<?php
session_start();
require_once '../config/database.php';
require_once '../includes/functions.php';

if (!isset($_SESSION['student_id'])) {
    redirect('login.php');
}

$session_id = $_GET['session_id'] ?? null;
if (!$session_id) {
    redirect('dashboard.php');
}

// Get result details
$stmt = $pdo->prepare("
    SELECT 
        r.*,
        es.exam_id,
        es.selected_subjects,
        es.start_time,
        es.end_time,
        es.time_remaining,
        e.name as exam_name,
        e.year as exam_year,
        e.duration as exam_duration,
        TIMESTAMPDIFF(MINUTE, es.start_time, es.end_time) as time_taken_minutes
    FROM results r 
    JOIN exam_sessions es ON r.session_id = es.id 
    JOIN exams e ON es.exam_id = e.id 
    WHERE es.id = ? AND es.student_id = ?
");
$stmt->execute([$session_id, $_SESSION['student_id']]);
$result = $stmt->fetch(PDO::FETCH_ASSOC);

if (!$result) {
    $_SESSION['error'] = "Result not found or you don't have permission to view it!";
    redirect('dashboard.php');
}

// Get selected subjects for this session
$selected_subjects = json_decode($result['selected_subjects'] ?? '[]', true) ?? [];

// Get subject names for display
$subject_names = [];
if (!empty($selected_subjects)) {
    $placeholders = str_repeat('?,', count($selected_subjects) - 1) . '?';
    $stmt = $pdo->prepare("SELECT name FROM subjects WHERE id IN ($placeholders)");
    $stmt->execute($selected_subjects);
    $subject_names = $stmt->fetchAll(PDO::FETCH_COLUMN);
}

// Get detailed question analysis for the selected subjects
$placeholders = str_repeat('?,', count($selected_subjects) - 1) . '?';
$stmt = $pdo->prepare("
    SELECT 
        q.*,
        s.name as subject_name,
        sa.selected_answer,
        sa.is_correct
    FROM questions q 
    LEFT JOIN subjects s ON q.subject_id = s.id
    LEFT JOIN student_answers sa ON q.id = sa.question_id AND sa.session_id = ?
    WHERE q.exam_id = ? AND q.subject_id IN ($placeholders)
    ORDER BY s.name, q.id
");
$stmt->execute(array_merge([$session_id, $result['exam_id']], $selected_subjects));
$questions = $stmt->fetchAll(PDO::FETCH_ASSOC);

// Calculate performance metrics
$total_questions = $result['total_questions'];
$correct_answers = $result['correct_answers'];
$questions_attempted = $result['questions_attempted'];
$percentage = $result['percentage'];
$wrong_answers = $questions_attempted - $correct_answers;
$unattempted = $total_questions - $questions_attempted;

// Calculate subject-wise performance
$subject_performance = [];
foreach ($subject_names as $subject_name) {
    $subject_performance[$subject_name] = [
        'total' => 0,
        'correct' => 0,
        'attempted' => 0
    ];
}

foreach ($questions as $question) {
    $subject_name = $question['subject_name'];
    if (isset($subject_performance[$subject_name])) {
        $subject_performance[$subject_name]['total']++;
        if (!is_null($question['selected_answer'])) {
            $subject_performance[$subject_name]['attempted']++;
            if ($question['is_correct']) {
                $subject_performance[$subject_name]['correct']++;
            }
        }
    }
}

// Determine performance category and color
if ($percentage >= 80) {
    $performance_category = 'Excellent';
    $performance_color = '#27ae60';
    $performance_icon = '🎉';
    $performance_message = 'Outstanding performance! Keep up the great work!';
} elseif ($percentage >= 60) {
    $performance_category = 'Good';
    $performance_color = '#3498db';
    $performance_icon = '👍';
    $performance_message = 'Good job! You are on the right track.';
} elseif ($percentage >= 40) {
    $performance_category = 'Average';
    $performance_color = '#f39c12';
    $performance_icon = '📊';
    $performance_message = 'Average performance. Consider more practice.';
} else {
    $performance_category = 'Needs Improvement';
    $performance_color = '#e74c3c';
    $performance_icon = '💪';
    $performance_message = 'Keep practicing! You can do better next time.';
}

