Write SQL query to solve given problem: Calculate the difference between the total sales in the East superstore and the total sales in the West superstore.. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT SUM(T1.Sales) - SUM(T2.Sales) AS difference FROM east_superstore AS T1 INNER JOIN west_superstore AS T2 ON T1.`Customer ID` = T2.`Customer ID`