Improve this same tracker where needed. Keep any features that already work, and preserve the source items, costs and category budgets.

Make over-budget categories easy to spot with a clear OVER BUDGET label and red highlighting. Use Within budget when spending is at or below the category budget. Have the label and color update when costs change. Make sure new expenses added at the bottom are included in the relevant category summary and overall total automatically. Format money in USD and keep input cells easy to distinguish from formulas.

Give me the revised .xlsx file for Google Sheets and brief instructions for adding a new expense. If these features already work, explain how I can test them instead of making unnecessary changes.
