# Date Navigation Implementation Learnings

## Implementation Details
- Added left/right arrow navigation to both `StatisticsView.vue` and `BudgetView.vue`
- Used `<van-icon name="arrow-left" />` and `<van-icon name="arrow" />` for directional arrows
- Text center remains clickable for date picker popup
- Arrows use `@click.stop` to prevent event propagation

## StatisticsView.vue
- `navigateDate(direction)` method handles both month and year modes
- Month mode: handles year boundaries (Jan -> Dec of previous year, Dec -> Jan of next year)
- Year mode: increments/decrements year directly
- Resets `showAllExpense` state on navigation

## BudgetView.vue
- `navigateDate(direction)` uses native Date object manipulation
- `setMonth()` automatically handles month/year boundaries
- Updates `selectedDate` ref which triggers data fetching via watcher

## Styling
- Added `.nav-date-picker` with flex layout and 12px gap
- `.nav-date-text` for clickable center text
- `.nav-arrow` with 8px horizontal padding for touch-friendly targets
- Active state opacity transition for visual feedback
- Arrow font size: 18px for clear visibility

## Key Decisions
- Used `@click.stop` on arrows to prevent opening date picker
- Centered layout preserved (van-nav-bar default behavior)
- Consistent styling across both views
- Touch-friendly padding for mobile UX

## Verification
- ESLint: No new errors introduced
- Build: Successful compilation
- Date math: Correctly handles month/year boundaries