diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..60e6379
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,11 @@
+# Configuration de l'application
+FLASK_ENV=development
+SECRET_KEY=your-very-secure-secret-key-here-change-this
+DATABASE_URL=sqlite:///school_management.db
+
+# Base de données
+DB_ECHO=false
+
+# Optionnel: pour la production
+# FLASK_ENV=production
+# DATABASE_URL=postgresql://user:password@localhost/dbname
\ No newline at end of file
diff --git a/app.py b/app.py
index 42303b4..9f55594 100644
--- a/app.py
+++ b/app.py
@@ -1,17 +1,35 @@
+import os
+import logging
 from flask import Flask, render_template
 from models import db, Assessment, Student, ClassGroup
 from commands import init_db
+from config import config
 
 # Import blueprints
 from routes.assessments import bp as assessments_bp
 from routes.exercises import bp as exercises_bp
 from routes.grading import bp as grading_bp
 
-def create_app():
+def create_app(config_name=None):
+    if config_name is None:
+        config_name = os.environ.get('FLASK_ENV', 'development')
+    
     app = Flask(__name__)
-    app.config['SECRET_KEY'] = 'your-secret-key-here'
-    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///school_management.db'
-    app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
+    app.config.from_object(config[config_name])
+    
+    # Configuration du logging
+    if not app.debug and not app.testing:
+        if not os.path.exists('logs'):
+            os.mkdir('logs')
+        
+        file_handler = logging.FileHandler('logs/school_management.log')
+        file_handler.setFormatter(logging.Formatter(
+            '%(asctime)s %(levelname)s: %(message)s [in %(pathname)s:%(lineno)d]'
+        ))
+        file_handler.setLevel(logging.INFO)
+        app.logger.addHandler(file_handler)
+        app.logger.setLevel(logging.INFO)
+        app.logger.info('Application de gestion scolaire démarrée')
 
     # Initialize extensions
     db.init_app(app)
@@ -27,25 +45,41 @@ def create_app():
     # Main routes
     @app.route('/')
     def index():
-        recent_assessments = Assessment.query.order_by(Assessment.date.desc()).limit(5).all()
-        total_students = Student.query.count()
-        total_assessments = Assessment.query.count()
-        total_classes = ClassGroup.query.count()
-        return render_template('index.html', 
-                             recent_assessments=recent_assessments,
-                             total_students=total_students,
-                             total_assessments=total_assessments,
-                             total_classes=total_classes)
+        try:
+            recent_assessments = Assessment.query.order_by(Assessment.date.desc()).limit(5).all()
+            total_students = Student.query.count()
+            total_assessments = Assessment.query.count()
+            total_classes = ClassGroup.query.count()
+            return render_template('index.html', 
+                                 recent_assessments=recent_assessments,
+                                 total_students=total_students,
+                                 total_assessments=total_assessments,
+                                 total_classes=total_classes)
+        except Exception as e:
+            app.logger.error(f'Erreur lors du chargement de la page d\'accueil: {e}')
+            return render_template('error.html', error="Erreur lors du chargement de la page"), 500
 
     @app.route('/classes')
     def classes():
-        classes = ClassGroup.query.order_by(ClassGroup.year, ClassGroup.name).all()
-        return render_template('classes.html', classes=classes)
+        try:
+            classes = ClassGroup.query.order_by(ClassGroup.year, ClassGroup.name).all()
+            return render_template('classes.html', classes=classes)
+        except Exception as e:
+            app.logger.error(f'Erreur lors du chargement des classes: {e}')
+            return render_template('error.html', error="Erreur lors du chargement des classes"), 500
 
     @app.route('/students')
     def students():
-        students = Student.query.join(ClassGroup).order_by(ClassGroup.name, Student.last_name, Student.first_name).all()
-        return render_template('students.html', students=students)
+        try:
+            # Optimisation: utiliser joinedload pour éviter les requêtes N+1
+            from sqlalchemy.orm import joinedload
+            students = Student.query.options(joinedload(Student.class_group)).order_by(
+                ClassGroup.name, Student.last_name, Student.first_name
+            ).join(ClassGroup).all()
+            return render_template('students.html', students=students)
+        except Exception as e:
+            app.logger.error(f'Erreur lors du chargement des étudiants: {e}')
+            return render_template('error.html', error="Erreur lors du chargement des étudiants"), 500
 
     return app
 
@@ -53,4 +87,7 @@ if __name__ == '__main__':
     app = create_app()
     with app.app_context():
         db.create_all()
-    app.run(debug=True)
\ No newline at end of file
+    
+    # Le mode debug est géré par la configuration
+    port = int(os.environ.get('PORT', 5000))
+    app.run(host='0.0.0.0', port=port)
\ No newline at end of file
diff --git a/config.py b/config.py
new file mode 100644
index 0000000..b5c3478
--- /dev/null
+++ b/config.py
@@ -0,0 +1,44 @@
+import os
+from datetime import timedelta
+
+class Config:
+    """Configuration de base"""
+    SECRET_KEY = os.environ.get('SECRET_KEY') or os.urandom(32)
+    SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL') or 'sqlite:///school_management.db'
+    SQLALCHEMY_TRACK_MODIFICATIONS = False
+    WTF_CSRF_TIME_LIMIT = timedelta(hours=1)
+    
+class DevelopmentConfig(Config):
+    """Configuration pour le développement"""
+    DEBUG = True
+    SQLALCHEMY_ECHO = os.environ.get('DB_ECHO', 'False').lower() == 'true'
+
+class ProductionConfig(Config):
+    """Configuration pour la production"""
+    DEBUG = False
+    SQLALCHEMY_ECHO = False
+    
+    @classmethod
+    def init_app(cls, app):
+        Config.init_app(app)
+        
+        # Log vers stderr en production
+        import logging
+        from logging import StreamHandler
+        file_handler = StreamHandler()
+        file_handler.setLevel(logging.WARNING)
+        app.logger.addHandler(file_handler)
+
+class TestingConfig(Config):
+    """Configuration pour les tests"""
+    TESTING = True
+    SQLALCHEMY_DATABASE_URI = 'sqlite:///:memory:'
+    WTF_CSRF_ENABLED = False
+    DEBUG = True
+
+config = {
+    'development': DevelopmentConfig,
+    'production': ProductionConfig,
+    'testing': TestingConfig,
+    'default': DevelopmentConfig
+}
\ No newline at end of file
diff --git a/forms.py b/forms.py
index 5085c89..22681da 100644
--- a/forms.py
+++ b/forms.py
@@ -33,18 +33,5 @@ class StudentForm(FlaskForm):
         super(StudentForm, self).__init__(*args, **kwargs)
         self.class_group_id.choices = [(cg.id, cg.name) for cg in ClassGroup.query.order_by(ClassGroup.name).all()]
 
-class ExerciseForm(FlaskForm):
-    title = StringField('Titre', validators=[DataRequired(), Length(max=200)])
-    description = TextAreaField('Description', validators=[Optional()])
-    order = IntegerField('Ordre', validators=[DataRequired(), NumberRange(min=1)], default=1)
-    submit = SubmitField('Enregistrer')
-
-class GradingElementForm(FlaskForm):
-    label = StringField('Libellé', validators=[DataRequired(), Length(max=200)])
-    description = TextAreaField('Description', validators=[Optional()])
-    skill = StringField('Compétence', validators=[Optional(), Length(max=200)])
-    max_points = FloatField('Barème (points max)', validators=[DataRequired(), NumberRange(min=0.1)], default=1.0)
-    grading_type = SelectField('Type de notation', validators=[DataRequired()], 
-                              choices=[('points', 'Points (ex: 2.5/4)'), ('score', 'Score (0, 1, 2, 3, .)')],
-                              default='points')
-    submit = SubmitField('Enregistrer')
\ No newline at end of file
+# Formulaires ExerciseForm et GradingElementForm supprimés
+# Ces éléments sont maintenant gérés via le formulaire unifié AssessmentForm
\ No newline at end of file
diff --git a/models.py b/models.py
index 7a029c5..9d53772 100644
--- a/models.py
+++ b/models.py
@@ -1,5 +1,7 @@
 from flask_sqlalchemy import SQLAlchemy
 from datetime import datetime
+from sqlalchemy import Index, CheckConstraint
+from decimal import Decimal
 
 db = SQLAlchemy()
 
@@ -10,6 +12,7 @@ class ClassGroup(db.Model):
     year = db.Column(db.String(20), nullable=False)
     students = db.relationship('Student', backref='class_group', lazy=True)
     assessments = db.relationship('Assessment', backref='class_group', lazy=True)
+    
 
     def __repr__(self):
         return f'<ClassGroup {self.name}>'
@@ -24,6 +27,10 @@ class Student(db.Model):
 
     def __repr__(self):
         return f'<Student {self.first_name} {self.last_name}>'
+    
+    @property
+    def full_name(self):
+        return f"{self.first_name} {self.last_name}"
 
 class Assessment(db.Model):
     id = db.Column(db.Integer, primary_key=True)
@@ -31,7 +38,7 @@ class Assessment(db.Model):
     description = db.Column(db.Text)
     date = db.Column(db.Date, nullable=False, default=datetime.utcnow)
     class_group_id = db.Column(db.Integer, db.ForeignKey('class_group.id'), nullable=False)
-    coefficient = db.Column(db.Float, default=1.0)
+    coefficient = db.Column(db.Float, default=1.0)  # Garder Float pour compatibilité
     exercises = db.relationship('Exercise', backref='assessment', lazy=True, cascade='all, delete-orphan')
 
     def __repr__(self):
@@ -54,8 +61,8 @@ class GradingElement(db.Model):
     label = db.Column(db.String(200), nullable=False)
     description = db.Column(db.Text)
     skill = db.Column(db.String(200))
-    max_points = db.Column(db.Float, nullable=False)
-    grading_type = db.Column(db.String(10), nullable=False, default='points')  # 'score' or 'points'
+    max_points = db.Column(db.Float, nullable=False)  # Garder Float pour compatibilité
+    grading_type = db.Column(db.String(10), nullable=False, default='points')
     grades = db.relationship('Grade', backref='grading_element', lazy=True, cascade='all, delete-orphan')
 
     def __repr__(self):
@@ -65,8 +72,9 @@ class Grade(db.Model):
     id = db.Column(db.Integer, primary_key=True)
     student_id = db.Column(db.Integer, db.ForeignKey('student.id'), nullable=False)
     grading_element_id = db.Column(db.Integer, db.ForeignKey('grading_element.id'), nullable=False)
-    value = db.Column(db.String(10))  # String to handle scores (0,1,2,3,.) and points
+    value = db.Column(db.String(10))  # Garder l'ancien format pour compatibilité
     comment = db.Column(db.Text)
+    
 
     def __repr__(self):
-        return f'<Grade {self.value} for {self.student.first_name}>'
\ No newline at end of file
+        return f'<Grade {self.value} for {self.student.first_name if self.student else "Unknown"}>'
\ No newline at end of file
diff --git a/routes/assessments.py b/routes/assessments.py
index 82e1105..77d6ef8 100644
--- a/routes/assessments.py
+++ b/routes/assessments.py
@@ -1,55 +1,153 @@
-from flask import Blueprint, render_template, redirect, url_for, flash, request
+from flask import Blueprint, render_template, redirect, url_for, flash, request, jsonify, current_app
 from models import db, Assessment, ClassGroup
 from forms import AssessmentForm
+from services import AssessmentService
+from utils import handle_db_errors, ValidationError
+from datetime import datetime
 
 bp = Blueprint('assessments', __name__, url_prefix='/assessments')
 
