password" class="form-control" required>
+        </div>
+        
+        <div class="form-group">
+            <label class="checkbox-container">
+                <input type="checkbox" name="remember"> Remember me
+                <span class="checkmark"></span>
+            </label>
+        </div>
+        
+        <div class="form-group">
+            <button type="submit" class="btn btn-primary">Login</button>
+        </div>
+        
+        <div class="auth-links">
+            <p>Don't have an account? <a href="{{ url_for('register') }}">Register here</a></p>
+        </div>
+    </form>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/profile.html b/templates/profile.html
new file mode 100644
index 0000000..b093036
--- /dev/null
+++ b/templates/profile.html
@@ -0,0 +1,49 @@
+{% extends "layout.html" %}
+
+{% block content %}
+<div class="profile-container">
+    <h1>My Profile</h1>
+    
+    {% with messages = get_flashed_messages(with_categories=true) %}
+        {% if messages %}
+            {% for category, message in messages %}
+                <div class="alert alert-{{ category }}">{{ message }}</div>
+            {% endfor %}
+        {% endif %}
+    {% endwith %}
+    
+    <div class="profile-info">
+        <p><strong>Username:</strong> {{ user.username }}</p>
+        <p><strong>Account Type:</strong> {% if user.is_admin %}Administrator{% else %}User{% endif %}</p>
+        <p><strong>Member Since:</strong> {{ user.created_at.strftime('%Y-%m-%d') }}</p>
+    </div>
+    
+    <h2>Update Profile</h2>
+    <form method="POST" action="{{ url_for('profile') }}" class="profile-form">
+        <div class="form-group">
+            <label for="email">Email</label>
+            <input type="email" id="email" name="email" class="form-control" value="{{ user.email }}" required>
+        </div>
+        
+        <h3>Change Password</h3>
+        <div class="form-group">
+            <label for="current_password">Current Password</label>
+            <input type="password" id="current_password" name="current_password" class="form-control">
+        </div>
+        
+        <div class="form-group">
+            <label for="new_password">New Password</label>
+            <input type="password" id="new_password" name="new_password" class="form-control">
+        </div>
+        
+        <div class="form-group">
+            <label for="confirm_password">Confirm New Password</label>
+            <input type="password" id="confirm_password" name="confirm_password" class="form-control">
+        </div>
+        
+        <div class="form-group">
+            <button type="submit" class="btn btn-primary">Update Profile</button>
+        </div>
+    </form>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/register.html b/templates/register.html
new file mode 100644
index 0000000..367540b
--- /dev/null
+++ b/templates/register.html
@@ -0,0 +1,45 @@
+{% extends "layout.html" %}
+
+{% block content %}
+<div class="auth-container">
+    <h1>Register for TimeTrack</h1>
+    
+    {% with messages = get_flashed_messages(with_categories=true) %}
+        {% if messages %}
+            {% for category, message in messages %}
+                <div class="alert alert-{{ category }}">{{ message }}</div>
+            {% endfor %}
+        {% endif %}
+    {% endwith %}
+    
+    <form method="POST" action="{{ url_for('register') }}" class="auth-form">
+        <div class="form-group">
+            <label for="username">Username</label>
+            <input type="text" id="username" name="username" class="form-control" required autofocus>
+        </div>
+        
+        <div class="form-group">
+            <label for="email">Email</label>
+            <input type="email" id="email" name="email" class="form-control" required>
+        </div>
+        
+        <div class="form-group">
+            <label for="password">Password</label>
+            <input type="password" id="password" name="password" class="form-control" required>
+        </div>
+        
+        <div class="form-group">
+            <label for="confirm_password">Confirm Password</label>
+            <input type="password" id="confirm_password" name="confirm_password" class="form-control" required>
+        </div>
+        
+        <div class="form-group">
+            <button type="submit" class="btn btn-primary">Register</button>
+        </div>
+        
+        <div class="auth-links">
+            <p>Already have an account? <a href="{{ url_for('login') }}">Login here</a></p>
+        </div>
+    </form>
+</div>
+{% endblock %}
\ No newline at end of file