/**
     * Display advanced timetable management interface.
     */
    public function advancedIndex(): View
    {
        $classes = ClassModel::all();
        $sections = Section::all();
        $subjects = Subject::all();
        $teachers = Employee::where('is_teacher', true)->get();
        $rooms = CampusRoom::all();

        // Set up subject colors for consistent color-coding
        $subjectColors = [];
        $colorPalette = ['#3788d8', '#dc3545', '#28a745', '#ffc107', '#17a2b8', '#6f42c1', '#fd7e14', '#e83e8c'];
        $subjectIndex = 0;
        foreach ($subjects as $subject) {
            $subjectColors[$subject->id] = $colorPalette[$subjectIndex % count($colorPalette)];
            $subjectIndex++;
        }

        return view('timetable.advanced_index', compact(
            'classes',
            'sections',
            'subjects',
            'teachers',
            'rooms',
            'subjectColors',
            'selectedClass' => request('class_id'),
            'selectedSection' => request('section_id')
        ));
    }