 @bp.route('/')
+@handle_db_errors
 def list():
-    assessments = Assessment.query.join(ClassGroup).order_by(Assessment.date.desc()).all()
+    from sqlalchemy.orm import joinedload
+    assessments = Assessment.query.options(joinedload(Assessment.class_group)).order_by(Assessment.date.desc()).all()
     return render_template('assessments.html', assessments=assessments)
 
-@bp.route('/new', methods=['GET', 'POST'])
-def new():
-    form = AssessmentForm()
-    if form.validate_on_submit():
-        assessment = Assessment(
-            title=form.title.data,
-            description=form.description.data,
-            date=form.date.data,
-            class_group_id=form.class_group_id.data,
-            coefficient=form.coefficient.data
-        )
-        db.session.add(assessment)
-        db.session.commit()
-        flash('Évaluation créée avec succès !', 'success')
-        return redirect(url_for('assessments.detail', id=assessment.id))
-    return render_template('assessment_form.html', form=form, title='Nouvelle évaluation')
+# Route obsolète supprimée - utiliser new_unified à la place
 
 @bp.route('/<int:id>')
+@handle_db_errors
 def detail(id):
-    assessment = Assessment.query.get_or_404(id)
+    from sqlalchemy.orm import joinedload
+    from models import Exercise, GradingElement
+    assessment = Assessment.query.options(
+        joinedload(Assessment.class_group),
+        joinedload(Assessment.exercises).joinedload(Exercise.grading_elements)
+    ).get_or_404(id)
     return render_template('assessment_detail.html', assessment=assessment)
 
+def _handle_unified_assessment_request(form, assessment=None, is_edit=False):
+    """Fonction helper pour traiter les requêtes JSON d'évaluation unifiée"""
+    # Ne traiter que les requêtes POST
+    if request.method != 'POST':
+        return None
+        
+    if request.is_json:
+        try:
+            data = request.get_json()
+            if not data:
+                return jsonify({'success': False, 'error': 'Aucune donnée fournie'}), 400
+            
+            # Peupler le formulaire pour validation CSRF
+            form.csrf_token.data = data.get('csrf_token')
+            
+            # Traitement via le service
+            if is_edit and assessment:
+                processed_assessment = AssessmentService.process_assessment_with_exercises(
+                    data, is_edit=True, existing_assessment=assessment
+                )
+            else:
+                processed_assessment = AssessmentService.process_assessment_with_exercises(data)
+            
+            db.session.commit()
+            flash('Évaluation ' + ('modifiée' if is_edit else 'créée') + ' avec succès !', 'success')
+            return jsonify({'success': True, 'assessment_id': processed_assessment.id})
+            
+        except ValidationError as e:
+            current_app.logger.warning(f'Erreur de validation: {e}')
+            return jsonify({'success': False, 'error': str(e)}), 400
+        except ValueError as e:
+            current_app.logger.warning(f'Erreur de données: {e}')
+            return jsonify({'success': False, 'error': str(e)}), 400
+            
+    else:  # request.method == 'POST' and not request.is_json
+        # Traitement classique du formulaire (fallback)
+        if form.validate_on_submit():
+            if is_edit and assessment:
+                AssessmentService.update_assessment_basic_info(assessment, {
+                    'title': form.title.data,
+                    'description': form.description.data,
+                    'date': form.date.data,
+                    'class_group_id': form.class_group_id.data,
+                    'coefficient': form.coefficient.data
+                })
+            else:
+                assessment = AssessmentService.create_assessment({
+                    'title': form.title.data,
+                    'description': form.description.data,
+                    'date': form.date.data,
+                    'class_group_id': form.class_group_id.data,
+                    'coefficient': form.coefficient.data
+                })
+            db.session.commit()
+            flash('Évaluation ' + ('modifiée' if is_edit else 'créée') + ' avec succès !', 'success')
+            return redirect(url_for('assessments.detail', id=assessment.id))
+    
+    return None
+
 @bp.route('/<int:id>/edit', methods=['GET', 'POST'])
+@handle_db_errors
 def edit(id):
-    assessment = Assessment.query.get_or_404(id)
+    from sqlalchemy.orm import joinedload
+    from models import Exercise, GradingElement
+    assessment = Assessment.query.options(
+        joinedload(Assessment.class_group),
+        joinedload(Assessment.exercises).joinedload(Exercise.grading_elements)
+    ).get_or_404(id)
     form = AssessmentForm(obj=assessment)
-    if form.validate_on_submit():
-        assessment.title = form.title.data
-        assessment.description = form.description.data
-        assessment.date = form.date.data
-        assessment.class_group_id = form.class_group_id.data
-        assessment.coefficient = form.coefficient.data
-        db.session.commit()
-        flash('Évaluation modifiée avec succès !', 'success')
-        return redirect(url_for('assessments.detail', id=assessment.id))
-    return render_template('assessment_form.html', form=form, title='Modifier l\'évaluation', assessment=assessment)
+    
+    result = _handle_unified_assessment_request(form, assessment, is_edit=True)
+    if result:
+        return result
+    
+    # Préparer les exercices pour la sérialisation JSON
+    exercises_data = []
+    for exercise in assessment.exercises:
+        exercise_data = {
+            'id': exercise.id,
+            'title': exercise.title,
+            'description': exercise.description or '',
+            'order': exercise.order,
+            'grading_elements': []
+        }
+        for element in exercise.grading_elements:
+            element_data = {
+                'id': element.id,
+                'label': element.label,
+                'description': element.description or '',
+                'skill': element.skill or '',
+                'max_points': float(element.max_points),
+                'grading_type': element.grading_type
+            }
+            exercise_data['grading_elements'].append(element_data)
+        exercises_data.append(exercise_data)
+    
+    return render_template('assessment_form_unified.html', 
+                         form=form, 
+                         title='Modifier l\'évaluation complète', 
+                         assessment=assessment, 
+                         exercises_json=exercises_data,
+                         is_edit=True)
+
+@bp.route('/new', methods=['GET', 'POST'])
+@handle_db_errors
+def new():
+    form = AssessmentForm()
+    
+    result = _handle_unified_assessment_request(form, is_edit=False)
+    if result:
+        return result
+    
+    return render_template('assessment_form_unified.html', form=form, title='Nouvelle évaluation complète')
 
 @bp.route('/<int:id>/delete', methods=['POST'])
+@handle_db_errors
 def delete(id):
     assessment = Assessment.query.get_or_404(id)
+    title = assessment.title  # Conserver pour le log
     db.session.delete(assessment)
     db.session.commit()
+    current_app.logger.info(f'Évaluation supprimée: {title} (ID: {id})')
     flash('Évaluation supprimée avec succès !', 'success')
     return redirect(url_for('assessments.list'))
\ No newline at end of file
diff --git a/routes/exercises.py b/routes/exercises.py
index c1b9cde..5ba002c 100644
--- a/routes/exercises.py
+++ b/routes/exercises.py
@@ -1,113 +1,17 @@
-from flask import Blueprint, render_template, redirect, url_for, flash, request
-from models import db, Assessment, Exercise, GradingElement
-from forms import ExerciseForm, GradingElementForm
+from flask import Blueprint, render_template
+from models import Assessment, Exercise
+from utils import handle_db_errors
 
 bp = Blueprint('exercises', __name__)
 
-# Exercise routes
-@bp.route('/assessments/<int:assessment_id>/exercises/new', methods=['GET', 'POST'])
-def new(assessment_id):
-    assessment = Assessment.query.get_or_404(assessment_id)
-    form = ExerciseForm()
-    
-    # Set default order to next available
-    if form.order.data == 1:  # Only if it's the default value
-        max_order = db.session.query(db.func.max(Exercise.order)).filter_by(assessment_id=assessment_id).scalar()
-        form.order.data = (max_order or 0) + 1
-    
-    if form.validate_on_submit():
-        exercise = Exercise(
-            assessment_id=assessment_id,
-            title=form.title.data,
-            description=form.description.data,
-            order=form.order.data
-        )
-        db.session.add(exercise)
-        db.session.commit()
-        flash('Exercice créé avec succès !', 'success')
-        return redirect(url_for('exercises.detail', assessment_id=assessment_id, id=exercise.id))
-    
-    return render_template('exercise_form.html', form=form, assessment=assessment, title='Nouvel exercice')
+# Routes de consultation seulement - La création/modification se fait via le formulaire unifié d'évaluation
 
