diff --git a/dashboard/app.py b/dashboard/app.py
index c37147c..10e3bcf 100644
--- a/dashboard/app.py
+++ b/dashboard/app.py
@@ -47,13 +47,21 @@ def execute(sql, params=None):
     finally:
         conn.close()
 
-def load_sim_config(session_id: int) -> dict:
+_REFERENCE_CONFIG_ID = 1  # sim_001.json = référence pour la liste des modes
+
+def load_sim_config(session_id: int) -> dict | None:
+    """Retourne le cfg JSON ou None si introuvable (None est falsy ET distinguable de {})."""
     path = os.path.join(SIM_CONFIGS_DIR, f"sim_{session_id:03d}.json")
     try:
         with open(path) as f:
             return json.load(f)
-    except Exception:
-        return {}
+    except Exception as e:
+        return None
+
+def load_all_modes() -> dict:
+    """Charge les modes depuis sim_001.json (référence complète des 5 modes)."""
+    cfg = load_sim_config(_REFERENCE_CONFIG_ID) or {}
+    return cfg.get("modes", {})
 
 def save_sim_config(session_id: int, cfg: dict):
     path = os.path.join(SIM_CONFIGS_DIR, f"sim_{session_id:03d}.json")
@@ -407,7 +415,7 @@ if (el) {
   <div class="panel">
     <h2>⚙ CONFIG SIM_{{ '%03d' % current_sid }}.JSON</h2>
     <form method="POST" action="/params/save?sid={{ current_sid }}">
-    {% if cfg %}
+    {% if cfg is not none %}
 
       <div class="cfg-block">
         <h3>GÉNÉRAL</h3>
@@ -466,8 +474,17 @@ if (el) {
       </div>
 
       <button type="submit" class="btn btn-green">💾 SAUVEGARDER CONFIG</button>
+      <p style="margin-top:6px;font-size:10px;color:#555">
+        ⚠ Prise en compte au prochain jour (J{{ (session.current_day or 0) + 1 }}).
+        Pour effet immédiat : STOP → relancer via terminal.
+      </p>
     {% else %}
-      <p style="color:#ff4444;font-size:11px">Fichier sim_{{ '%03d' % current_sid }}.json introuvable dans {{ sim_configs_dir }}</p>
+      <p style="color:#ff4444;font-size:11px">
+        Fichier <code>sim_{{ '%03d' % current_sid }}.json</code> introuvable dans <code>{{ sim_configs_dir }}</code>
+      </p>
+      <p style="color:#555;font-size:10px;margin-top:4px">
+        Vérifier le mount Docker : /home/ubuntu/fallout-venice/src/config → /app/src/config
+      </p>
     {% endif %}
     </form>
   </div>
@@ -673,7 +690,7 @@ def params():
     sid = int(request.args.get("sid", all_sessions[-1]["id"] if all_sessions else 1))
     session = query_one("SELECT * FROM sessions WHERE id = %s", (sid,))
     cfg = load_sim_config(sid)
-    modes = cfg.get("modes", {})
+    modes = load_all_modes()  # toujours les 5 modes depuis sim_001 (référence)
     flash_msg = request.args.get("msg")
     flash_ok = request.args.get("ok", "1") == "1"
     return render_template_string(TEMPLATE,
@@ -697,8 +714,8 @@ def params():
 def params_save():
     sid = int(request.args.get("sid", 1))
     cfg = load_sim_config(sid)
-    if not cfg:
-        return redirect(url_for("params", sid=sid, msg="Fichier config introuvable", ok=0))
+    if cfg is None:
+        return redirect(url_for("params", sid=sid, msg=f"Fichier sim_{sid:03d}.json introuvable dans {SIM_CONFIGS_DIR}", ok=0))
 
     f = request.form
 
diff --git a/src/engine/run.py b/src/engine/run.py
index c27b6fe..947bff2 100644
--- a/src/engine/run.py
+++ b/src/engine/run.py
@@ -77,8 +77,12 @@ def run(config_path: str | None = None):
 
             day, current_tick = tick_engine.next_tick(day, current_tick)
 
-            # Réinit world_state au début de chaque nouveau jour
+            # Début d'un nouveau jour : hot-reload config depuis le JSON (permet les changements dashboard)
             if current_tick == 0:
+                cfg.load(config_path, session_id=SESSION_ID)
+                effective_mode = cfg.mode() or db_mode
+                tick_sleep = float(os.getenv("TICK_SLEEP_SEC",
+                                             cfg.get("tick", {}).get("tick_sleep_sec", tick_sleep)))
                 _init_world_state(SESSION_ID, day)
 
     except KeyboardInterrupt: