dark mode. new COB style

web/layout_manager.py

@@ -15,12 +15,16 @@ class DashboardLayoutManager:
         self.trading_executor = trading_executor
     
     def create_main_layout(self):
-        """Create the main dashboard layout"""
+        """Create the main dashboard layout with dark theme"""
         return html.Div([
             self._create_header(),
             self._create_interval_component(),
             self._create_main_content()
-        ], className="container-fluid")
+        ], className="container-fluid", style={
+            "backgroundColor": "#111827",
+            "minHeight": "100vh",
+            "color": "#f8f9fa"
+        })
     
     def _create_header(self):
         """Create the dashboard header"""
@@ -84,7 +88,12 @@ class DashboardLayoutManager:
                     html.H5(id=card_id, className=f"{text_class} mb-0 small"),
                     html.P(label, className="text-muted mb-0 tiny")
                 ], className="card-body text-center p-2")
-            ], className="card bg-light", style={"height": "60px"})
+            ], className="card", style={
+                "height": "60px", 
+                "backgroundColor": "#1f2937", 
+                "border": "1px solid #374151",
+                "color": "#f8f9fa"
+            })
             cards.append(card)
         
         return html.Div(