diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..0812991
Binary files /dev/null and b/.DS_Store differ
diff --git a/log.txt b/log.txt
new file mode 100644
index 0000000..f46dc65
--- /dev/null
+++ b/log.txt
@@ -0,0 +1,35 @@
+commit 08da4605172acdebe2d143f3119b2fc494e9ec9c
+Author: Wind-Explorer <windexplorer@outlook.com>
+Date:   Fri Sep 18 14:40:12 2026 +0800
+
+    update screenshots
+
+commit ee697ecd0817cd3844d20091c5d82a76609da6c6
+Author: Wind-Explorer <windexplorer@outlook.com>
+Date:   Fri Sep 18 14:35:08 2026 +0800
+
+    added modular_auditor.py and updated Dockerfile to use new script
+
+commit 4bae2ce67d91a3ddf003a7e02694b4ee65d97ea9
+Author: Wind-Explorer <windexplorer@outlook.com>
+Date:   Fri Sep 11 14:20:20 2026 +0800
+
+    added README with repo link
+
+commit 692dad6849e6a93c95b23470500e0ec658674e3e
+Author: Wind-Explorer <windexplorer@outlook.com>
+Date:   Fri Sep 11 12:34:59 2026 +0800
+
+    add screenshots
+
+commit 6fb9105403e08e35766978c7d554c16525382e49
+Author: Wind-Explorer <windexplorer@outlook.com>
+Date:   Fri Sep 11 12:34:27 2026 +0800
+
+    add dockerfile
+
+commit 721ad431270886cb85748935e65b90de04001286
+Author: Wind-Explorer <windexplorer@outlook.com>
+Date:   Fri Sep 11 12:21:09 2026 +0800
+
+    init
diff --git a/persist_auditor.py b/persist_auditor.py
new file mode 100644
index 0000000..13efc1b
--- /dev/null
+++ b/persist_auditor.py
@@ -0,0 +1,64 @@
+def get_valid_input():
+    global failed_attempts
+
+    while True:
+        user_input = input("Enter stock quantity: ").strip()
+
+        if user_input.lower() == "quit":
+            return "quit"
+
+        if not user_input.isdigit():
+            print("Error: Invalid input. Please enter a non-negative integer.\n")
+            failed_attempts += 1
+            continue
+
+        quantity = int(user_input)
+
+        if quantity < 0:
+            print("Error: Negative numbers are not allowed.\n")
+            failed_attempts += 1
+            continue
+
+        return quantity
+
+
+def process_delivery(current_total, new_value):
+    return current_total + new_value
+
+
+def calculate_tax(amount):
+    return amount * 0.10
+
+
+def generate_report(total_units, failed_attempts):
+    print("\n--- Audit Report ---")
+    print(f"Total Units Processed: {total_units}")
+    print(f"Failed/Rejected Entries: {failed_attempts}")
+
+
+inventory = 0
+total_units = 0
+failed_attempts = 0
+
+print("=== Stock Auditor ===")
+print("Type 'quit' to exit.\n")
+
+while True:
+    quantity = get_valid_input()
+
+    if quantity == "quit":
+        break
+
+    tax = calculate_tax(quantity)
+
+    inventory = process_delivery(inventory, quantity)
+    total_units = process_delivery(total_units, quantity)
+
+    print(f"Stock added. Current inventory: {inventory}")
+    print(f"Tax on this delivery: ${tax:.2f}\n")
+
+    if inventory > 500:
+        print(f"ALERT: Overstock detected! Inventory ({inventory}) exceeds 500 units.")
+        break
+
+generate_report(total_units, failed_attempts)
diff --git a/persistent_auditor.py b/persistent_auditor.py
new file mode 100644
index 0000000..6cde9f9
--- /dev/null
+++ b/persistent_auditor.py
@@ -0,0 +1,72 @@
+def get_valid_input():
+    global failed_attempts
+
+    while True:
+        user_input = input("Enter stock quantity: ").strip()
+
+        if user_input.lower() == "quit":
+            return "quit"
+
+        if not user_input.isdigit():
+            print("Error: Invalid input. Please enter a non-negative integer.\n")
+            failed_attempts += 1
+            continue
+
+        quantity = int(user_input)
+
+        if quantity < 0:
+            print("Error: Negative numbers are not allowed.\n")
+            failed_attempts += 1
+            continue
+
+        return quantity
+
+
+def process_delivery(current_total, new_value):
+    return current_total + new_value
+
+
+def calculate_tax(amount):
+    return amount * 0.10
+
+
+def generate_report(total_units, failed_attempts):
+    print("\n--- Audit Report ---")
+    print(f"Total Units Processed: {total_units}")
+    print(f"Failed/Rejected Entries: {failed_attempts}")
+
+
+def load_inventory():
+    try:
+        with open("inventory.txt", "r") as inventory_file:
+            return int(inventory_file.readline().strip())
+    except FileNotFoundError:
+        return 0
+
+
+inventory = load_inventory()
+total_units = 0
+failed_attempts = 0
+
+print("=== Stock Auditor ===")
+print("Type 'quit' to exit.\n")
+
+while True:
+    quantity = get_valid_input()
+
+    if quantity == "quit":
+        break
+
+    tax = calculate_tax(quantity)
+
+    inventory = process_delivery(inventory, quantity)
+    total_units = process_delivery(total_units, quantity)
+
+    print(f"Stock added. Current inventory: {inventory}")
+    print(f"Tax on this delivery: ${tax:.2f}\n")
+
+    if inventory > 500:
+        print(f"ALERT: Overstock detected! Inventory ({inventory}) exceeds 500 units.")
+        break
+
+generate_report(total_units, failed_attempts)