 @bp.route('/assessments/<int:assessment_id>/exercises/<int:id>')
+@handle_db_errors  
 def detail(assessment_id, id):
+    from sqlalchemy.orm import joinedload
     assessment = Assessment.query.get_or_404(assessment_id)
-    exercise = Exercise.query.filter_by(id=id, assessment_id=assessment_id).first_or_404()
-    return render_template('exercise_detail.html', assessment=assessment, exercise=exercise)
-
-@bp.route('/assessments/<int:assessment_id>/exercises/<int:id>/edit', methods=['GET', 'POST'])
-def edit(assessment_id, id):
-    assessment = Assessment.query.get_or_404(assessment_id)
-    exercise = Exercise.query.filter_by(id=id, assessment_id=assessment_id).first_or_404()
-    form = ExerciseForm(obj=exercise)
-    
-    if form.validate_on_submit():
-        exercise.title = form.title.data
-        exercise.description = form.description.data
-        exercise.order = form.order.data
-        db.session.commit()
-        flash('Exercice modifié avec succès !', 'success')
-        return redirect(url_for('exercises.detail', assessment_id=assessment_id, id=exercise.id))
-    
-    return render_template('exercise_form.html', form=form, assessment=assessment, exercise=exercise, title='Modifier l\'exercice')
-
-@bp.route('/assessments/<int:assessment_id>/exercises/<int:id>/delete', methods=['POST'])
-def delete(assessment_id, id):
-    assessment = Assessment.query.get_or_404(assessment_id)
-    exercise = Exercise.query.filter_by(id=id, assessment_id=assessment_id).first_or_404()
-    db.session.delete(exercise)
-    db.session.commit()
-    flash('Exercice supprimé avec succès !', 'success')
-    return redirect(url_for('assessments.detail', id=assessment_id))
-
-# GradingElement routes
-@bp.route('/assessments/<int:assessment_id>/exercises/<int:exercise_id>/elements/new', methods=['GET', 'POST'])
-def new_grading_element(assessment_id, exercise_id):
-    assessment = Assessment.query.get_or_404(assessment_id)
-    exercise = Exercise.query.filter_by(id=exercise_id, assessment_id=assessment_id).first_or_404()
-    form = GradingElementForm()
-    
-    if form.validate_on_submit():
-        element = GradingElement(
-            exercise_id=exercise_id,
-            label=form.label.data,
-            description=form.description.data,
-            skill=form.skill.data,
-            max_points=form.max_points.data,
-            grading_type=form.grading_type.data
-        )
-        db.session.add(element)
-        db.session.commit()
-        flash('Élément de notation créé avec succès !', 'success')
-        return redirect(url_for('exercises.detail', assessment_id=assessment_id, id=exercise_id))
-    
-    return render_template('grading_element_form.html', form=form, assessment=assessment, exercise=exercise, title='Nouvel élément de notation')
-
-@bp.route('/assessments/<int:assessment_id>/exercises/<int:exercise_id>/elements/<int:id>/edit', methods=['GET', 'POST'])
-def edit_grading_element(assessment_id, exercise_id, id):
-    assessment = Assessment.query.get_or_404(assessment_id)
-    exercise = Exercise.query.filter_by(id=exercise_id, assessment_id=assessment_id).first_or_404()
-    element = GradingElement.query.filter_by(id=id, exercise_id=exercise_id).first_or_404()
-    form = GradingElementForm(obj=element)
-    
-    if form.validate_on_submit():
-        element.label = form.label.data
-        element.description = form.description.data
-        element.skill = form.skill.data
-        element.max_points = form.max_points.data
-        element.grading_type = form.grading_type.data
-        db.session.commit()
-        flash('Élément de notation modifié avec succès !', 'success')
-        return redirect(url_for('exercises.detail', assessment_id=assessment_id, id=exercise_id))
-    
-    return render_template('grading_element_form.html', form=form, assessment=assessment, exercise=exercise, element=element, title='Modifier l\'élément de notation')
-
-@bp.route('/assessments/<int:assessment_id>/exercises/<int:exercise_id>/elements/<int:id>/delete', methods=['POST'])
-def delete_grading_element(assessment_id, exercise_id, id):
-    assessment = Assessment.query.get_or_404(assessment_id)
-    exercise = Exercise.query.filter_by(id=exercise_id, assessment_id=assessment_id).first_or_404()
-    element = GradingElement.query.filter_by(id=id, exercise_id=exercise_id).first_or_404()
-    db.session.delete(element)
-    db.session.commit()
-    flash('Élément de notation supprimé avec succès !', 'success')
-    return redirect(url_for('exercises.detail', assessment_id=assessment_id, id=exercise_id))
\ No newline at end of file
+    exercise = Exercise.query.options(
+        joinedload(Exercise.grading_elements)
+    ).filter_by(id=id, assessment_id=assessment_id).first_or_404()
+    return render_template('exercise_detail.html', assessment=assessment, exercise=exercise)
\ No newline at end of file
diff --git a/services.py b/services.py
new file mode 100644
index 0000000..441ad0a
--- /dev/null
+++ b/services.py
@@ -0,0 +1,140 @@
+from models import db, Assessment, Exercise, GradingElement
+from utils import safe_int_conversion, safe_decimal_conversion, validate_json_data, ValidationError, log_user_action
+from datetime import datetime
+from decimal import Decimal
+
+class AssessmentService:
+    """Service pour gérer les opérations sur les évaluations"""
+    
+    @staticmethod
+    def create_assessment(form_data):
+        """Crée une nouvelle évaluation"""
+        assessment = Assessment(
+            title=form_data['title'],
+            description=form_data.get('description', ''),
+            date=form_data['date'],
+            class_group_id=form_data['class_group_id'],
+            coefficient=form_data['coefficient']
+        )
+        db.session.add(assessment)
+        db.session.flush()  # Pour obtenir l'ID
+        log_user_action("Création évaluation", f"ID: {assessment.id}, Titre: {assessment.title}")
+        return assessment
+    
+    @staticmethod
+    def update_assessment_basic_info(assessment, form_data):
+        """Met à jour les informations de base d'une évaluation"""
+        assessment.title = form_data['title']
+        assessment.description = form_data.get('description', '')
+        assessment.date = form_data['date']
+        assessment.class_group_id = form_data['class_group_id']
+        assessment.coefficient = form_data['coefficient']
+        log_user_action("Modification évaluation", f"ID: {assessment.id}")
+    
+    @staticmethod
+    def delete_assessment_exercises(assessment):
+        """Supprime tous les exercices d'une évaluation (pour remplacement)"""
+        for exercise in assessment.exercises:
+            db.session.delete(exercise)
+    
+    @staticmethod
+    def process_assessment_with_exercises(assessment_data, is_edit=False, existing_assessment=None):
+        """Traite une évaluation complète avec exercices et éléments"""
+        # Validation des données de base
+        required_fields = ['title', 'date', 'class_group_id', 'coefficient']
+        validate_json_data(assessment_data, required_fields)
+        
+        # Validation et conversion des types
+        try:
+            class_group_id = safe_int_conversion(assessment_data['class_group_id'], "ID de classe")
+            coefficient = safe_decimal_conversion(assessment_data['coefficient'], "coefficient")
+            
+            # Validation de la date
+            date_str = assessment_data.get('date')
+            if date_str:
+                date_obj = datetime.strptime(date_str, '%Y-%m-%d').date()
+            else:
+                raise ValidationError("Date requise")
+                
+        except ValueError as e:
+            raise ValidationError(str(e))
+        
+        # Préparation des données validées
+        validated_data = {
+            'title': assessment_data['title'].strip(),
+            'description': assessment_data.get('description', '').strip(),
+            'date': date_obj,
+            'class_group_id': class_group_id,
+            'coefficient': coefficient
+        }
+        
+        # Création ou mise à jour de l'évaluation
+        if is_edit and existing_assessment:
+            AssessmentService.update_assessment_basic_info(existing_assessment, validated_data)
+            AssessmentService.delete_assessment_exercises(existing_assessment)
+            assessment = existing_assessment
+        else:
+            assessment = AssessmentService.create_assessment(validated_data)
+        
+        # Traitement des exercices
+        exercises_data = assessment_data.get('exercises', [])
+        AssessmentService.process_exercises(assessment, exercises_data)
+        
+        return assessment
+    
+    @staticmethod
+    def process_exercises(assessment, exercises_data):
+        """Traite les exercices d'une évaluation"""
+        for ex_data in exercises_data:
+            # Validation des données d'exercice
+            if not ex_data.get('title'):
+                raise ValidationError("Titre d'exercice requis")
+            
+            try:
+                order = safe_int_conversion(ex_data.get('order', 1), "ordre de l'exercice")
+                if order < 1:
+                    raise ValidationError("L'ordre de l'exercice doit être positif")
+            except ValueError as e:
+                raise ValidationError(str(e))
+            
+            exercise = Exercise(
+                title=ex_data['title'].strip(),
+                description=ex_data.get('description', '').strip(),
+                order=order,
+                assessment_id=assessment.id
+            )
+            db.session.add(exercise)
+            db.session.flush()
+            
+            # Traitement des éléments de notation
+            grading_elements_data = ex_data.get('grading_elements', [])
+            AssessmentService.process_grading_elements(exercise, grading_elements_data)
+    
+    @staticmethod
+    def process_grading_elements(exercise, grading_elements_data):
+        """Traite les éléments de notation d'un exercice"""
+        for elem_data in grading_elements_data:
+            # Validation des données d'élément
+            if not elem_data.get('label'):
+                raise ValidationError("Libellé d'élément de notation requis")
+            
+            grading_type = elem_data.get('grading_type', 'points')
+            if grading_type not in ['points', 'score']:
+                raise ValidationError("Type de notation invalide")
+            
+            try:
+                max_points = safe_decimal_conversion(elem_data.get('max_points'), "points maximum")
+                if max_points <= 0:
+                    raise ValidationError("Les points maximum doivent être positifs")
+            except ValueError as e:
+                raise ValidationError(str(e))
+            
+            grading_element = GradingElement(
+                label=elem_data['label'].strip(),
+                description=elem_data.get('description', '').strip(),
+                skill=elem_data.get('skill', '').strip(),
+                max_points=max_points,
+                grading_type=grading_type,
+                exercise_id=exercise.id
+            )
+            db.session.add(grading_element)
\ No newline at end of file
diff --git a/static/css/app.css b/static/css/app.css
new file mode 100644
index 0000000..2b3c912
--- /dev/null
+++ b/static/css/app.css
@@ -0,0 +1,140 @@
+/* Styles personnalisés pour l'application */
+
+/* Focus visible amélioré pour l'accessibilité */
+*:focus {
+    outline: 2px solid #3b82f6;
+    outline-offset: 2px;
+}
+
+/* Amélioration du contraste pour les textes */
+.text-gray-600 {
+    color: #4b5563;
+}
+
+.text-gray-700 {
+    color: #374151;
+}
+
+/* Transitions fluides */
+.transition-colors {
+    transition-property: color, background-color, border-color;
+    transition-timing-function: cubic-bezier(0.4, 0, 0.2, 1);
+    transition-duration: 150ms;
+}
+
+/* Skip link pour l'accessibilité */
+.skip-link {
+    position: absolute;
+    top: -40px;
+    left: 6px;
+    background: #000;
+    color: #fff;
+    padding: 8px;
+    text-decoration: none;
+    z-index: 1000;
+}
+
+.skip-link:focus {
+    top: 6px;
+}
+
+/* Améliorations pour les formulaires */
+input:invalid,
+select:invalid,
+textarea:invalid {
+    border-color: #ef4444;
+    box-shadow: 0 0 0 1px #ef4444;
+}
+
+input:valid,
+select:valid,
+textarea:valid {
+    border-color: #10b981;
+}
+
+/* Amélioration des messages d'erreur */
+.error-message {
+    display: flex;
+    align-items: center;
+    margin-top: 0.25rem;
+    font-size: 0.875rem;
+    color: #dc2626;
+}
+
+.error-message::before {
+    content: "⚠";
+    margin-right: 0.25rem;
+}
+
+/* Styles pour les boutons avec meilleur contraste */
+.btn-primary {
+    background-color: #2563eb;
+    color: white;
+    padding: 0.5rem 1rem;
+    border-radius: 0.375rem;
+    border: 2px solid #2563eb;
+    transition: all 0.15s ease-in-out;
+}
+
+.btn-primary:hover {
+    background-color: #1d4ed8;
+    border-color: #1d4ed8;
+}
+
+.btn-primary:focus {
+    outline: 2px solid #3b82f6;
+    outline-offset: 2px;
+}
+
+.btn-secondary {
+    background-color: #f9fafb;
+    color: #374151;
+    padding: 0.5rem 1rem;
+    border-radius: 0.375rem;
+    border: 2px solid #d1d5db;
+    transition: all 0.15s ease-in-out;
+}
+
+.btn-secondary:hover {
+    background-color: #f3f4f6;
+    border-color: #9ca3af;
+}
+
+/* Tables responsive */
+.table-responsive {
+    overflow-x: auto;
+}
+
+@media (max-width: 768px) {
+    .table-responsive table {
+        font-size: 0.875rem;
+    }
+}
+
+/* Animation pour les messages flash */
+@keyframes fadeIn {
+    from { opacity: 0; transform: translateY(-10px); }
+    to { opacity: 1; transform: translateY(0); }
+}
+
+.flash-message {
+    animation: fadeIn 0.3s ease-out;
+}
+
+/* Améliorations pour mobile */
+@media (max-width: 640px) {
+    .mobile-menu-button {
+        display: block;
+    }
+    
+    .desktop-menu {
+        display: none;
+    }
+}
+
+/* High contrast mode support */
+@media (prefers-contrast: high) {
+    .bg-gray-100 { background-color: #ffffff; }
+    .text-gray-600 { color: #000000; }
+    .border-gray-300 { border-color: #000000; }
+}
\ No newline at end of file
diff --git a/templates/assessment_detail.html b/templates/assessment_detail.html
index 9a5b7cb..5d154a3 100644
--- a/templates/assessment_detail.html
+++ b/templates/assessment_detail.html
@@ -13,8 +13,8 @@
             <p class="text-gray-600">{{ assessment.class_group.name }} - {{ assessment.date.strftime('%d/%m/%Y') }}</p>
         </div>
         <div class="flex space-x-3">
-            <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="bg-gray-600 hover:bg-gray-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
-                Modifier
+            <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
+                Modifier l'évaluation complète
             </a>
             <button onclick="if(confirm('Êtes-vous sûr de vouloir supprimer cette évaluation ?')) { document.getElementById('delete-form').submit(); }" 
                     class="bg-red-600 hover:bg-red-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
@@ -62,9 +62,9 @@
     <div class="bg-white shadow rounded-lg">
         <div class="px-6 py-4 border-b border-gray-200 flex justify-between items-center">
             <h2 class="text-lg font-medium text-gray-900">Exercices</h2>
-            <a href="{{ url_for('exercises.new', assessment_id=assessment.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
-                Ajouter un exercice
-            </a>
+            <span class="text-sm text-gray-500">
+                Utilisez "Modifier l'évaluation complète" pour ajouter des exercices
+            </span>
         </div>
         <div class="px-6 py-4">
             {% if assessment.exercises %}
@@ -85,9 +85,6 @@
                                     <a href="{{ url_for('exercises.detail', assessment_id=assessment.id, id=exercise.id) }}" class="text-blue-600 hover:text-blue-800 text-sm font-medium">
                                         Voir détails
                                     </a>
-                                    <a href="{{ url_for('exercises.edit', assessment_id=assessment.id, id=exercise.id) }}" class="text-gray-600 hover:text-gray-800 text-sm font-medium">
-                                        Modifier
-                                    </a>
                                 </div>
                             </div>
                         </div>
@@ -101,8 +98,8 @@
                     <h3 class="mt-2 text-sm font-medium text-gray-900">Aucun exercice</h3>
                     <p class="mt-1 text-sm text-gray-500">Commencez par ajouter le premier exercice de cette évaluation.</p>
                     <div class="mt-6">
-                        <a href="{{ url_for('exercises.new', assessment_id=assessment.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
-                            Ajouter un exercice
+                        <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
+                            Modifier l'évaluation complète
                         </a>
                     </div>
                 </div>
diff --git a/templates/assessment_form.html b/templates/assessment_form.html
deleted file mode 100644
index 00117cf..0000000
--- a/templates/assessment_form.html
+++ /dev/null
@@ -1,102 +0,0 @@
-{% extends "base.html" %}
-
-{% block title %}{{ title }} - Gestion Scolaire{% endblock %}
-
-{% block content %}
-<div class="max-w-2xl mx-auto">
-    <div class="mb-6">
-        <a href="{{ url_for('assessments.list') }}" class="text-blue-600 hover:text-blue-800 text-sm font-medium">
-            ← Retour aux évaluations
-        </a>
-    </div>
-    
-    <div class="bg-white shadow rounded-lg">
-        <div class="px-6 py-4 border-b border-gray-200">
-            <h1 class="text-xl font-semibold text-gray-900">{{ title }}</h1>
-        </div>
-        
-        <form method="POST" class="px-6 py-4 space-y-6">
-            {{ form.hidden_tag() }}
-            
-            <div>
-                <label for="{{ form.title.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.title.label.text }}
-                </label>
-                {{ form.title(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                {% if form.title.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.title.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-            </div>
-            
-            <div>
-                <label for="{{ form.description.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.description.label.text }}
-                </label>
-                {{ form.description(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500", rows="3") }}
-                {% if form.description.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.description.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-            </div>
-            
-            <div class="grid grid-cols-1 md:grid-cols-2 gap-6">
-                <div>
-                    <label for="{{ form.date.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                        {{ form.date.label.text }}
-                    </label>
-                    {{ form.date(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                    {% if form.date.errors %}
-                        <div class="mt-1 text-sm text-red-600">
-                            {% for error in form.date.errors %}
-                                <p>{{ error }}</p>
-                            {% endfor %}
-                        </div>
-                    {% endif %}
-                </div>
-                
-                <div>
-                    <label for="{{ form.coefficient.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                        {{ form.coefficient.label.text }}
-                    </label>
-                    {{ form.coefficient(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500", step="0.1") }}
-                    {% if form.coefficient.errors %}
-                        <div class="mt-1 text-sm text-red-600">
-                            {% for error in form.coefficient.errors %}
-                                <p>{{ error }}</p>
-                            {% endfor %}
-                        </div>
-                    {% endif %}
-                </div>
-            </div>
-            
-            <div>
-                <label for="{{ form.class_group_id.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.class_group_id.label.text }}
-                </label>
-                {{ form.class_group_id(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                {% if form.class_group_id.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.class_group_id.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-            </div>
-            
-            <div class="flex justify-end space-x-3 pt-4 border-t border-gray-200">
-                <a href="{{ url_for('assessments.list') }}" class="px-4 py-2 border border-gray-300 rounded-md text-sm font-medium text-gray-700 hover:bg-gray-50 transition-colors">
-                    Annuler
-                </a>
-                {{ form.submit(class="px-4 py-2 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700 transition-colors") }}
-            </div>
-        </form>
-    </div>
-</div>
-{% endblock %}
\ No newline at end of file
diff --git a/templates/assessment_form_unified.html b/templates/assessment_form_unified.html
new file mode 100644
index 0000000..409d09b
--- /dev/null
+++ b/templates/assessment_form_unified.html
@@ -0,0 +1,532 @@
+{% extends "base.html" %}
+
+{% block title %}{{ title }} - Gestion Scolaire{% endblock %}
+
+{% block content %}
+<div class="max-w-6xl mx-auto">
+    <div class="mb-6">
+        {% if is_edit %}
+            <a href="{{ url_for('assessments.detail', id=assessment.id) }}" class="text-blue-600 hover:text-blue-800 text-sm font-medium">
+                ← Retour à l'évaluation
+            </a>
+        {% else %}
+            <a href="{{ url_for('assessments.list') }}" class="text-blue-600 hover:text-blue-800 text-sm font-medium">
+                ← Retour aux évaluations
+            </a>
+        {% endif %}
+    </div>
+    
+    <div class="bg-white shadow rounded-lg">
+        <div class="px-6 py-4 border-b border-gray-200">
+            <h1 class="text-xl font-semibold text-gray-900">{{ title }}</h1>
+            {% if is_edit %}
+                <p class="text-sm text-gray-600 mt-1">Modifiez votre évaluation complète avec exercices et éléments de notation</p>
+            {% else %}
+                <p class="text-sm text-gray-600 mt-1">Créez votre évaluation complète avec exercices et éléments de notation</p>
+            {% endif %}
+        </div>
+        
+        <form id="unified-form" method="POST" class="px-6 py-6 space-y-8">
+            {{ form.hidden_tag() }}
+            
+            <!-- Section Évaluation -->
+            <div class="bg-blue-50 border border-blue-200 rounded-lg p-6">
+                <h2 class="text-lg font-medium text-blue-900 mb-4">📝 Informations de l'évaluation</h2>
+                
+                <div class="grid grid-cols-1 md:grid-cols-2 gap-6">
+                    <div>
+                        <label for="{{ form.title.id }}" class="block text-sm font-medium text-gray-700 mb-1">
+                            {{ form.title.label.text }}
+                        </label>
+                        {{ form.title(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
+                        {% if form.title.errors %}
+                            <div class="mt-1 text-sm text-red-600">
+                                {% for error in form.title.errors %}
+                                    <p>{{ error }}</p>
+                                {% endfor %}
