# Scroll-to-Place and Highlight Feature

## Overview
Implemented automatic scroll and temporary highlight functionality for newly added places in the TripPlanner timeline.

## Feature Behavior
When a user adds a new place to their trip:
1. **Scroll**: Timeline automatically scrolls to center the newly added place
2. **Highlight**: Place is temporarily highlighted with a glowing ring effect
3. **Auto-remove**: Highlight effect automatically disappears after 2 seconds

## Implementation Details

### 1. State Management (TripPlanner.tsx)
Added two new state variables:
- `newlyAddedPlaceId`: Tracks which place was just added
- `highlightedPlaceId`: Controls which place should show the highlight effect

### 2. Place Addition Flow (TripPlanner.tsx)
Modified `handleAddPlaceToDay()` to:
- Set `newlyAddedPlaceId` when a place is successfully added
- This triggers the scroll and highlight effect after `loadTrip()` completes

### 3. Scroll & Highlight Effect (TripPlanner.tsx)
Added a `useEffect` hook that:
- Watches for `newlyAddedPlaceId` changes
- Waits for the place element to be rendered in the DOM
- Calculates optimal scroll position to center the place
- Smoothly scrolls to the place
- Applies highlight effect
- Automatically removes highlight after 2 seconds

### 4. Visual Highlight (TimelinePlace.tsx)
Updated component to:
- Accept `isHighlighted` prop
- Apply special styling when highlighted:
  - Stronger ring effect (ring-4 vs ring-2)
  - Increased ring opacity (ring-primary/40)
  - Enhanced shadow (shadow-lg)
  - Pulsing glow animation

### 5. Animation (index.css)
Added custom CSS animation:
- `pulse-glow` keyframe animation
- Creates a pulsing glow effect using box-shadow
- Runs 2 times over 1 second each
- Uses primary color with varying opacity

## Technical Highlights

### Robust Element Detection
The scroll function includes retry logic:
- Checks if element ref exists
- Retries after 100ms if not found
- Ensures DOM is fully updated before scrolling

### Smooth User Experience
- Uses `behavior: 'smooth'` for scroll animation
- Centers the place in the viewport for optimal visibility
- Non-intrusive highlight that doesn't interfere with user interaction

### Clean State Management
- Automatically cleans up highlight state after 2 seconds
- Clears `newlyAddedPlaceId` to prevent re-triggering
- Uses timeout cleanup to prevent memory leaks

## Files Modified
1. `/src/pages/TripPlanner.tsx` - Main logic and state management
2. `/src/components/planner/TimelinePlace.tsx` - Visual highlight rendering
3. `/src/index.css` - Custom animation styles

## Testing Recommendations
1. Add a place to any day in the trip
2. Verify timeline scrolls to show the new place
3. Confirm highlight effect appears with glow
4. Check highlight disappears after 2 seconds
5. Test with places added to different time blocks (morning, afternoon, evening)