// Calculate time efficiency
$time_efficiency = $result['exam_duration'] > 0 ? 
    (($result['exam_duration'] - ($result['time_remaining'] / 60)) / $result['exam_duration']) * 100 : 0;
$time_efficiency = min(100, $time_efficiency);

// Get student's recent performance for comparison
$stmt = $pdo->prepare("
    SELECT AVG(percentage) as average_score, COUNT(*) as total_exams
    FROM results r 
    JOIN exam_sessions es ON r.session_id = es.id 
    WHERE es.student_id = ? AND es.id != ?
");
$stmt->execute([$_SESSION['student_id'], $session_id]);
$previous_performance = $stmt->fetch(PDO::FETCH_ASSOC);

// Calculate improvement
$improvement = $previous_performance['average_score'] ? 
    $percentage - $previous_performance['average_score'] : 0;
?>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Exam Result - <?php echo htmlspecialchars($result['exam_name']); ?></title>
    <link rel="stylesheet" href="../assets/css/style.css">
    <script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
    <style>
        .result-container {
            background: white;
            border-radius: 15px;
            box-shadow: 0 5px 25px rgba(0,0,0,0.1);
            overflow: hidden;
            margin: 2rem 0;
            max-width: 1200px;
            margin-left: auto;
            margin-right: auto;
        }

        .content-header {
            background: linear-gradient(135deg, #2c3e50, #34495e);
            color: white;
            padding: 2rem;
            text-align: center;
        }

        .content-header h1 {
            margin: 0;
            font-size: 2rem;
            font-weight: 700;
        }

        .content-header p {
            margin: 0.5rem 0 0 0;
            opacity: 0.9;
        }

        .content-body {
            padding: 2rem;
        }

        .back-link {
            color: #3498db;
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            gap: 5px;
            margin-bottom: 1rem;
            font-weight: 600;
        }

        .back-link:hover {
            color: #2980b9;
        }

        /* Summary Section */
        .summary-section {
            text-align: center;
            margin-bottom: 3rem;
            padding: 2rem;
            background: linear-gradient(135deg, #f8f9fa, #e9ecef);
            border-radius: 15px;
        }

        .score-circle {
            width: 200px;
            height: 200px;
            border-radius: 50%;
            background: conic-gradient(<?php echo $performance_color; ?> <?php echo $percentage; ?>%, #e1e8ed 0);
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 2rem;
            position: relative;
            box-shadow: 0 10px 30px rgba(0,0,0,0.1);
        }

        .score-circle::before {
            content: '';
            position: absolute;
            width: 160px;
            height: 160px;
            background: white;
            border-radius: 50%;
        }

        .score-content {
            position: relative;
            z-index: 1;
            text-align: center;
        }

        .score-percentage {
            font-size: 2.5rem;
            font-weight: bold;
            color: #2c3e50;
            margin-bottom: 0.5rem;
        }

        .score-text {
            font-size: 1rem;
            color: #7f8c8d;
            font-weight: 600;
        }

        .performance-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: <?php echo $performance_color; ?>;
            color: white;
            padding: 10px 20px;
            border-radius: 25px;
            font-weight: 600;
            margin-bottom: 1rem;
        }

        .performance-message {
            font-size: 1.1rem;
            color: #2c3e50;
            margin-bottom: 0;
        }

        .selected-subjects {
            margin-top: 1rem;
        }

        .subject-badge {
            display: inline-block;
            background: #3498db;
            color: white;
            padding: 0.3rem 0.8rem;
            border-radius: 15px;
            margin: 0.2rem;
            font-size: 0.8rem;
        }

        /* Statistics Grid */
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1.5rem;
            margin-bottom: 3rem;
        }

        .stat-card {
            background: white;
            padding: 1.5rem;
            border-radius: 10px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            text-align: center;
            border-left: 4px solid #3498db;
        }

        .stat-card.correct { border-left-color: #27ae60; }
        .stat-card.wrong { border-left-color: #e74c3c; }
        .stat-card.unattempted { border-left-color: #95a5a6; }
        .stat-card.time { border-left-color: #f39c12; }

        .stat-number {
            font-size: 2rem;
            font-weight: bold;
            color: #2c3e50;
            margin-bottom: 0.5rem;
        }

        .stat-label {
            color: #7f8c8d;
            font-size: 0.9rem;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }

        /* Charts Section */
        .charts-section {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2rem;
            margin-bottom: 3rem;
        }

        .chart-card {
            background: white;
            padding: 1.5rem;
            border-radius: 10px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
        }

        .chart-card h3 {
            color: #2c3e50;
            margin-bottom: 1rem;
            font-size: 1.1rem;
            text-align: center;
        }

        /* Subject Performance */
        .subject-performance {
            background: white;
            padding: 1.5rem;
            border-radius: 10px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            margin-bottom: 2rem;
        }

        .subject-performance h3 {
            color: #2c3e50;
            margin-bottom: 1.5rem;
            font-size: 1.3rem;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .subject-performance h3::before {
            content: '📚';
            font-size: 1.2rem;
        }

        .subject-stats {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 1rem;
        }

        .subject-stat {
            padding: 1rem;
            border-radius: 8px;
            background: #f8f9fa;
            border-left: 4px solid #3498db;
        }

        .subject-stat h4 {
            margin: 0 0 0.5rem 0;
            color: #2c3e50;
            font-size: 1rem;
        }

        .subject-stat .progress {
            height: 8px;
            background: #e1e8ed;
            border-radius: 4px;
            overflow: hidden;
            margin-bottom: 0.5rem;
        }

        .subject-stat .progress-bar {
            height: 100%;
            background: #27ae60;
            border-radius: 4px;
        }

        .subject-stat .stats {
            display: flex;
            justify-content: space-between;
            font-size: 0.9rem;
            color: #7f8c8d;
        }

        /* Detailed Analysis */
        .analysis-section {
            background: white;
            padding: 2rem;
            border-radius: 10px;
            box-shadow: 0 3px 10px rgba(0,0,0,0.08);
            margin-bottom: 2rem;
        }

        .analysis-section h3 {
            color: #2c3e50;
            margin-bottom: 1.5rem;
            font-size: 1.3rem;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .analysis-section h3::before {
            content: '📊';
            font-size: 1.2rem;
        }

        .questions-list {
            display: grid;
            gap: 1rem;
        }

        .question-item {
            border: 2px solid #e1e8ed;
            border-radius: 10px;
            padding: 1.5rem;
            background: #f8f9fa;
            transition: all 0.3s ease;
        }

        .question-item.correct {
            border-color: #27ae60;
            background: #f8fff9;
        }

        .question-item.incorrect {
            border-color: #e74c3c;
            background: #fdf2f2;
        }

        .question-item.unattempted {
            border-color: #95a5a6;
            background: #f8f9fa;
            opacity: 0.7;
        }

        .question-header {
            display: flex;
            justify-content: space-between;
            align-items: flex-start;
            margin-bottom: 1rem;
            gap: 1rem;
        }

        .question-text {
            flex: 1;
            font-weight: 600;
            color: #2c3e50;
            font-size: 1rem;
        }

        .question-meta {
            display: flex;
            gap: 1rem;
            align-items: center;
        }

        .question-subject {
            background: #3498db;
            color: white;
            padding: 4px 8px;
            border-radius: 12px;
            font-size: 0.8rem;
            font-weight: 500;
        }

        .question-status {
            padding: 6px 12px;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
            text-transform: uppercase;
            white-space: nowrap;
        }

        .status-correct { background: #d4edda; color: #155724; }
        .status-incorrect { background: #f8d7da; color: #721c24; }
        .status-unattempted { background: #e2e3e5; color: #383d41; }

        .options-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 0.75rem;
            margin-bottom: 1rem;
        }

        .option {
            padding: 10px 15px;
            border: 2px solid #e1e8ed;
            border-radius: 6px;
            background: white;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .option.correct-answer {
            border-color: #27ae60;
            background: #d4edda;
            font-weight: 600;
        }