+                            </div>
+                        {% endif %}
+                    </div>
+                    
+                    <div>
+                        <label for="{{ form.class_group_id.id }}" class="block text-sm font-medium text-gray-700 mb-1">
+                            {{ form.class_group_id.label.text }}
+                        </label>
+                        {{ form.class_group_id(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
+                        {% if form.class_group_id.errors %}
+                            <div class="mt-1 text-sm text-red-600">
+                                {% for error in form.class_group_id.errors %}
+                                    <p>{{ error }}</p>
+                                {% endfor %}
+                            </div>
+                        {% endif %}
+                    </div>
+                    
+                    <div>
+                        <label for="{{ form.date.id }}" class="block text-sm font-medium text-gray-700 mb-1">
+                            {{ form.date.label.text }}
+                        </label>
+                        {{ form.date(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
+                        {% if form.date.errors %}
+                            <div class="mt-1 text-sm text-red-600">
+                                {% for error in form.date.errors %}
+                                    <p>{{ error }}</p>
+                                {% endfor %}
+                            </div>
+                        {% endif %}
+                    </div>
+                    
+                    <div>
+                        <label for="{{ form.coefficient.id }}" class="block text-sm font-medium text-gray-700 mb-1">
+                            {{ form.coefficient.label.text }}
+                        </label>
+                        {{ form.coefficient(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500", step="0.5") }}
+                        {% if form.coefficient.errors %}
+                            <div class="mt-1 text-sm text-red-600">
+                                {% for error in form.coefficient.errors %}
+                                    <p>{{ error }}</p>
+                                {% endfor %}
+                            </div>
+                        {% endif %}
+                    </div>
+                </div>
+                
+                <div class="mt-4">
+                    <label for="{{ form.description.id }}" class="block text-sm font-medium text-gray-700 mb-1">
+                        {{ form.description.label.text }}
+                    </label>
+                    {{ form.description(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500", rows="3") }}
+                    {% if form.description.errors %}
+                        <div class="mt-1 text-sm text-red-600">
+                            {% for error in form.description.errors %}
+                                <p>{{ error }}</p>
+                            {% endfor %}
+                        </div>
+                    {% endif %}
+                </div>
+            </div>
+            
+            <!-- Section Exercices -->
+            <div class="bg-green-50 border border-green-200 rounded-lg p-6">
+                <div class="mb-4">
+                    <h2 class="text-lg font-medium text-green-900">🏃 Exercices</h2>
+                </div>
+                
+                <div id="exercises-container" class="space-y-4">
+                    <!-- Les exercices seront ajoutés ici dynamiquement -->
+                </div>
+                
+                <div id="no-exercises" class="text-center py-8 text-green-700">
+                    <p class="text-sm">Aucun exercice ajouté. Utilisez le bouton ci-dessous pour commencer.</p>
+                </div>
+                
+                <!-- Bouton d'ajout placé après la liste pour une meilleure navigation clavier -->
+                <div class="mt-4 pt-4 border-t border-green-200">
+                    <button type="button" id="add-exercise" class="bg-green-600 hover:bg-green-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors focus:outline-none focus:ring-2 focus:ring-green-500 focus:ring-offset-2">
+                        ➕ Ajouter un exercice
+                    </button>
+                </div>
+            </div>
+            
+            <!-- Guide d'aide -->
+            <div class="bg-gray-50 border border-gray-200 rounded-lg p-4">
+                <h3 class="text-sm font-medium text-gray-900 mb-2">💡 Guide rapide</h3>
+                <div class="text-xs text-gray-700 space-y-1">
+                    <p><strong>Points :</strong> Notation classique (ex: 2.5/4 points)</p>
+                    <p><strong>Score :</strong> Évaluation par niveaux (0=non acquis, 1=en cours, 2=acquis, 3=expert, .=non évalué)</p>
+                    <p><strong>Ordre :</strong> Les exercices et éléments seront affichés dans l'ordre numérique</p>
+                </div>
+            </div>
+            
+            <!-- Actions -->
+            <div class="flex justify-end space-x-3 pt-4 border-t border-gray-200">
+                {% if is_edit %}
+                    <a href="{{ url_for('assessments.detail', id=assessment.id) }}" class="px-6 py-2 border border-gray-300 rounded-md text-sm font-medium text-gray-700 hover:bg-gray-50 transition-colors focus:outline-none focus:ring-2 focus:ring-gray-500 focus:ring-offset-2">
+                        Annuler
+                    </a>
+                    <button type="submit" class="px-6 py-2 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700 transition-colors focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2">
+                        💾 Modifier l'évaluation complète
+                    </button>
+                {% else %}
+                    <a href="{{ url_for('assessments.list') }}" class="px-6 py-2 border border-gray-300 rounded-md text-sm font-medium text-gray-700 hover:bg-gray-50 transition-colors focus:outline-none focus:ring-2 focus:ring-gray-500 focus:ring-offset-2">
+                        Annuler
+                    </a>
+                    <button type="submit" class="px-6 py-2 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700 transition-colors focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2">
+                        💾 Créer l'évaluation complète
+                    </button>
+                {% endif %}
+            </div>
+        </form>
+    </div>
+</div>
+
+<!-- Template pour un exercice -->
+<template id="exercise-template">
+    <div class="exercise-item border border-green-300 rounded-lg p-4 bg-white">
+        <div class="flex justify-between items-start mb-4">
+            <h3 class="text-md font-medium text-green-800">Exercice <span class="exercise-number"></span></h3>
+            <button type="button" class="remove-exercise text-red-600 hover:text-red-800 text-sm font-medium">
+                Supprimer
+            </button>
+        </div>
+        
+        <div class="grid grid-cols-1 md:grid-cols-2 gap-4 mb-4">
+            <div>
+                <label class="block text-sm font-medium text-gray-700 mb-1">Titre de l'exercice</label>
+                <input type="text" class="exercise-title block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-green-500 focus:border-green-500" required>
+            </div>
+            <div>
+                <label class="block text-sm font-medium text-gray-700 mb-1">Ordre</label>
+                <input type="number" class="exercise-order block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-green-500 focus:border-green-500" min="1" required>
+            </div>
+        </div>
+        
+        <div class="mb-4">
+            <label class="block text-sm font-medium text-gray-700 mb-1">Description (optionnel)</label>
+            <textarea class="exercise-description block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-green-500 focus:border-green-500" rows="2"></textarea>
+        </div>
+        
+        <!-- Éléments de notation -->
+        <div class="bg-purple-50 border border-purple-200 rounded p-4">
+            <div class="mb-3">
+                <h4 class="text-sm font-medium text-purple-900">Éléments de notation</h4>
+            </div>
+            
+            <div class="grading-elements-container space-y-3">
+                <!-- Les éléments de notation seront ajoutés ici -->
+            </div>
+            
+            <div class="no-grading-elements text-center py-4 text-purple-700 text-xs">
+                Aucun élément de notation. Utilisez le bouton ci-dessous pour commencer.
+            </div>
+            
+            <!-- Bouton d'ajout placé après la liste pour une meilleure navigation clavier -->
+            <div class="mt-3 pt-3 border-t border-purple-200">
+                <button type="button" class="add-grading-element bg-purple-600 hover:bg-purple-700 text-white px-3 py-1 rounded text-xs font-medium transition-colors focus:outline-none focus:ring-2 focus:ring-purple-500 focus:ring-offset-1">
+                    ➕ Ajouter élément
+                </button>
+            </div>
+        </div>
+    </div>
+</template>
+
+<!-- Template pour un élément de notation -->
+<template id="grading-element-template">
+    <div class="grading-element-item border border-purple-300 rounded p-3 bg-white">
+        <div class="flex justify-between items-start mb-3">
+            <h5 class="text-sm font-medium text-purple-800">Élément de notation</h5>
+            <button type="button" class="remove-grading-element text-red-600 hover:text-red-800 text-xs font-medium">
+                Supprimer
+            </button>
+        </div>
+        
+        <div class="grid grid-cols-1 md:grid-cols-2 gap-3">
+            <div>
+                <label class="block text-xs font-medium text-gray-700 mb-1">Label</label>
+                <input type="text" class="element-label block w-full border border-gray-300 rounded-md px-2 py-1 text-sm focus:ring-purple-500 focus:border-purple-500" required>
+            </div>
+            <div>
+                <label class="block text-xs font-medium text-gray-700 mb-1">Compétence</label>
+                <input type="text" class="element-skill block w-full border border-gray-300 rounded-md px-2 py-1 text-sm focus:ring-purple-500 focus:border-purple-500">
+            </div>
+            <div>
+                <label class="block text-xs font-medium text-gray-700 mb-1">Points max</label>
+                <input type="number" step="0.1" min="0" class="element-max-points block w-full border border-gray-300 rounded-md px-2 py-1 text-sm focus:ring-purple-500 focus:border-purple-500" required>
+            </div>
+            <div>
+                <label class="block text-xs font-medium text-gray-700 mb-1">Type de notation</label>
+                <select class="element-grading-type block w-full border border-gray-300 rounded-md px-2 py-1 text-sm focus:ring-purple-500 focus:border-purple-500" required>
+                    <option value="">Choisir...</option>
+                    <option value="points">Points</option>
+                    <option value="score">Score</option>
+                </select>
+            </div>
+        </div>
+        
+        <div class="mt-3">
+            <label class="block text-xs font-medium text-gray-700 mb-1">Description (optionnel)</label>
+            <textarea class="element-description block w-full border border-gray-300 rounded-md px-2 py-1 text-sm focus:ring-purple-500 focus:border-purple-500" rows="2"></textarea>
+        </div>
+    </div>
+</template>
+
+<script>
+let exerciseCounter = 0;
+
+document.addEventListener('DOMContentLoaded', function() {
+    const addExerciseBtn = document.getElementById('add-exercise');
+    const exercisesContainer = document.getElementById('exercises-container');
+    const noExercisesMsg = document.getElementById('no-exercises');
+    const form = document.getElementById('unified-form');
+    
+    // Pré-remplir les données en mode édition
+    {% if is_edit %}
+        loadExistingData();
+    {% endif %}
+    
+    // Ajouter un exercice
+    addExerciseBtn.addEventListener('click', function() {
+        addExercise();
+    });
+    
+    // Soumission du formulaire
+    form.addEventListener('submit', function(e) {
+        e.preventDefault();
+        submitForm();
+    });
+    
+    function addExercise() {
+        exerciseCounter++;
+        const template = document.getElementById('exercise-template');
+        const exerciseDiv = template.content.cloneNode(true);
+        
+        // Mettre à jour le numéro d'exercice
+        exerciseDiv.querySelector('.exercise-number').textContent = exerciseCounter;
+        exerciseDiv.querySelector('.exercise-order').value = exerciseCounter;
+        
+        // Ajouter les event listeners
+        const removeBtn = exerciseDiv.querySelector('.remove-exercise');
+        removeBtn.addEventListener('click', function() {
+            removeExercise(this);
+        });
+        
+        const addElementBtn = exerciseDiv.querySelector('.add-grading-element');
+        addElementBtn.addEventListener('click', function() {
+            addGradingElement(this);
+        });
+        
+        exercisesContainer.appendChild(exerciseDiv);
+        updateExercisesVisibility();
+        
+        // Focus automatique sur le champ titre du nouvel exercice pour faciliter la navigation clavier
+        setTimeout(() => {
+            const titleInput = exercisesContainer.lastElementChild.querySelector('.exercise-title');
+            if (titleInput) {
+                titleInput.focus();
+            }
+        }, 100);
+    }
+    
+    function removeExercise(btn) {
+        btn.closest('.exercise-item').remove();
+        updateExercisesVisibility();
+        renumberExercises();
+    }
+    
+    function addGradingElement(btn) {
+        const exerciseDiv = btn.closest('.exercise-item');
+        const elementsContainer = exerciseDiv.querySelector('.grading-elements-container');
+        const noElementsMsg = exerciseDiv.querySelector('.no-grading-elements');
+        
+        const template = document.getElementById('grading-element-template');
+        const elementDiv = template.content.cloneNode(true);
+        
+        // Ajouter l'event listener pour supprimer
+        const removeBtn = elementDiv.querySelector('.remove-grading-element');
+        removeBtn.addEventListener('click', function() {
+            removeGradingElement(this);
+        });
+        
+        elementsContainer.appendChild(elementDiv);
+        noElementsMsg.style.display = 'none';
+        
+        // Focus automatique sur le champ label du nouvel élément pour faciliter la navigation clavier
+        setTimeout(() => {
+            const labelInput = elementsContainer.lastElementChild.querySelector('.element-label');
+            if (labelInput) {
+                labelInput.focus();
+            }
+        }, 100);
+    }
+    
+    function removeGradingElement(btn) {
+        const exerciseDiv = btn.closest('.exercise-item');
+        const elementsContainer = exerciseDiv.querySelector('.grading-elements-container');
+        const noElementsMsg = exerciseDiv.querySelector('.no-grading-elements');
+        
+        btn.closest('.grading-element-item').remove();
+        
+        if (elementsContainer.children.length === 0) {
+            noElementsMsg.style.display = 'block';
+        }
+    }
+    
+    function updateExercisesVisibility() {
+        const hasExercises = exercisesContainer.children.length > 0;
+        noExercisesMsg.style.display = hasExercises ? 'none' : 'block';
+    }
+    
+    function renumberExercises() {
+        const exercises = exercisesContainer.querySelectorAll('.exercise-item');
+        exercises.forEach((exercise, index) => {
+            const number = index + 1;
+            exercise.querySelector('.exercise-number').textContent = number;
+            exercise.querySelector('.exercise-order').value = number;
+        });
+        exerciseCounter = exercises.length;
+    }
+    
+    function collectFormData() {
+        const exercises = [];
+        const exerciseItems = exercisesContainer.querySelectorAll('.exercise-item');
+        
+        exerciseItems.forEach(exerciseItem => {
+            const title = exerciseItem.querySelector('.exercise-title').value;
+            const description = exerciseItem.querySelector('.exercise-description').value;
+            const order = parseInt(exerciseItem.querySelector('.exercise-order').value);
+            
+            if (!title.trim()) return;
+            
+            const gradingElements = [];
+            const elementItems = exerciseItem.querySelectorAll('.grading-element-item');
+            
+            elementItems.forEach(elementItem => {
+                const label = elementItem.querySelector('.element-label').value;
+                const skill = elementItem.querySelector('.element-skill').value;
+                const maxPoints = parseFloat(elementItem.querySelector('.element-max-points').value);
+                const gradingType = elementItem.querySelector('.element-grading-type').value;
+                const description = elementItem.querySelector('.element-description').value;
+                
+                if (!label.trim() || !maxPoints || !gradingType) return;
+                
+                gradingElements.push({
+                    label: label.trim(),
+                    skill: skill.trim(),
+                    max_points: maxPoints,
+                    grading_type: gradingType,
+                    description: description.trim()
+                });
+            });
+            
+            exercises.push({
+                title: title.trim(),
+                description: description.trim(),
+                order: order,
+                grading_elements: gradingElements
+            });
+        });
+        
+        return exercises;
+    }
+    
+    function submitForm() {
+        const formData = new FormData(form);
+        const exercises = collectFormData();
+        
+        // Validation côté client
+        if (exercises.length === 0) {
+            alert('Vous devez ajouter au moins un exercice.');
+            return;
+        }
+        
+        let hasElementsWithoutGrading = false;
+        exercises.forEach(ex => {
+            if (ex.grading_elements.length === 0) {
+                hasElementsWithoutGrading = true;
+            }
+        });
+        
+        if (hasElementsWithoutGrading) {
+            if (!confirm('Certains exercices n\'ont pas d\'éléments de notation. Voulez-vous continuer ?')) {
+                return;
+            }
+        }
+        
+        // Envoyer via AJAX
+        const data = {
+            title: formData.get('title'),
+            description: formData.get('description'),
+            date: formData.get('date'),
+            class_group_id: formData.get('class_group_id'),
+            coefficient: formData.get('coefficient'),
+            exercises: exercises
+        };
+        
+        // Ajouter le CSRF token aux données
+        data.csrf_token = formData.get('csrf_token');
+        
+        fetch(form.action, {
+            method: 'POST',
+            headers: {
+                'Content-Type': 'application/json'
+            },
+            body: JSON.stringify(data)
+        })
+        .then(response => response.json())
+        .then(data => {
+            if (data.success) {
+                window.location.href = `/assessments/${data.assessment_id}`;
+            } else {
+                alert('Erreur lors de la création : ' + JSON.stringify(data.errors));
+            }
+        })
+        .catch(error => {
+            console.error('Erreur:', error);
+            alert('Une erreur est survenue lors de la création de l\'évaluation.');
+        });
+    }
+    
+    {% if is_edit %}
+    function loadExistingData() {
+        // Charger les exercices existants
+        const existingExercises = {{ exercises_json|tojson if exercises_json else "[]" }};
+        
+        existingExercises.forEach(exercise => {
+            exerciseCounter++;
+            const template = document.getElementById('exercise-template');
+            const exerciseDiv = template.content.cloneNode(true);
+            
+            // Remplir les données de l'exercice
+            exerciseDiv.querySelector('.exercise-number').textContent = exerciseCounter;
+            exerciseDiv.querySelector('.exercise-title').value = exercise.title;
+            exerciseDiv.querySelector('.exercise-description').value = exercise.description || '';
+            exerciseDiv.querySelector('.exercise-order').value = exercise.order;
+            
+            // Ajouter les event listeners
+            const removeBtn = exerciseDiv.querySelector('.remove-exercise');
+            removeBtn.addEventListener('click', function() {
+                removeExercise(this);
+            });
+            
+            const addElementBtn = exerciseDiv.querySelector('.add-grading-element');
+            addElementBtn.addEventListener('click', function() {
+                addGradingElement(this);
+            });
+            
+            const elementsContainer = exerciseDiv.querySelector('.grading-elements-container');
+            const noElementsMsg = exerciseDiv.querySelector('.no-grading-elements');
+            
+            // Charger les éléments de notation existants
+            exercise.grading_elements.forEach(element => {
+                const elementTemplate = document.getElementById('grading-element-template');
+                const elementDiv = elementTemplate.content.cloneNode(true);
+                
+                // Remplir les données de l'élément
+                elementDiv.querySelector('.element-label').value = element.label;
+                elementDiv.querySelector('.element-skill').value = element.skill || '';
+                elementDiv.querySelector('.element-max-points').value = element.max_points;
+                elementDiv.querySelector('.element-grading-type').value = element.grading_type;
+                elementDiv.querySelector('.element-description').value = element.description || '';
+                
+                // Ajouter l'event listener pour supprimer
+                const removeElementBtn = elementDiv.querySelector('.remove-grading-element');
+                removeElementBtn.addEventListener('click', function() {
+                    removeGradingElement(this);
+                });
+                
+                elementsContainer.appendChild(elementDiv);
+            });
+            
+            if (exercise.grading_elements.length > 0) {
+                noElementsMsg.style.display = 'none';
+            }
+            
+            exercisesContainer.appendChild(exerciseDiv);
+        });
+        
+        updateExercisesVisibility();
+    }
+    {% endif %}
+});
+</script>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/assessments.html b/templates/assessments.html
index faf6dc1..1a6ecef 100644
--- a/templates/assessments.html
+++ b/templates/assessments.html
@@ -6,9 +6,11 @@
 <div class="space-y-6">
     <div class="flex justify-between items-center">
         <h1 class="text-2xl font-bold text-gray-900">Gestion des évaluations</h1>
-        <a href="{{ url_for('assessments.new') }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md transition-colors">
-            Nouvelle évaluation
-        </a>
+        <div>
+            <a href="{{ url_for('assessments.new') }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md transition-colors text-sm font-medium focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2">
+                ✨ Nouvelle évaluation
+            </a>
+        </div>
     </div>
 
