Build Quiz Comparison Tool

**Title:** Create Side-by-Side Quiz Attempt Comparison Interface

## Problem Statement

Users who retake quizzes cannot easily compare their performance across attempts to identify improvement areas or track progress. A comparison tool would provide valuable insights into learning patterns and effectiveness.

## Proposed Solution

Develop a quiz comparison feature allowing users to:

* Select two quiz attempts to compare
* Side-by-side view of results
* Highlight differences in answers
* Show improvement metrics
* Visualize performance changes
* Export comparison report

## Acceptance Criteria

### ✅ Comparison Selection

* "Compare" button on quiz result cards
* Multi-select mode in quiz history
* Select exactly 2 quizzes to compare
* Validate quizzes are from same category/quiz
* Disable compare if incompatible quizzes selected
* "Compare Selected" button appears when 2 selected

### ✅ Comparison Page Layout

* Split-screen design (50/50)
* Left side: First attempt, Right side: Second attempt
* Synchronized scrolling between panels
* Header showing attempt dates and scores
* Color coding: Blue for attempt 1, Green for attempt 2
* Toggle between split view and overlay view

### ✅ Score Comparison

* Large score displays at top of each panel
* Percentage and absolute score
* Difference calculation (+/- X%)
* Arrow indicators (↑ improved, ↓ declined, → same)
* Score change percentage prominently displayed
* Visual gauge showing improvement

### ✅ Question-by-Question Comparison

* List of questions in order
* Show both attempts' answers side by side
* Highlight differences in red/green
* Correct answer displayed
* Indicators:
- ✓✓ Both correct
- ✗✗ Both incorrect
- ✓✗ First correct, second incorrect
- ✗✓ First incorrect, second correct
* Time spent on each question (both attempts)

### ✅ Performance Metrics

* Overall accuracy change (%)
* Questions improved count
* Questions declined count
* Consistent correct answers count
* Consistent incorrect answers count
* Average time per question change
* Total time comparison

### ✅ Visualization Charts

* Bar chart comparing scores
* Line graph showing progression (if >2 attempts)
* Pie chart of question outcome distribution
* Radar chart for category-wise comparison (if applicable)
* Time spent comparison chart

### ✅ Improvement Analysis

* "Areas of Improvement" section
* List questions that improved with explanations
* "Areas Needing Work" section
* List questions that declined
* "Consistently Strong" - questions correct both times
* "Consistently Weak" - questions incorrect both times
* Suggestions for topics to study

### ✅ Export Comparison

* Download comparison as PDF
* Include all metrics and charts
* Professional formatting
* Date of comparison in filename
* Option to include/exclude question details

### ✅ Additional Features

* Compare button in quiz history filters
* "Compare with average" option
* Compare with best attempt
* Multiple attempts timeline view
* Bookmark comparison for later review