change page navigation

lib/pages/rates/shipment_rates.dart

@@ -7,6 +7,7 @@ import 'package:fcs/pages/rates/model/shipment_rate_model.dart';
 import 'package:fcs/pages/widgets/bottom_up_page_route.dart';
 import 'package:fcs/pages/widgets/local_text.dart';
 import 'package:fcs/pages/widgets/progress.dart';
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
@@ -44,9 +45,7 @@ class _ShipmentRatesState extends State<ShipmentRates> {
         appBar: AppBar(
           centerTitle: true,
           leading: new IconButton(
-            icon: new Icon(
-              Icons.close,
-            ),
+            icon: new Icon(CupertinoIcons.back),
             onPressed: () => Navigator.of(context).pop(),
           ),
           backgroundColor: primaryColor,
@@ -129,12 +128,12 @@ class _ShipmentRatesState extends State<ShipmentRates> {
               //       .push(MaterialPageRoute(builder: (_) => Term()));
               // }),
               fcsButton(context, "Estimate shipping cost", callack: () {
-                Navigator.of(context)
-                    .push(BottomUpPageRoute(ShipmentRatesCal()));
+                Navigator.of(context).push(CupertinoPageRoute(
+                    builder: (context) => ShipmentRatesCal()));
               }),
               fcsButton(context, "Edit", callack: () {
-                Navigator.of(context)
-                    .push(BottomUpPageRoute(ShipmentRatesEdit()));
+                Navigator.of(context).push(CupertinoPageRoute(
+                    builder: (context) => ShipmentRatesEdit()));
               }),
               SizedBox(height: 10)
             ],