layout fixes (#18)

- update layout (abb3339337ba80ce85705197e861e0b21e9800d0)

src/app.py

@@ -758,24 +758,37 @@ with tab_single:
         else:
             # Create two columns for side-by-side display
             col_result, col_candidates = st.columns([1.2, 1])
-            
+                                
+            # Calculer l'impact pour l'affichage
+            if result.impact_kg_co2_eq is not None:
+                if "tonne" in (result.unite_source or ""):
+                    impact_kg_t = result.impact_kg_co2_eq
+                else:
+                    impact_kg_t = result.impact_kg_co2_eq * 1000.0
+
+            # --- Forfait transport ---
+            transport_val, transport_zone = _get_transport_surcharge(
+                pays_production=result.pays_production,
+                pays_transformation=result.pays_transformation,
+                type_mp=type_mp_code,
+                source_db=result.source_db,
+                classification=result.classification,
+            )
+
+            # --- Forfait extrusion ---
+            extrusion_val = config.FORFAIT_EXTRUSION if extrusion_single else 0.0
+            impact_total = impact_kg_t + transport_val + extrusion_val
+
             # ========================================================================
             # LEFT COLUMN: Résultat de l'impact carbone
             # ========================================================================
             with col_result:
                 with st.container():
                     st.markdown("### 📊 Résultat de l'impact carbone")
-                    
-                    # Calculer l'impact pour l'affichage
-                    if result.impact_kg_co2_eq is not None:
-                        if "tonne" in (result.unite_source or ""):
-                            impact_kg_t = result.impact_kg_co2_eq
-                        else:
-                            impact_kg_t = result.impact_kg_co2_eq * 1000.0
 
                     st.metric(
-                        label="Impact carbone (MP)",
-                        value=f"{impact_kg_t:.2f}",
+                        label="🌍 Impact carbone Total (MP + Transport)",
+                        value=f"{impact_total:.2f}",
                         delta="kg CO2 eq / t produit",
                     )
 
@@ -800,20 +813,6 @@ with tab_single:
 
                     st.markdown("---")
 
-
-                    # --- Forfait transport ---
-                    transport_val, transport_zone = _get_transport_surcharge(
-                        pays_production=result.pays_production,
-                        pays_transformation=result.pays_transformation,
-                        type_mp=type_mp_code,
-                        source_db=result.source_db,
-                        classification=result.classification,
-                    )
-
-                        # --- Forfait extrusion ---
-                    extrusion_val = config.FORFAIT_EXTRUSION if extrusion_single else 0.0
-                    impact_total = impact_kg_t + transport_val + extrusion_val
-
                     # Affichage des impacts
                     st.markdown("#### 🎯 Impacts calculés")