diff --git a/app/api/deps.py b/app/api/deps.py
index ae6026b6..6ddae7fd 100644
--- a/app/api/deps.py
+++ b/app/api/deps.py
@@ -328,33 +328,27 @@ def get_current_vendor_api(
 # ============================================================================
 
 
-def get_current_customer_from_cookie_or_header(
-    request: Request,
-    credentials: HTTPAuthorizationCredentials | None = Depends(security),
-    customer_token: str | None = Cookie(None),
-    db: Session = Depends(get_db),
-):
+def _validate_customer_token(token: str, request: Request, db: Session):
     """
-    Get current customer from customer_token cookie or Authorization header.
+    Validate customer JWT token and return Customer object.
 
-    Used for shop account HTML pages (/shop/account/*) that need cookie-based auth.
-    Note: Public shop pages (/shop/products, etc.) don't use this dependency.
-
-    Priority:
-    1. Authorization header (API calls)
-    2. customer_token cookie (page navigation)
+    Validates:
+    1. Token signature and expiration
+    2. Token type is "customer"
+    3. Customer exists and is active
+    4. Token vendor_id matches request vendor (URL-based)
 
     Args:
-        request: FastAPI request
-        credentials: Optional Bearer token from header
-        customer_token: Optional token from customer_token cookie
+        token: JWT token string
+        request: FastAPI request (for vendor context)
         db: Database session
 
     Returns:
         Customer: Authenticated customer object
 
     Raises:
-        InvalidTokenException: If no token or invalid token
+        InvalidTokenException: If token is invalid or expired
+        UnauthorizedVendorAccessException: If vendor mismatch
     """
     from datetime import datetime
 
@@ -362,14 +356,6 @@ def get_current_customer_from_cookie_or_header(
 
     from models.database.customer import Customer
 
-    token, source = _get_token_from_request(
-        credentials, customer_token, "customer_token", str(request.url.path)
-    )
-
-    if not token:
-        logger.warning(f"Customer auth failed: No token for {request.url.path}")
-        raise InvalidTokenException("Customer authentication required")
-
     # Decode and validate customer JWT token
     try:
         payload = jwt.decode(
@@ -394,6 +380,9 @@ def get_current_customer_from_cookie_or_header(
             logger.warning(f"Expired customer token for customer_id={customer_id}")
             raise InvalidTokenException("Token has expired")
 
+        # Get vendor_id from token for validation
+        token_vendor_id = payload.get("vendor_id")
+
     except JWTError as e:
         logger.warning(f"JWT decode error: {str(e)}")
         raise InvalidTokenException("Could not validate credentials")
@@ -409,51 +398,94 @@ def get_current_customer_from_cookie_or_header(
         logger.warning(f"Inactive customer attempted access: {customer.email}")
         raise InvalidTokenException("Customer account is inactive")
 
+    # Validate vendor context matches token
+    # This prevents using a customer token from vendor A on vendor B's shop
+    request_vendor = getattr(request.state, "vendor", None)
+    if request_vendor and token_vendor_id:
+        if request_vendor.id != token_vendor_id:
+            logger.warning(
+                f"Customer {customer.email} token vendor mismatch: "
+                f"token={token_vendor_id}, request={request_vendor.id}"
+            )
+            raise UnauthorizedVendorAccessException(
+                vendor_code=request_vendor.vendor_code,
+                user_id=customer.id,
+            )
+
     logger.debug(f"Customer authenticated: {customer.email} (ID: {customer.id})")
 
     return customer
 
 
-def get_current_customer_api(
-    credentials: HTTPAuthorizationCredentials = Depends(security),
+def get_current_customer_from_cookie_or_header(
+    request: Request,
+    credentials: HTTPAuthorizationCredentials | None = Depends(security),
+    customer_token: str | None = Cookie(None),
     db: Session = Depends(get_db),
-) -> User:
+):
     """
-    Get current customer user from Authorization header ONLY.
+    Get current customer from customer_token cookie or Authorization header.
 
-    Used for shop API endpoints that should not accept cookies.
+    Used for shop account HTML pages (/shop/account/*) that need cookie-based auth.
+    Note: Public shop pages (/shop/products, etc.) don't use this dependency.
+
+    Validates that token vendor_id matches request vendor (URL-based detection).
+
+    Priority:
+    1. Authorization header (API calls)
+    2. customer_token cookie (page navigation)
 
     Args:
+        request: FastAPI request
+        credentials: Optional Bearer token from header
+        customer_token: Optional token from customer_token cookie
+        db: Database session
+
+    Returns:
+        Customer: Authenticated customer object
+
+    Raises:
+        InvalidTokenException: If no token or invalid token
+        UnauthorizedVendorAccessException: If vendor mismatch
+    """
+    token, source = _get_token_from_request(
+        credentials, customer_token, "customer_token", str(request.url.path)
+    )
+
+    if not token:
+        logger.warning(f"Customer auth failed: No token for {request.url.path}")
+        raise InvalidTokenException("Customer authentication required")
+
+    return _validate_customer_token(token, request, db)
+
+
+def get_current_customer_api(
+    request: Request,
+    credentials: HTTPAuthorizationCredentials = Depends(security),
+    db: Session = Depends(get_db),
+):
+    """
+    Get current customer from Authorization header ONLY.
+
+    Used for shop API endpoints that should not accept cookies.
+    Validates that token vendor_id matches request vendor (URL-based detection).
+
+    Args:
+        request: FastAPI request (for vendor context)
         credentials: Bearer token from Authorization header
         db: Database session
 
     Returns:
-        User: Authenticated customer user
+        Customer: Authenticated customer object
 
     Raises:
         InvalidTokenException: If no token or invalid token
-        InsufficientPermissionsException: If user is not customer (admin/vendor blocked)
+        UnauthorizedVendorAccessException: If vendor mismatch
     """
     if not credentials:
         raise InvalidTokenException("Authorization header required for API calls")
 
-    user = _validate_user_token(credentials.credentials, db)
-
-    # Block admins from customer API
-    if user.role == "admin":
-        logger.warning(f"Admin user {user.username} attempted customer API")
-        raise InsufficientPermissionsException("Customer access only")
-
-    # Block vendors from customer API
-    if user.role == "vendor":
-        logger.warning(f"Vendor user {user.username} attempted customer API")
-        raise InsufficientPermissionsException("Customer access only")
-
-    if user.role != "customer":
-        logger.warning(f"Non-customer user {user.username} attempted customer API")
-        raise InsufficientPermissionsException("Customer privileges required")
-
-    return user
+    return _validate_customer_token(credentials.credentials, request, db)
 
 
 # ============================================================================
@@ -883,9 +915,9 @@ def get_current_customer_optional(
     credentials: HTTPAuthorizationCredentials | None = Depends(security),
     customer_token: str | None = Cookie(None),
     db: Session = Depends(get_db),
-) -> User | None:
+):
     """
-    Get current customer user from customer_token cookie or Authorization header.
+    Get current customer from customer_token cookie or Authorization header.
 
     Returns None instead of raising exceptions if not authenticated.
     Used for login pages to check if user is already authenticated.
@@ -901,8 +933,8 @@ def get_current_customer_optional(
         db: Database session
 
     Returns:
-        User: Authenticated customer user if valid token exists
-        None: If no token, invalid token, or user is not customer
+        Customer: Authenticated customer if valid token exists
+        None: If no token, invalid token, or vendor mismatch
     """
     token, source = _get_token_from_request(
         credentials, customer_token, "customer_token", str(request.url.path)
@@ -912,14 +944,8 @@ def get_current_customer_optional(
         return None
 
     try:
-        # Validate token and get user
-        user = _validate_user_token(token, db)
-
-        # Verify user is customer
-        if user.role == "customer":
-            return user
+        # Validate customer token (includes vendor validation)
+        return _validate_customer_token(token, request, db)
     except Exception:
-        # Invalid token or other error
-        pass
-
-    return None
+        # Invalid token, vendor mismatch, or other error
+        return None
diff --git a/app/api/v1/shop/orders.py b/app/api/v1/shop/orders.py
index ea7dd648..23044d8c 100644
--- a/app/api/v1/shop/orders.py
+++ b/app/api/v1/shop/orders.py
@@ -1,23 +1,26 @@
 # app/api/v1/shop/orders.py
 """
-Shop Orders API (Public)
+Shop Orders API (Customer authenticated)
 
-Public endpoints for managing customer orders in shop frontend.
+Endpoints for managing customer orders in shop frontend.
 Uses vendor from request.state (injected by VendorContextMiddleware).
-Requires customer authentication for most operations.
+Requires customer authentication - get_current_customer_api validates
+that customer token vendor_id matches the URL vendor.
+
+Customer Context: get_current_customer_api returns Customer directly
+(not User), with vendor validation already performed.
 """
 
 import logging
 
-from fastapi import APIRouter, Depends, HTTPException, Path, Query, Request
+from fastapi import APIRouter, Depends, Path, Query, Request
 from sqlalchemy.orm import Session
 
 from app.api.deps import get_current_customer_api
 from app.core.database import get_db
-from app.services.customer_service import customer_service
+from app.exceptions import VendorNotFoundException
 from app.services.order_service import order_service
 from models.database.customer import Customer
-from models.database.user import User
 from models.schema.order import (
     OrderCreate,
     OrderDetailResponse,
@@ -29,47 +32,11 @@ router = APIRouter()
 logger = logging.getLogger(__name__)
 
 
-def get_customer_from_user(request: Request, user: User, db: Session) -> Customer:
-    """
-    Helper to get Customer record from authenticated User.
-
-    Args:
-        request: FastAPI request (to get vendor)
-        user: Authenticated user
-        db: Database session
-
-    Returns:
-        Customer record
-
-    Raises:
-        HTTPException: If customer not found or vendor mismatch
-    """
-    vendor = getattr(request.state, "vendor", None)
-
-    if not vendor:
-        raise HTTPException(
-            status_code=404,
-            detail="Vendor not found. Please access via vendor domain/subdomain/path.",
-        )
-
-    # Find customer record for this user and vendor
-    customer = customer_service.get_customer_by_user_id(
-        db=db, vendor_id=vendor.id, user_id=user.id
-    )
-
-    if not customer:
-        raise HTTPException(
-            status_code=404, detail="Customer account not found for current vendor"
-        )
-
-    return customer
-
-
 @router.post("/orders", response_model=OrderResponse)
 def place_order(
     request: Request,
     order_data: OrderCreate,
-    current_user: User = Depends(get_current_customer_api),
+    customer: Customer = Depends(get_current_customer_api),
     db: Session = Depends(get_db),
 ):
     """
@@ -82,17 +49,11 @@ def place_order(
     Request Body:
     - Order data including shipping address, payment method, etc.
     """
-    # Get vendor from middleware
+    # Get vendor from middleware (already validated by get_current_customer_api)
     vendor = getattr(request.state, "vendor", None)
 
     if not vendor:
-        raise HTTPException(
-            status_code=404,
-            detail="Vendor not found. Please access via vendor domain/subdomain/path.",
-        )
-
-    # Get customer record
-    customer = get_customer_from_user(request, current_user, db)
+        raise VendorNotFoundException("context", identifier_type="subdomain")
 
     logger.debug(
         f"[SHOP_API] place_order for customer {customer.id}",
@@ -100,7 +61,6 @@ def place_order(
             "vendor_id": vendor.id,
             "vendor_code": vendor.subdomain,
             "customer_id": customer.id,
-            "user_id": current_user.id,
         },
     )
 
@@ -132,7 +92,7 @@ def get_my_orders(
     request: Request,
     skip: int = Query(0, ge=0),
     limit: int = Query(50, ge=1, le=100),
-    current_user: User = Depends(get_current_customer_api),
+    customer: Customer = Depends(get_current_customer_api),
     db: Session = Depends(get_db),
 ):
     """
@@ -145,17 +105,11 @@ def get_my_orders(
     - skip: Number of orders to skip (pagination)
     - limit: Maximum number of orders to return
     """
-    # Get vendor from middleware
+    # Get vendor from middleware (already validated by get_current_customer_api)
     vendor = getattr(request.state, "vendor", None)
 
     if not vendor:
-        raise HTTPException(
-            status_code=404,
-            detail="Vendor not found. Please access via vendor domain/subdomain/path.",
-        )
-
-    # Get customer record
-    customer = get_customer_from_user(request, current_user, db)
+        raise VendorNotFoundException("context", identifier_type="subdomain")
 
     logger.debug(
         f"[SHOP_API] get_my_orders for customer {customer.id}",
@@ -185,7 +139,7 @@ def get_my_orders(
 def get_order_details(
     request: Request,
     order_id: int = Path(..., description="Order ID", gt=0),
-    current_user: User = Depends(get_current_customer_api),
+    customer: Customer = Depends(get_current_customer_api),
     db: Session = Depends(get_db),
 ):
     """
@@ -197,17 +151,11 @@ def get_order_details(
     Path Parameters:
     - order_id: ID of the order to retrieve
     """
-    # Get vendor from middleware
+    # Get vendor from middleware (already validated by get_current_customer_api)
     vendor = getattr(request.state, "vendor", None)
 
     if not vendor:
-        raise HTTPException(
-            status_code=404,
-            detail="Vendor not found. Please access via vendor domain/subdomain/path.",
-        )
-
-    # Get customer record
-    customer = get_customer_from_user(request, current_user, db)
+        raise VendorNotFoundException("context", identifier_type="subdomain")
 
     logger.debug(
         f"[SHOP_API] get_order_details: order {order_id}",
diff --git a/app/templates/shop/errors/400.html b/app/templates/shop/errors/400.html
index cba0c209..fc16ad74 100644
--- a/app/templates/shop/errors/400.html
+++ b/app/templates/shop/errors/400.html
@@ -1,33 +1,22 @@
+{# app/templates/shop/errors/400.html #}
+{# 400 Bad Request error page #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}❌{% endblock %}
 
 {% block title %}400 - Invalid Request{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
+{% block action_buttons %}
+<a href="javascript:history.back()"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Go Back
+</a>
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Go to Home
+</a>
+{% endblock %}
 
-<div class="error-icon">❌</div>
-<div class="status-code">400</div>
-<div class="status-name">Invalid Request</div>
-<div class="error-message">
-    The request couldn't be processed. This might be due to invalid information or a technical issue.
-</div>
-
-<div class="action-buttons">
-    <a href="javascript:history.back()" class="btn btn-primary">Go Back</a>
-    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
-</div>
-
-<div class="support-link">
-    Need help? <a href="{{ base_url }}shop/contact">Contact us</a>
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+Need help? <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">Contact us</a>
+{% endblock %}
diff --git a/app/templates/shop/errors/401.html b/app/templates/shop/errors/401.html
index 2b138273..a47c3634 100644
--- a/app/templates/shop/errors/401.html
+++ b/app/templates/shop/errors/401.html
@@ -1,33 +1,22 @@
+{# app/templates/shop/errors/401.html #}
+{# 401 Unauthorized error page - prompts login #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}🔐{% endblock %}
 
 {% block title %}401 - Authentication Required{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
+{% block action_buttons %}
+<a href="{{ base_url }}shop/account/login"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Log In
+</a>
+<a href="{{ base_url }}shop/account/register"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Create Account
+</a>
+{% endblock %}
 
-<div class="error-icon">🔐</div>
-<div class="status-code">401</div>
-<div class="status-name">Please Log In</div>
-<div class="error-message">
-    You need to be logged in to access this page. Please sign in to continue shopping.
-</div>
-
-<div class="action-buttons">
-    <a href="{{ base_url }}shop/account/login" class="btn btn-primary">Log In</a>
-    <a href="{{ base_url }}shop/account/register" class="btn btn-secondary">Create Account</a>
-</div>
-
-<div class="support-link">
-    Don't have an account? <a href="{{ base_url }}shop/account/register">Sign up now</a>
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+Don't have an account? <a href="{{ base_url }}shop/account/register" class="text-theme-primary font-semibold hover:underline">Sign up now</a>
+{% endblock %}
diff --git a/app/templates/shop/errors/403.html b/app/templates/shop/errors/403.html
index d2b9ac20..1c4fb43d 100644
--- a/app/templates/shop/errors/403.html
+++ b/app/templates/shop/errors/403.html
@@ -1,33 +1,22 @@
+{# app/templates/shop/errors/403.html #}
+{# 403 Forbidden error page - access restricted #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}🔒{% endblock %}
 
 {% block title %}403 - Access Restricted{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
+{% block action_buttons %}
+<a href="{{ base_url }}shop/account/login"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Log In
+</a>
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Go to Home
+</a>
+{% endblock %}
 
-<div class="error-icon">🔒</div>
-<div class="status-code">403</div>
-<div class="status-name">Access Restricted</div>
-<div class="error-message">
-    This page requires authentication or special permissions to access. Please log in to continue.
-</div>
-
-<div class="action-buttons">
-    <a href="{{ base_url }}shop/account/login" class="btn btn-primary">Log In</a>
-    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
-</div>
-
-<div class="support-link">
-    Need help accessing your account? <a href="{{ base_url }}shop/contact">Contact support</a>
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+Need help accessing your account? <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">Contact support</a>
+{% endblock %}
diff --git a/app/templates/shop/errors/404.html b/app/templates/shop/errors/404.html
index 993f1cd2..16c59372 100644
--- a/app/templates/shop/errors/404.html
+++ b/app/templates/shop/errors/404.html
@@ -1,33 +1,22 @@
+{# app/templates/shop/errors/404.html #}
+{# 404 Not Found error page - uses base template with custom icon and message #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}🔍{% endblock %}
 
 {% block title %}404 - Page Not Found{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
+{% block action_buttons %}
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Continue Shopping
+</a>
+<a href="{{ base_url }}shop/products"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    View All Products
+</a>
+{% endblock %}
 
-<div class="error-icon">🔍</div>
-<div class="status-code">404</div>
-<div class="status-name">Page Not Found</div>
-<div class="error-message">
-    Sorry, we couldn't find the page you're looking for. The product or page may have been moved or is no longer available.
-</div>
-
-<div class="action-buttons">
-    <a href="{{ base_url }}shop/" class="btn btn-primary">Continue Shopping</a>
-    <a href="{{ base_url }}shop/products" class="btn btn-secondary">View All Products</a>
-</div>
-
-<div class="support-link">
-    Can't find what you're looking for? <a href="{{ base_url }}shop/contact">Contact us</a> and we'll help you find it.
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
+{% block support_link %}
+Can't find what you're looking for? <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">Contact us</a> and we'll help you find it.
 {% endblock %}
\ No newline at end of file
diff --git a/app/templates/shop/errors/422.html b/app/templates/shop/errors/422.html
index 95579166..481e4ceb 100644
--- a/app/templates/shop/errors/422.html
+++ b/app/templates/shop/errors/422.html
@@ -1,46 +1,35 @@
+{# app/templates/shop/errors/422.html #}
+{# 422 Unprocessable Entity error page - validation errors #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}📝{% endblock %}
 
 {% block title %}422 - Invalid Information{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
-
-<div class="error-icon">📝</div>
-<div class="status-code">422</div>
-<div class="status-name">Please Check Your Information</div>
-<div class="error-message">
-    Some of the information you provided isn't valid. Please review the form and try again.
-</div>
-
+{% block extra_content %}
 {% if details and details.validation_errors %}
-<div style="margin: 2rem auto; max-width: 400px; text-align: left; background: #fef2f2; padding: 1.5rem; border-radius: 0.75rem; border-left: 4px solid var(--color-primary);">
-    <h3 style="color: var(--color-text); font-size: 0.875rem; margin-bottom: 0.75rem; font-weight: 600;">Please correct:</h3>
-    <ul style="list-style: none; padding: 0; margin: 0;">
+<div class="my-8 mx-auto max-w-md text-left bg-red-50 p-6 rounded-xl border-l-4 border-theme-primary">
+    <h3 class="text-gray-700 text-sm mb-3 font-semibold">Please correct:</h3>
+    <ul class="list-none p-0 m-0">
     {% for error in details.validation_errors %}
-        <li style="margin-bottom: 0.5rem; color: #7f1d1d; font-size: 0.875rem;">
-            • {{ error.msg }}
-        </li>
+        <li class="mb-2 text-red-800 text-sm">• {{ error.msg }}</li>
     {% endfor %}
     </ul>
 </div>
 {% endif %}
+{% endblock %}
 
-<div class="action-buttons">
-    <a href="javascript:history.back()" class="btn btn-primary">Go Back and Fix</a>
-    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
-</div>
+{% block action_buttons %}
+<a href="javascript:history.back()"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Go Back and Fix
+</a>
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Go to Home
+</a>
+{% endblock %}
 
-<div class="support-link">
-    Having trouble? <a href="{{ base_url }}shop/contact">We're here to help</a>
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+Having trouble? <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">We're here to help</a>
+{% endblock %}
diff --git a/app/templates/shop/errors/429.html b/app/templates/shop/errors/429.html
index fa847eeb..7ac2a67f 100644
--- a/app/templates/shop/errors/429.html
+++ b/app/templates/shop/errors/429.html
@@ -1,41 +1,32 @@
+{# app/templates/shop/errors/429.html #}
+{# 429 Too Many Requests error page - rate limiting #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}⏱️{% endblock %}
 
 {% block title %}429 - Please Slow Down{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
-
-<div class="error-icon">⏱️</div>
-<div class="status-code">429</div>
-<div class="status-name">Please Slow Down</div>
-<div class="error-message">
-    You're browsing a bit too fast! Please wait a moment before continuing.
-</div>
-
+{% block extra_content %}
 {% if details and details.retry_after %}
-<div style="margin: 1.5rem 0; padding: 1rem; background: #fef3c7; border-radius: 0.75rem;">
-    <p style="color: #92400e; font-weight: 600;">
+<div class="my-6 p-4 bg-amber-50 rounded-xl">
+    <p class="text-amber-800 font-semibold">
         Please wait {{ details.retry_after }} seconds
     </p>
 </div>
 {% endif %}
+{% endblock %}
 
-<div class="action-buttons">
-    <a href="javascript:location.reload()" class="btn btn-primary">Try Again</a>
-    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
-</div>
+{% block action_buttons %}
+<a href="javascript:location.reload()"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Try Again
+</a>
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Go to Home
+</a>
+{% endblock %}
 
-<div class="support-link">
-    Questions? <a href="{{ base_url }}shop/contact">Contact us</a>
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+Questions? <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">Contact us</a>
+{% endblock %}
diff --git a/app/templates/shop/errors/500.html b/app/templates/shop/errors/500.html
index 12f190ed..892eb90a 100644
--- a/app/templates/shop/errors/500.html
+++ b/app/templates/shop/errors/500.html
@@ -1,33 +1,22 @@
+{# app/templates/shop/errors/500.html #}
+{# 500 Internal Server Error page #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}😔{% endblock %}
 
 {% block title %}500 - Something Went Wrong{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
+{% block action_buttons %}
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Go to Home
+</a>
+<a href="javascript:location.reload()"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Try Again
+</a>
+{% endblock %}
 
-<div class="error-icon">😔</div>
-<div class="status-code">500</div>
-<div class="status-name">Oops! Something Went Wrong</div>
-<div class="error-message">
-    We're experiencing technical difficulties. Our team has been notified and is working to fix the issue. Please try again in a few moments.
-</div>
-
-<div class="action-buttons">
-    <a href="{{ base_url }}shop/" class="btn btn-primary">Go to Home</a>
-    <a href="javascript:location.reload()" class="btn btn-secondary">Try Again</a>
-</div>
-
-<div class="support-link">
-    Issue persisting? <a href="{{ base_url }}shop/contact">Let us know</a> and we'll help you out.
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+Issue persisting? <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">Let us know</a> and we'll help you out.
+{% endblock %}
diff --git a/app/templates/shop/errors/502.html b/app/templates/shop/errors/502.html
index 09ada9e6..88a89f25 100644
--- a/app/templates/shop/errors/502.html
+++ b/app/templates/shop/errors/502.html
@@ -1,33 +1,22 @@
+{# app/templates/shop/errors/502.html #}
+{# 502 Bad Gateway error page - upstream service unavailable #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}🔧{% endblock %}
 
 {% block title %}502 - Service Temporarily Unavailable{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
+{% block action_buttons %}
+<a href="javascript:location.reload()"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Try Again
+</a>
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Go to Home
+</a>
+{% endblock %}
 
-<div class="error-icon">🔧</div>
-<div class="status-code">502</div>
-<div class="status-name">Temporarily Unavailable</div>
-<div class="error-message">
-    We're having trouble connecting to our systems. This is usually temporary. Please try again in a few moments.
-</div>
-
-<div class="action-buttons">
-    <a href="javascript:location.reload()" class="btn btn-primary">Try Again</a>
-    <a href="{{ base_url }}shop/" class="btn btn-secondary">Go to Home</a>
-</div>
-
-<div class="support-link">
-    If this continues, <a href="{{ base_url }}shop/contact">let us know</a>
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+If this continues, <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">let us know</a>
+{% endblock %}
diff --git a/app/templates/shop/errors/generic.html b/app/templates/shop/errors/generic.html
index 250b0dbc..19be08e0 100644
--- a/app/templates/shop/errors/generic.html
+++ b/app/templates/shop/errors/generic.html
@@ -1,31 +1,22 @@
+{# app/templates/shop/errors/generic.html #}
+{# Generic error page - fallback for any error code #}
 {% extends "shop/errors/base.html" %}
 
 {% block icon %}⚠️{% endblock %}
 
 {% block title %}{{ status_code }} - {{ status_name }}{% endblock %}
 
-{% block content %}
-{% if vendor and theme and theme.branding and theme.branding.logo %}
-<img src="{{ theme.branding.logo }}" alt="{{ vendor.name }}" class="vendor-logo">
-{% endif %}
+{% block action_buttons %}
+<a href="{{ base_url }}shop/"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-white bg-theme-primary hover:opacity-90 hover:-translate-y-0.5 transition-all shadow-lg">
+    Continue Shopping
+</a>
+<a href="javascript:history.back()"
+   class="inline-flex items-center px-8 py-4 rounded-xl font-semibold text-theme-primary border-2 border-theme-primary hover:bg-theme-primary hover:text-white hover:-translate-y-0.5 transition-all">
+    Go Back
+</a>
+{% endblock %}
 
-<div class="error-icon">⚠️</div>
-<div class="status-code">{{ status_code }}</div>
-<div class="status-name">{{ status_name }}</div>
-<div class="error-message">{{ message }}</div>
-
-<div class="action-buttons">
-    <a href="{{ base_url }}shop/" class="btn btn-primary">Continue Shopping</a>
-    <a href="javascript:history.back()" class="btn btn-secondary">Go Back</a>
-</div>
-
-<div class="support-link">
-    Need assistance? <a href="{{ base_url }}shop/contact">Contact us</a>
-</div>
-
-{% if vendor %}
-<div class="vendor-info">
-    {{ vendor.name }}
-</div>
-{% endif %}
-{% endblock %}
\ No newline at end of file
+{% block support_link %}
+Need assistance? <a href="{{ base_url }}shop/contact" class="text-theme-primary font-semibold hover:underline">Contact us</a>
+{% endblock %}
diff --git a/docs/api/authentication-quick-reference.md b/docs/api/authentication-quick-reference.md
index 46b03cf5..50bd8399 100644
--- a/docs/api/authentication-quick-reference.md
+++ b/docs/api/authentication-quick-reference.md
@@ -14,6 +14,7 @@ from app.api.deps import (
     get_current_vendor_from_cookie_or_header,
     get_current_customer_from_cookie_or_header
 )
+from models.database.customer import Customer
 
 # Admin page
 @router.get("/admin/dashboard")
@@ -25,10 +26,10 @@ def admin_page(user: User = Depends(get_current_admin_from_cookie_or_header)):
 def vendor_page(user: User = Depends(get_current_vendor_from_cookie_or_header)):
     pass
 
-# Customer page
+# Customer page - NOTE: Returns Customer, not User!
 @router.get("/shop/account/dashboard")
-def customer_page(user: User = Depends(get_current_customer_from_cookie_or_header)):
-    pass
+def customer_page(customer: Customer = Depends(get_current_customer_from_cookie_or_header)):
+    pass  # customer.id, customer.email, customer.vendor_id
 ```
 
 ### For API Endpoints (header only - better security)
@@ -39,6 +40,7 @@ from app.api.deps import (
     get_current_vendor_api,
     get_current_customer_api
 )
+from models.database.customer import Customer
 
 # Admin API
 @router.post("/api/v1/admin/vendors")
@@ -46,14 +48,14 @@ def admin_api(user: User = Depends(get_current_admin_api)):
     pass
 
 # Vendor API
-@router.post("/api/v1/vendor/{code}/products")
+@router.post("/api/v1/vendor/products")
 def vendor_api(user: User = Depends(get_current_vendor_api)):
-    pass
+    pass  # user.token_vendor_id for vendor context
 
-# Customer API
+# Customer API - NOTE: Returns Customer, not User!
 @router.post("/api/v1/shop/orders")
-def customer_api(user: User = Depends(get_current_customer_api)):
-    pass
+def customer_api(request: Request, customer: Customer = Depends(get_current_customer_api)):
+    pass  # customer.id, request.state.vendor validated to match
 ```
 
