better visual coherence

frontend/lib/constants.dart

@@ -13,6 +13,11 @@ const Color GRADIENT_END = Color(0xFFE72E77);
 
 const Color PRIMARY_COLOR = Color(0xFFF38F1A);
 
+
+
+const double TRIP_PANEL_MAX_HEIGHT = 0.8;
+const double TRIP_PANEL_MIN_HEIGHT = 0.12;
+
 ThemeData APP_THEME = ThemeData(
   primaryColor: PRIMARY_COLOR,
 
@@ -33,20 +38,43 @@ ThemeData APP_THEME = ThemeData(
   ),
 
 
-  textButtonTheme: TextButtonThemeData(
-    
-    style: TextButton.styleFrom(
-      backgroundColor: PRIMARY_COLOR,
-      textStyle: TextStyle(
-        color: Colors.red
-      )
+  textButtonTheme: const TextButtonThemeData(
+    style: ButtonStyle(
+      foregroundColor: WidgetStatePropertyAll(PRIMARY_COLOR),
+      side: WidgetStatePropertyAll(
+        BorderSide(
+          color: PRIMARY_COLOR,
+          width: 1,
+        ),
+      ),
+    )
     ),
-  ),
-  buttonTheme: ButtonThemeData(
-    buttonColor: PRIMARY_COLOR,
-    textTheme: ButtonTextTheme.primary,
+
+  elevatedButtonTheme: const ElevatedButtonThemeData(
+    style: ButtonStyle(
+      foregroundColor: WidgetStatePropertyAll(PRIMARY_COLOR),
+    )
   ),
 
+  outlinedButtonTheme: const OutlinedButtonThemeData(
+    style: ButtonStyle(
+      foregroundColor: WidgetStatePropertyAll(PRIMARY_COLOR),
+    )
+  ),
+
+
+  cardTheme: const CardTheme(
+    shadowColor: Colors.grey,
+    elevation: 2,
+    margin: EdgeInsets.all(10),
+  ),
+
+  sliderTheme: const SliderThemeData(
+    trackHeight: 15,
+    inactiveTrackColor: Colors.grey,
+    thumbColor: PRIMARY_COLOR,
+    activeTrackColor: GRADIENT_END
+  )
 );