     {% if assessments %}
@@ -42,14 +44,14 @@
                                     </div>
                                 </div>
                                 <div class="flex space-x-2">
-                                    <a href="{{ url_for('assessments.detail', id=assessment.id) }}" class="text-indigo-600 hover:text-indigo-900 text-sm font-medium">
-                                        Voir détails
+                                    <a href="{{ url_for('assessments.detail', id=assessment.id) }}" class="text-indigo-600 hover:text-indigo-900 text-sm font-medium focus:outline-none focus:ring-2 focus:ring-indigo-500 focus:ring-offset-1 rounded-sm px-1 py-1" aria-label="Voir détails de {{ assessment.title }}">
+                                        👁️ Voir détails
                                     </a>
-                                    <a href="{{ url_for('grading.assessment_grading', assessment_id=assessment.id) }}" class="text-green-600 hover:text-green-900 text-sm font-medium">
-                                        Saisir notes
+                                    <a href="{{ url_for('grading.assessment_grading', assessment_id=assessment.id) }}" class="text-green-600 hover:text-green-900 text-sm font-medium focus:outline-none focus:ring-2 focus:ring-green-500 focus:ring-offset-1 rounded-sm px-1 py-1" aria-label="Saisir notes pour {{ assessment.title }}">
+                                        📝 Saisir notes
                                     </a>
-                                    <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="text-gray-600 hover:text-gray-900 text-sm font-medium">
-                                        Modifier
+                                    <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="text-gray-600 hover:text-gray-900 text-sm font-medium focus:outline-none focus:ring-2 focus:ring-gray-500 focus:ring-offset-1 rounded-sm px-1 py-1" aria-label="Modifier {{ assessment.title }}">
+                                        ✏️ Modifier
                                     </a>
                                 </div>
                             </div>
@@ -66,8 +68,8 @@
             <h3 class="mt-2 text-sm font-medium text-gray-900">Aucune évaluation</h3>
             <p class="mt-1 text-sm text-gray-500">Commencez par créer votre première évaluation.</p>
             <div class="mt-6">
-                <a href="{{ url_for('assessments.new') }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md transition-colors">
-                    Nouvelle évaluation
+                <a href="{{ url_for('assessments.new') }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md transition-colors text-sm font-medium focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2">
+                    ✨ Créer votre première évaluation
                 </a>
             </div>
         </div>
diff --git a/templates/base.html b/templates/base.html
index b59d89a..387faf4 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -5,34 +5,66 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>{% block title %}Gestion Scolaire{% endblock %}</title>
     <script src="https://cdn.tailwindcss.com"></script>
+    <script>
+        // Configuration Tailwind pour dark mode et focus
+        tailwind.config = {
+            theme: {
+                extend: {
+                    colors: {
+                        primary: {
+                            50: '#eff6ff',
+                            600: '#2563eb',
+                            700: '#1d4ed8',
+                        }
+                    }
+                }
+            }
+        }
+    </script>
 </head>
-<body class="bg-gray-100 min-h-screen">
-    <nav class="bg-blue-600 text-white shadow-lg">
+<body class="bg-gray-100 min-h-screen" role="document">
+    <nav class="bg-blue-600 text-white shadow-lg" role="navigation" aria-label="Navigation principale">
         <div class="max-w-7xl mx-auto px-4">
             <div class="flex justify-between items-center py-4">
                 <div class="flex items-center space-x-4">
                     <h1 class="text-xl font-bold">
-                        <a href="{{ url_for('index') }}" class="hover:text-blue-200">Gestion Scolaire</a>
+                        <a href="{{ url_for('index') }}" class="hover:text-blue-200 focus:outline-none focus:ring-2 focus:ring-blue-300 focus:ring-offset-2 focus:ring-offset-blue-600 rounded-sm" aria-label="Accueil - Gestion Scolaire">Gestion Scolaire</a>
                     </h1>
                 </div>
-                <div class="flex space-x-6">
-                    <a href="{{ url_for('index') }}" class="hover:text-blue-200 transition-colors">Accueil</a>
-                    <a href="{{ url_for('classes') }}" class="hover:text-blue-200 transition-colors">Classes</a>
-                    <a href="{{ url_for('students') }}" class="hover:text-blue-200 transition-colors">Élèves</a>
-                    <a href="{{ url_for('assessments.list') }}" class="hover:text-blue-200 transition-colors">Évaluations</a>
+                <div class="flex space-x-6" role="menubar">
+                    <a href="{{ url_for('index') }}" class="hover:text-blue-200 transition-colors focus:outline-none focus:ring-2 focus:ring-blue-300 focus:ring-offset-2 focus:ring-offset-blue-600 rounded-sm px-2 py-1" role="menuitem">Accueil</a>
+                    <a href="{{ url_for('classes') }}" class="hover:text-blue-200 transition-colors focus:outline-none focus:ring-2 focus:ring-blue-300 focus:ring-offset-2 focus:ring-offset-blue-600 rounded-sm px-2 py-1" role="menuitem">Classes</a>
+                    <a href="{{ url_for('students') }}" class="hover:text-blue-200 transition-colors focus:outline-none focus:ring-2 focus:ring-blue-300 focus:ring-offset-2 focus:ring-offset-blue-600 rounded-sm px-2 py-1" role="menuitem">Élèves</a>
+                    <a href="{{ url_for('assessments.list') }}" class="hover:text-blue-200 transition-colors focus:outline-none focus:ring-2 focus:ring-blue-300 focus:ring-offset-2 focus:ring-offset-blue-600 rounded-sm px-2 py-1" role="menuitem">Évaluations</a>
                 </div>
             </div>
         </div>
     </nav>
 
-    <main class="max-w-7xl mx-auto px-4 py-8">
+    <main class="max-w-7xl mx-auto px-4 py-8" role="main">
+        <!-- Messages flash améliorés pour l'accessibilité -->
         {% with messages = get_flashed_messages(with_categories=true) %}
             {% if messages %}
-                {% for category, message in messages %}
-                    <div class="mb-4 p-4 rounded-md {% if category == 'error' %}bg-red-100 text-red-700 border border-red-300{% else %}bg-green-100 text-green-700 border border-green-300{% endif %}">
-                        {{ message }}
-                    </div>
-                {% endfor %}
+                <div role="alert" aria-live="polite">
+                    {% for category, message in messages %}
+                        <div class="mb-4 p-4 rounded-md {% if category == 'error' %}bg-red-100 text-red-700 border border-red-300{% else %}bg-green-100 text-green-700 border border-green-300{% endif %}" role="alert">
+                            <div class="flex items-center">
+                                {% if category == 'error' %}
+                                    <svg class="w-5 h-5 mr-2" fill="currentColor" viewBox="0 0 20 20" aria-hidden="true">
+                                        <path fill-rule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clip-rule="evenodd"></path>
+                                    </svg>
+                                    <span class="sr-only">Erreur:</span>
+                                {% else %}
+                                    <svg class="w-5 h-5 mr-2" fill="currentColor" viewBox="0 0 20 20" aria-hidden="true">
+                                        <path fill-rule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zm3.707-9.293a1 1 0 00-1.414-1.414L9 10.586 7.707 9.293a1 1 0 00-1.414 1.414l2 2a1 1 0 001.414 0l4-4z" clip-rule="evenodd"></path>
+                                    </svg>
+                                    <span class="sr-only">Succès:</span>
+                                {% endif %}
+                                {{ message }}
+                            </div>
+                        </div>
+                    {% endfor %}
+                </div>
             {% endif %}
         {% endwith %}
 