 ---
diff --git a/docs/api/authentication.md b/docs/api/authentication.md
index a51a4e9b..044ca0e0 100644
--- a/docs/api/authentication.md
+++ b/docs/api/authentication.md
@@ -467,30 +467,51 @@ current_user: User = Depends(get_current_vendor_api)
 
 **Purpose:** Authenticate customer users for HTML pages
 **Accepts:** Cookie (`customer_token`) OR Authorization header
-**Returns:** `Customer` object
+**Returns:** `Customer` object (from `models.database.customer.Customer`)
 **Raises:**
-- `InvalidTokenException` - No token or invalid token
-- `InsufficientPermissionsException` - User is not customer (admin/vendor blocked)
+- `InvalidTokenException` - No token, invalid token, or not a customer token
+- `UnauthorizedVendorAccessException` - Token vendor_id doesn't match URL vendor
 
-**Note:** The `InsufficientPermissionsException` raised here is from `app.exceptions.auth`, which provides general authentication permission checking. This is distinct from `InsufficientTeamPermissionsException` used for team-specific permissions.
+**Security Features:**
+- **Token type validation:** Only accepts tokens with `type: "customer"` - admin and vendor tokens are rejected
+- **Vendor validation:** Validates that `token.vendor_id` matches `request.state.vendor.id` (URL-based vendor)
+- Prevents cross-vendor token reuse (customer from Vendor A cannot use token on Vendor B's shop)
 
 **Usage:**
 ```python
-current_customer: Customer = Depends(get_current_customer_from_cookie_or_header)
+from models.database.customer import Customer
+
+customer: Customer = Depends(get_current_customer_from_cookie_or_header)
+# Access customer.id, customer.email, customer.vendor_id, etc.
 ```
 
 #### `get_current_customer_api()`
 
 **Purpose:** Authenticate customer users for API endpoints
 **Accepts:** Authorization header ONLY
-**Returns:** `Customer` object
+**Returns:** `Customer` object (from `models.database.customer.Customer`)
 **Raises:**
-- `InvalidTokenException` - No token or invalid token
-- `InsufficientPermissionsException` - User is not customer (admin/vendor blocked)
+- `InvalidTokenException` - No token, invalid token, or not a customer token
+- `UnauthorizedVendorAccessException` - Token vendor_id doesn't match URL vendor
+
+**Security Features:**
+- **Token type validation:** Only accepts tokens with `type: "customer"` - admin and vendor tokens are rejected
+- **Vendor validation:** Validates that `token.vendor_id` matches `request.state.vendor.id` (URL-based vendor)
+- Prevents cross-vendor token reuse
 
 **Usage:**
 ```python
-current_customer: Customer = Depends(get_current_customer_api)
+from models.database.customer import Customer
+
+@router.post("/orders")
+def place_order(
+    request: Request,
+    customer: Customer = Depends(get_current_customer_api),
+    db: Session = Depends(get_db),
+):
+    # customer is a Customer object, not User
+    vendor = request.state.vendor  # Already validated to match token
+    order = order_service.create_order(db, vendor.id, customer.id, ...)
 ```
 
 #### `get_current_user()`
@@ -581,20 +602,26 @@ async def vendor_login_page(
 **Purpose:** Check if customer user is authenticated (without enforcing)
 **Accepts:** Cookie (`customer_token`) OR Authorization header
 **Returns:**
-- `User` object with `role="customer"` if authenticated
-- `None` if no token, invalid token, or user is not customer
+- `Customer` object if authenticated with valid customer token
+- `None` if no token, invalid token, vendor mismatch, or not a customer token
 **Raises:** Never raises exceptions
 
+**Security Features:**
+- Only accepts tokens with `type: "customer"` - admin and vendor tokens return `None`
+- Validates vendor_id in token matches URL vendor - mismatch returns `None`
+
 **Usage:**
 ```python
+from models.database.customer import Customer
+
 # Shop login page redirect
 @router.get("/shop/account/login")
 async def customer_login_page(
     request: Request,
-    current_user: Optional[User] = Depends(get_current_customer_optional)
+    customer: Customer | None = Depends(get_current_customer_optional)
 ):
-    if current_user:
-        # User already logged in, redirect to account page
+    if customer:
+        # Customer already logged in, redirect to account page
         return RedirectResponse(url="/shop/account", status_code=302)
 
     # Not logged in, show login form