优化页面不同机型适配问题

lib/pages/mine/user_help_center_page.dart

@@ -50,10 +50,8 @@ class _UserHelpCenterPageState extends State<UserHelpCenterPage> {
   Widget build(BuildContext context) {
     return Stack(
       children: [
-        Positioned(
+        Positioned.fill(
           child: Container(
-            width: 375.w,
-            height: 821.h,
             color: Colors.white,
           ),
         ),

lib/pages/mine/vip_page.dart

@@ -42,11 +42,10 @@ class _VipPageState extends State<VipPage> {
   @override
   Widget build(BuildContext context) {
     return Stack(
+
       children: [
-        Positioned(
+        Positioned.fill(
           child: Container(
-            width: 375.w,
-            height: 812.h,
             color: Colors.white,
           ),
         ),
@@ -216,31 +215,6 @@ class _VipPageState extends State<VipPage> {
                           }),
                         ],
                       ),
-                      Row(
-                        children: [
-
-                          Checkbox(
-                            value: checked,
-                            onChanged: (value) {
-                              checked = value ?? false;
-                              setState(() {
-
-                              });
-                            },
-                            activeColor: const Color.fromRGBO(117, 98, 249, 1),
-                            side: const BorderSide(color: Colors.grey),
-                            shape: const CircleBorder(),
-                            materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
-                          ),
-                          Text(
-                            "我已阅读并同意《会员购买协议》",
-                            style: TextStyle(
-                                fontSize: 11.w,
-                                color: const Color.fromRGBO(189, 189, 189, 1)
-                            ),
-                          )
-                        ],
-                      ),
                       Row(
                         children: [
                           Text(
@@ -388,7 +362,7 @@ class _VipPageState extends State<VipPage> {
                       });
                     }),
                     Container(
-                      width: 80.w,
+                      width: 100.w,
                       height: 30.w,
                       padding: EdgeInsets.symmetric(
                           horizontal: 12.w
@@ -410,7 +384,7 @@ class _VipPageState extends State<VipPage> {
                             width: 17.w,
                           ),
                           Text(
-                            "支付宝",
+                            "支付宝支付",
                             style: TextStyle(
                                 fontSize: 11.w,
                                 fontWeight: FontWeight.w500
@@ -426,7 +400,31 @@ class _VipPageState extends State<VipPage> {
                     }),
                   ],
                 ),
-                SizedBox(height: 10.w,),
+                Row(
+                  children: [
+
+                    Checkbox(
+                      value: checked,
+                      onChanged: (value) {
+                        checked = value ?? false;
+                        setState(() {
+
+                        });
+                      },
+                      activeColor: const Color.fromRGBO(117, 98, 249, 1),
+                      side: const BorderSide(color: Colors.grey),
+                      shape: const CircleBorder(),
+                      materialTapTargetSize: MaterialTapTargetSize.shrinkWrap,
+                    ),
+                    Text(
+                      "我已阅读并同意《会员购买协议》",
+                      style: TextStyle(
+                          fontSize: 11.w,
+                          color: const Color.fromRGBO(189, 189, 189, 1)
+                      ),
+                    )
+                  ],
+                ),
                 Container(
                   width: 350.w,
                   height: 45.w,