diff --git a/templates/error.html b/templates/error.html
new file mode 100644
index 0000000..04914d2
--- /dev/null
+++ b/templates/error.html
@@ -0,0 +1,20 @@
+{% extends "base.html" %}
+
+{% block title %}Erreur - Gestion Scolaire{% endblock %}
+
+{% block content %}
+<div class="max-w-md mx-auto mt-16">
+    <div class="bg-red-50 border border-red-200 rounded-lg p-6 text-center">
+        <div class="mx-auto flex items-center justify-center h-12 w-12 rounded-full bg-red-100 mb-4">
+            <svg class="h-6 w-6 text-red-600" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.732-.833-2.5 0L4.268 18.5c-.77.833.192 2.5 1.732 2.5z"></path>
+            </svg>
+        </div>
+        <h1 class="text-lg font-medium text-gray-900 mb-2">Une erreur s'est produite</h1>
+        <p class="text-sm text-gray-600 mb-4">{{ error or "Une erreur inattendue s'est produite." }}</p>
+        <a href="{{ url_for('index') }}" class="inline-flex items-center px-4 py-2 border border-transparent text-sm font-medium rounded-md text-white bg-blue-600 hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-blue-500">
+            Retour à l'accueil
+        </a>
+    </div>
+</div>
+{% endblock %}
\ No newline at end of file
diff --git a/templates/exercise_detail.html b/templates/exercise_detail.html
index d26b0af..8b6e079 100644
--- a/templates/exercise_detail.html
+++ b/templates/exercise_detail.html
@@ -13,18 +13,12 @@
             <p class="text-gray-600">{{ assessment.title }} - {{ assessment.class_group.name }}</p>
         </div>
         <div class="flex space-x-3">
-            <a href="{{ url_for('exercises.edit', assessment_id=assessment.id, id=exercise.id) }}" class="bg-gray-600 hover:bg-gray-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
-                Modifier
+            <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
+                Modifier l'évaluation complète
             </a>
-            <button onclick="if(confirm('Êtes-vous sûr de vouloir supprimer cet exercice ?')) { document.getElementById('delete-form').submit(); }" 
-                    class="bg-red-600 hover:bg-red-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
-                Supprimer
-            </button>
         </div>
     </div>
     