        .option.selected-answer {
            border-color: #3498db;
            background: #d1ecf1;
        }

        .option.selected-incorrect {
            border-color: #e74c3c;
            background: #f8d7da;
        }

        .option-letter {
            width: 25px;
            height: 25px;
            border-radius: 50%;
            background: #3498db;
            color: white;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: 600;
            font-size: 0.8rem;
        }

        .option.correct-answer .option-letter {
            background: #27ae60;
        }

        .option.selected-incorrect .option-letter {
            background: #e74c3c;
        }

        .question-explanation {
            margin-top: 1rem;
            padding: 1rem;
            background: white;
            border-radius: 6px;
            border-left: 4px solid #3498db;
        }

        /* Action Buttons */
        .action-buttons {
            display: flex;
            gap: 1rem;
            justify-content: center;
            flex-wrap: wrap;
            padding: 2rem;
            border-top: 1px solid #e1e8ed;
        }

        .btn {
            padding: 12px 25px;
            border: none;
            border-radius: 8px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            text-decoration: none;
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }

        .btn-primary {
            background: #3498db;
            color: white;
        }

        .btn-primary:hover {
            background: #2980b9;
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);
        }

        .btn-success {
            background: #27ae60;
            color: white;
        }

        .btn-success:hover {
            background: #219a52;
            transform: translateY(-2px);
        }

        .btn-secondary {
            background: #95a5a6;
            color: white;
        }

        .btn-secondary:hover {
            background: #7f8c8d;
            transform: translateY(-2px);
        }

        /* Responsive Design */
        @media (max-width: 1024px) {
            .charts-section {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 768px) {
            .content-body {
                padding: 1.5rem;
            }

            .summary-section {
                padding: 1.5rem;
            }

            .score-circle {
                width: 150px;
                height: 150px;
            }

            .score-circle::before {
                width: 120px;
                height: 120px;
            }

            .score-percentage {
                font-size: 2rem;
            }

            .stats-grid {
                grid-template-columns: repeat(2, 1fr);
            }

            .options-grid {
                grid-template-columns: 1fr;
            }

            .action-buttons {
                flex-direction: column;
                align-items: center;
            }

            .btn {
                width: 100%;
                max-width: 300px;
                justify-content: center;
            }

            .question-header {
                flex-direction: column;
                align-items: flex-start;
            }

            .question-meta {
                width: 100%;
                justify-content: space-between;
            }
        }

        @media (max-width: 480px) {
            .content-header {
                padding: 1.5rem;
            }

            .content-header h1 {
                font-size: 1.5rem;
            }

            .stats-grid {
                grid-template-columns: 1fr;
            }

            .score-circle {
                width: 120px;
                height: 120px;
            }

            .score-circle::before {
                width: 90px;
                height: 90px;
            }

            .score-percentage {
                font-size: 1.5rem;
            }
        }
    </style>
</head>
<body>
    <?php include '../includes/header.php'; ?>
    
    <div class="container">
        <a href="dashboard.php" class="back-link">← Back to Dashboard</a>
        
        <div class="result-container">
            <div class="content-header">
                <h1>Exam Result</h1>
                <p><?php echo htmlspecialchars($result['exam_name']); ?> (<?php echo $result['exam_year']; ?>)</p>
                <?php if (!empty($subject_names)): ?>
                    <div class="selected-subjects">
                        <?php foreach ($subject_names as $subject_name): ?>
                            <span class="subject-badge"><?php echo htmlspecialchars($subject_name); ?></span>
                        <?php endforeach; ?>
                    </div>
                <?php endif; ?>
            </div>

            <div class="content-body">
                <!-- Summary Section -->
                <div class="summary-section">
                    <div class="score-circle">
                        <div class="score-content">
                            <div class="score-percentage"><?php echo number_format($percentage, 1); ?>%</div>
                            <div class="score-text">Score</div>
                        </div>
                    </div>
                    
                    <div class="performance-badge">
                        <?php echo $performance_icon; ?> <?php echo $performance_category; ?>
                    </div>
                    <p class="performance-message"><?php echo $performance_message; ?></p>
                </div>

                <!-- Statistics Grid -->
                <div class="stats-grid">
                    <div class="stat-card correct">
                        <div class="stat-number"><?php echo $correct_answers; ?></div>
                        <div class="stat-label">Correct Answers</div>
                    </div>
                    <div class="stat-card wrong">
                        <div class="stat-number"><?php echo $wrong_answers; ?></div>
                        <div class="stat-label">Wrong Answers</div>
                    </div>
                    <div class="stat-card unattempted">
                        <div class="stat-number"><?php echo $unattempted; ?></div>
                        <div class="stat-label">Unattempted</div>
                    </div>
                    <div class="stat-card time">
                        <div class="stat-number">
                            <?php 
                            $time_taken = $result['time_taken_minutes'];
                            if ($time_taken >= 60) {
                                $hours = floor($time_taken / 60);
                                $minutes = $time_taken % 60;
                                echo sprintf('%dh %dm', $hours, $minutes);
                            } else {
                                echo sprintf('%dm', $time_taken);
                            }
                            ?>
                        </div>
                        <div class="stat-label">Time Taken</div>
                    </div>
                </div>

                <!-- Subject Performance -->
                <?php if (!empty($subject_performance)): ?>
                <div class="subject-performance">
                    <h3>Subject-wise Performance</h3>
                    <div class="subject-stats">
                        <?php foreach ($subject_performance as $subject_name => $performance): 
                            if ($performance['total'] > 0) {
                                $percentage = $performance['total'] > 0 ? ($performance['correct'] / $performance['total']) * 100 : 0;
                            } else {
                                $percentage = 0;
                            }
                        ?>
                            <div class="subject-stat">
                                <h4><?php echo htmlspecialchars($subject_name); ?></h4>
                                <div class="progress">
                                    <div class="progress-bar" style="width: <?php echo $percentage; ?>%"></div>
                                </div>
                                <div class="stats">
                                    <span><?php echo number_format($percentage, 1); ?>%</span>
                                    <span><?php echo $performance['correct']; ?>/<?php echo $performance['total']; ?> correct</span>
                                </div>
                            </div>
                        <?php endforeach; ?>
                    </div>
                </div>
                <?php endif; ?>

                <!-- Charts Section -->
                <div class="charts-section">
                    <div class="chart-card">
                        <h3>Score Distribution</h3>
                        <canvas id="scoreDistributionChart" height="250"></canvas>
                    </div>
                    <div class="chart-card">
                        <h3>Performance Overview</h3>
                        <canvas id="performanceChart" height="250"></canvas>
                    </div>
                </div>

                <!-- Detailed Question Analysis -->
                <div class="analysis-section">
                    <h3>Detailed Question Analysis</h3>
                    <div class="questions-list">
                        <?php foreach ($questions as $index => $q): 
                            $is_correct = $q['is_correct'];
                            $is_attempted = !is_null($q['selected_answer']);
                            $item_class = $is_attempted ? ($is_correct ? 'correct' : 'incorrect') : 'unattempted';
                            $status_text = $is_attempted ? ($is_correct ? 'Correct' : 'Incorrect') : 'Unattempted';
                            $status_class = $is_attempted ? ($is_correct ? 'status-correct' : 'status-incorrect') : 'status-unattempted';
                        ?>
                            <div class="question-item <?php echo $item_class; ?>">
                                <div class="question-header">
                                    <div class="question-text">
                                        Q<?php echo $index + 1; ?>: <?php echo htmlspecialchars($q['question_text']); ?>
                                    </div>
                                    <div class="question-meta">
                                        <span class="question-subject"><?php echo htmlspecialchars($q['subject_name']); ?></span>
                                        <div class="question-status <?php echo $status_class; ?>">
                                            <?php echo $status_text; ?>
                                        </div>
                                    </div>
                                </div>

                                <div class="options-grid">
                                    <?php 
                                    $options = [
                                        'A' => $q['option_a'],
                                        'B' => $q['option_b'],
                                        'C' => $q['option_c'],
                                        'D' => $q['option_d']
                                    ];
                                    