-    <form id="delete-form" method="POST" action="{{ url_for('exercises.delete', assessment_id=assessment.id, id=exercise.id) }}" style="display: none;"></form>
-    
     <!-- Informations de l'exercice -->
     <div class="bg-white shadow rounded-lg">
         <div class="px-6 py-4 border-b border-gray-200">
@@ -54,8 +48,8 @@
     <div class="bg-white shadow rounded-lg">
         <div class="px-6 py-4 border-b border-gray-200 flex justify-between items-center">
             <h2 class="text-lg font-medium text-gray-900">Éléments de notation</h2>
-            <a href="{{ url_for('exercises.new_grading_element', assessment_id=assessment.id, exercise_id=exercise.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
-                Ajouter un élément
+            <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
+                Modifier l'évaluation complète
             </a>
         </div>
         <div class="px-6 py-4">
@@ -83,13 +77,9 @@
                                     </div>
                                 </div>
                                 <div class="flex space-x-2 ml-4">
-                                    <a href="{{ url_for('exercises.edit_grading_element', assessment_id=assessment.id, exercise_id=exercise.id, id=element.id) }}" class="text-gray-600 hover:text-gray-800 text-sm font-medium">
-                                        Modifier
-                                    </a>
-                                    <button onclick="if(confirm('Êtes-vous sûr de vouloir supprimer cet élément ?')) { document.getElementById('delete-element-{{ element.id }}').submit(); }" class="text-red-600 hover:text-red-800 text-sm font-medium">
-                                        Supprimer
-                                    </button>
-                                    <form id="delete-element-{{ element.id }}" method="POST" action="{{ url_for('exercises.delete_grading_element', assessment_id=assessment.id, exercise_id=exercise.id, id=element.id) }}" style="display: none;"></form>
+                                    <span class="text-xs text-gray-500">
+                                        Utilisez "Modifier l'évaluation complète" pour modifier
+                                    </span>
                                 </div>
                             </div>
                         </div>
@@ -103,8 +93,8 @@
                     <h3 class="mt-2 text-sm font-medium text-gray-900">Aucun élément de notation</h3>
                     <p class="mt-1 text-sm text-gray-500">Commencez par ajouter le premier élément de notation pour cet exercice.</p>
                     <div class="mt-6">
-                        <a href="{{ url_for('exercises.new_grading_element', assessment_id=assessment.id, exercise_id=exercise.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
-                            Ajouter un élément
+                        <a href="{{ url_for('assessments.edit', id=assessment.id) }}" class="bg-blue-600 hover:bg-blue-700 text-white px-4 py-2 rounded-md text-sm font-medium transition-colors">
+                            Modifier l'évaluation complète
                         </a>
                     </div>
                 </div>
diff --git a/templates/exercise_form.html b/templates/exercise_form.html
deleted file mode 100644
index 3d80c34..0000000
--- a/templates/exercise_form.html
+++ /dev/null
@@ -1,74 +0,0 @@
-{% extends "base.html" %}
-
-{% block title %}{{ title }} - Gestion Scolaire{% endblock %}
-
-{% block content %}
-<div class="max-w-2xl mx-auto">
-    <div class="mb-6">
-        <a href="{{ url_for('assessments.detail', id=assessment.id) }}" class="text-blue-600 hover:text-blue-800 text-sm font-medium">
-            ← Retour à l'évaluation "{{ assessment.title }}"
-        </a>
-    </div>
-    
-    <div class="bg-white shadow rounded-lg">
-        <div class="px-6 py-4 border-b border-gray-200">
-            <h1 class="text-xl font-semibold text-gray-900">{{ title }}</h1>
-            <p class="text-sm text-gray-600 mt-1">Évaluation : {{ assessment.title }} ({{ assessment.class_group.name }})</p>
-        </div>
-        
-        <form method="POST" class="px-6 py-4 space-y-6">
-            {{ form.hidden_tag() }}
-            
-            <div>
-                <label for="{{ form.title.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.title.label.text }}
-                </label>
-                {{ form.title(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                {% if form.title.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.title.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-            </div>
-            
-            <div>
-                <label for="{{ form.description.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.description.label.text }}
-                </label>
-                {{ form.description(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500", rows="3") }}
-                {% if form.description.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.description.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-            </div>
-            
-            <div>
-                <label for="{{ form.order.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.order.label.text }}
-                </label>
-                {{ form.order(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                {% if form.order.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.order.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-                <p class="mt-1 text-xs text-gray-500">L'ordre détermine l'affichage des exercices dans l'évaluation</p>
-            </div>
-            
-            <div class="flex justify-end space-x-3 pt-4 border-t border-gray-200">
-                <a href="{{ url_for('assessments.detail', id=assessment.id) }}" class="px-4 py-2 border border-gray-300 rounded-md text-sm font-medium text-gray-700 hover:bg-gray-50 transition-colors">
-                    Annuler
-                </a>
-                {{ form.submit(class="px-4 py-2 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700 transition-colors") }}
-            </div>
-        </form>
-    </div>
-</div>
-{% endblock %}
\ No newline at end of file
diff --git a/templates/grading_element_form.html b/templates/grading_element_form.html
deleted file mode 100644
index b42819e..0000000
--- a/templates/grading_element_form.html
+++ /dev/null
@@ -1,114 +0,0 @@
-{% extends "base.html" %}
-
-{% block title %}{{ title }} - Gestion Scolaire{% endblock %}
-
-{% block content %}
-<div class="max-w-2xl mx-auto">
-    <div class="mb-6">
-        <a href="{{ url_for('exercises.detail', assessment_id=assessment.id, id=exercise.id) }}" class="text-blue-600 hover:text-blue-800 text-sm font-medium">
-            ← Retour à l'exercice "{{ exercise.title }}"
-        </a>
-    </div>
-    
-    <div class="bg-white shadow rounded-lg">
-        <div class="px-6 py-4 border-b border-gray-200">
-            <h1 class="text-xl font-semibold text-gray-900">{{ title }}</h1>
-            <p class="text-sm text-gray-600 mt-1">{{ assessment.title }} > {{ exercise.title }}</p>
-        </div>
-        
-        <form method="POST" class="px-6 py-4 space-y-6">
-            {{ form.hidden_tag() }}
-            
-            <div>
-                <label for="{{ form.label.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.label.label.text }}
-                </label>
-                {{ form.label(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                {% if form.label.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.label.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-                <p class="mt-1 text-xs text-gray-500">Ex: "Calcul de base", "Méthode", "Présentation"</p>
-            </div>
-            
-            <div>
-                <label for="{{ form.description.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.description.label.text }}
-                </label>
-                {{ form.description(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500", rows="3") }}
-                {% if form.description.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.description.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-            </div>
-            
-            <div>
-                <label for="{{ form.skill.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                    {{ form.skill.label.text }}
-                </label>
-                {{ form.skill(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                {% if form.skill.errors %}
-                    <div class="mt-1 text-sm text-red-600">
-                        {% for error in form.skill.errors %}
-                            <p>{{ error }}</p>
-                        {% endfor %}
-                    </div>
-                {% endif %}
-                <p class="mt-1 text-xs text-gray-500">Ex: "Calculer", "Raisonner", "Communiquer"</p>
-            </div>
-            
-            <div class="grid grid-cols-1 md:grid-cols-2 gap-6">
-                <div>
-                    <label for="{{ form.max_points.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                        {{ form.max_points.label.text }}
-                    </label>
-                    {{ form.max_points(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500", step="0.1") }}
-                    {% if form.max_points.errors %}
-                        <div class="mt-1 text-sm text-red-600">
-                            {% for error in form.max_points.errors %}
-                                <p>{{ error }}</p>
-                            {% endfor %}
-                        </div>
-                    {% endif %}
-                </div>
-                
-                <div>
-                    <label for="{{ form.grading_type.id }}" class="block text-sm font-medium text-gray-700 mb-1">
-                        {{ form.grading_type.label.text }}
-                    </label>
-                    {{ form.grading_type(class="block w-full border border-gray-300 rounded-md px-3 py-2 focus:ring-blue-500 focus:border-blue-500") }}
-                    {% if form.grading_type.errors %}
-                        <div class="mt-1 text-sm text-red-600">
-                            {% for error in form.grading_type.errors %}
-                                <p>{{ error }}</p>
-                            {% endfor %}
-                        </div>
-                    {% endif %}
-                </div>
-            </div>
-            
-            <!-- Aide sur les types de notation -->
-            <div class="bg-blue-50 border border-blue-200 rounded-md p-4">
-                <h4 class="text-sm font-medium text-blue-900 mb-2">Types de notation</h4>
-                <div class="text-xs text-blue-800 space-y-1">
-                    <p><strong>Points :</strong> Notation classique (ex: 2.5/4 points)</p>
-                    <p><strong>Score :</strong> Évaluation par niveaux (0=non acquis, 1=en cours, 2=acquis, 3=expert, .=non évalué)</p>
-                </div>
-            </div>
-            
-            <div class="flex justify-end space-x-3 pt-4 border-t border-gray-200">
-                <a href="{{ url_for('exercises.detail', assessment_id=assessment.id, id=exercise.id) }}" class="px-4 py-2 border border-gray-300 rounded-md text-sm font-medium text-gray-700 hover:bg-gray-50 transition-colors">
-                    Annuler
-                </a>
-                {{ form.submit(class="px-4 py-2 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700 transition-colors") }}
-            </div>
-        </form>
-    </div>
-</div>
-{% endblock %}
\ No newline at end of file
diff --git a/templates/index.html b/templates/index.html
index 79d64f9..78be5c8 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -114,7 +114,7 @@
                         <div class="text-sm font-medium text-gray-900">Gérer les élèves</div>
                     </div>
                 </a>
-                <a href="{{ url_for('assessments.list') }}" class="block p-4 border border-gray-200 rounded-lg hover:bg-gray-50 transition-colors">
+                <a href="{{ url_for('assessments.new') }}" class="block p-4 border border-gray-200 rounded-lg hover:bg-gray-50 transition-colors">
                     <div class="text-center">
                         <div class="w-8 h-8 bg-purple-100 rounded-full flex items-center justify-center mx-auto mb-2">
                             <svg class="w-4 h-4 text-purple-600" fill="currentColor" viewBox="0 0 20 20">
diff --git a/utils.py b/utils.py
new file mode 100644
index 0000000..41c9c77
--- /dev/null
+++ b/utils.py
@@ -0,0 +1,94 @@
+from functools import wraps
+from flask import current_app, flash, jsonify, request, render_template, redirect, url_for
+from models import db
+from sqlalchemy.exc import SQLAlchemyError, IntegrityError
+from decimal import Decimal, InvalidOperation
+import logging
+
+def handle_db_errors(f):
+    """Décorateur pour gérer les erreurs de base de données"""
+    @wraps(f)
+    def decorated_function(*args, **kwargs):
+        try:
+            result = f(*args, **kwargs)
+            # Vérifier que le résultat est une réponse Flask valide
+            if result is None:
+                current_app.logger.error(f'Fonction {f.__name__} a retourné None')
+                return render_template('error.html', error="Une erreur inattendue s'est produite."), 500
+            return result
+        except IntegrityError as e:
+            db.session.rollback()
+            current_app.logger.error(f'Erreur d\'intégrité dans {f.__name__}: {e}')
+            
+            error_msg = "Une erreur s'est produite lors de l'enregistrement."
+            if "UNIQUE constraint failed" in str(e):
+                error_msg = "Cette donnée existe déjà."
+            elif "CHECK constraint failed" in str(e):
+                error_msg = "Les données saisies ne respectent pas les contraintes."
+                
+            if request.is_json:
+                return jsonify({'success': False, 'error': error_msg}), 400
+            else:
+                flash(error_msg, 'error')
+                return render_template('error.html', error=error_msg), 400
+                
+        except SQLAlchemyError as e:
+            db.session.rollback()
+            current_app.logger.error(f'Erreur SQLAlchemy dans {f.__name__}: {e}')
+            
+            error_msg = "Une erreur de base de données s'est produite."
+            if request.is_json:
+                return jsonify({'success': False, 'error': error_msg}), 500
+            else:
+                flash(error_msg, 'error')
+                return render_template('error.html', error=error_msg), 500
+                
+        except Exception as e:
+            db.session.rollback()
+            current_app.logger.error(f'Erreur inattendue dans {f.__name__}: {e}')
+            
+            error_msg = "Une erreur inattendue s'est produite."
+            if request.is_json:
+                return jsonify({'success': False, 'error': error_msg}), 500
+            else:
+                flash(error_msg, 'error')
+                return render_template('error.html', error=error_msg), 500
+                
+    return decorated_function
+
+def safe_int_conversion(value, field_name="valeur"):
+    """Conversion sécurisée en entier"""
+    if value is None:
+        return None
+    try:
+        return int(value)
+    except (ValueError, TypeError):
+        raise ValueError(f"La {field_name} doit être un nombre entier valide.")
+
+def safe_decimal_conversion(value, field_name="valeur"):
+    """Conversion sécurisée en décimal"""
+    if value is None:
+        return None
+    try:
+        return Decimal(str(value))
+    except (ValueError, TypeError, InvalidOperation):
+        raise ValueError(f"La {field_name} doit être un nombre décimal valide.")
+
+def validate_json_data(data, required_fields):
+    """Valide les données JSON et vérifie les champs requis"""
+    if not data:
+        raise ValueError("Aucune donnée fournie.")
+    
+    missing_fields = [field for field in required_fields if field not in data or data[field] is None]
+    if missing_fields:
+        raise ValueError(f"Champs requis manquants: {', '.join(missing_fields)}")
+    
+    return True
+
+def log_user_action(action, details=None):
+    """Log les actions utilisateur pour audit"""
+    current_app.logger.info(f"Action utilisateur: {action}" + (f" - {details}" if details else ""))
+
+class ValidationError(Exception):
+    """Exception personnalisée pour les erreurs de validation"""
+    pass
\ No newline at end of file