                                    foreach ($options as $letter => $option_text): 
                                        $is_correct_option = $letter === $q['correct_answer'];
                                        $is_selected = $q['selected_answer'] === $letter;
                                        $option_class = '';
                                        
                                        if ($is_correct_option) {
                                            $option_class = 'correct-answer';
                                        } elseif ($is_selected && !$is_correct_option) {
                                            $option_class = 'selected-incorrect';
                                        } elseif ($is_selected) {
                                            $option_class = 'selected-answer';
                                        }
                                    ?>
                                        <div class="option <?php echo $option_class; ?>">
                                            <div class="option-letter"><?php echo $letter; ?></div>
                                            <div><?php echo htmlspecialchars($option_text); ?></div>
                                        </div>
                                    <?php endforeach; ?>
                                </div>

                                <?php if ($is_attempted && !$is_correct): ?>
                                    <div class="question-explanation">
                                        <strong>Note:</strong> You selected <strong><?php echo $q['selected_answer']; ?></strong>, 
                                        but the correct answer is <strong><?php echo $q['correct_answer']; ?></strong>.
                                    </div>
                                <?php elseif (!$is_attempted): ?>
                                    <div class="question-explanation">
                                        <strong>Note:</strong> You did not attempt this question. The correct answer is <strong><?php echo $q['correct_answer']; ?></strong>.
                                    </div>
                                <?php endif; ?>
                            </div>
                        <?php endforeach; ?>
                    </div>
                </div>

                <!-- Action Buttons -->
                <div class="action-buttons">
                    <a href="dashboard.php" class="btn btn-secondary">
                        📊 Back to Dashboard
                    </a>
                    <a href="exam_selection.php?exam_id=<?php echo $result['exam_id']; ?>" class="btn btn-primary">
                        🔄 Retake Exam
                    </a>
                    <button onclick="window.print()" class="btn btn-success">
                        🖨️ Print Result
                    </button>
                </div>
            </div>
        </div>
    </div>
 <?php include '../includes/footer.php'; ?>
    <script>
        // Score Distribution Chart
        const scoreDistributionChart = new Chart(
            document.getElementById('scoreDistributionChart'),
            {
                type: 'doughnut',
                data: {
                    labels: ['Correct', 'Wrong', 'Unattempted'],
                    datasets: [{
                        data: [
                            <?php echo $correct_answers; ?>,
                            <?php echo $wrong_answers; ?>,
                            <?php echo $unattempted; ?>
                        ],
                        backgroundColor: [
                            '#27ae60', '#e74c3c', '#95a5a6'
                        ],
                        borderWidth: 0
                    }]
                },
                options: {
                    responsive: true,
                    plugins: {
                        legend: {
                            position: 'bottom'
                        }
                    }
                }
            }
        );

        // Performance Comparison Chart
        const performanceChart = new Chart(
            document.getElementById('performanceChart'),
            {
                type: 'bar',
                data: {
                    labels: ['This Exam', 'Average Score'],
                    datasets: [{
                        label: 'Percentage Score',
                        data: [
                            <?php echo $percentage; ?>,
                            <?php echo $previous_performance['average_score'] ? number_format($previous_performance['average_score'], 1) : $percentage; ?>
                        ],
                        backgroundColor: [
                            '<?php echo $performance_color; ?>',
                            '#3498db'
                        ],
                        borderWidth: 0
                    }]
                },
                options: {
                    responsive: true,
                    plugins: {
                        legend: {
                            display: false
                        }
                    },
                    scales: {
                        y: {
                            beginAtZero: true,
                            max: 100,
                            ticks: {
                                callback: function(value) {
                                    return value + '%';
                                }
                            }
                        }
                    }
                }
            }
        );

        // Print styles
        const style = document.createElement('style');
        style.innerHTML = `
            @media print {
                .back-link, .action-buttons, .btn {
                    display: none !important;
                }
                .result-container {
                    box-shadow: none !important;
                    margin: 0 !important;
                }
                .content-header {
                    background: #2c3e50 !important;
                    -webkit-print-color-adjust: exact;
                }
            }
        `;
        document.head.appendChild(style);
    </script>
</body>
</html>