fix(feedback)：提交按钮不浮动

@@ -46,62 +46,68 @@ class SubmitFeedbackView extends GetView<SubmitFeedbackController> {
           ),
           ),
         ),
         ),
       ),
       ),
-      body: Stack(
-        children: [
-          ListView(
-            physics: const ClampingScrollPhysics(),
-            padding: EdgeInsets.fromLTRB(
-              15,
-              16,
-              16,
-              132 + MediaQuery.paddingOf(context).bottom,
+      body: CustomScrollView(
+        physics: const ClampingScrollPhysics(),
+        slivers: [
+          SliverPadding(
+            padding: const EdgeInsets.fromLTRB(15, 16, 16, 0),
+            sliver: SliverList(
+              delegate: SliverChildListDelegate([
+                const _FeedbackLabel(),
+                SizedBox(height: 9),
+                const _FeedbackInput(),
+                SizedBox(height: 20),
+                _SectionLabel(context.l10n.contactInformation),
+                SizedBox(height: 8),
+                const _ContactInput(),
+                SizedBox(height: 20),
+                const _UploadHeader(),
+                SizedBox(height: 8),
+                const _ImagePickerGrid(),
+              ]),
             ),
             ),
-            children: [
-              const _FeedbackLabel(),
-              SizedBox(height: 9),
-              const _FeedbackInput(),
-              SizedBox(height: 20),
-              _SectionLabel(context.l10n.contactInformation),
-              SizedBox(height: 8),
-              const _ContactInput(),
-              SizedBox(height: 20),
-              const _UploadHeader(),
-              SizedBox(height: 8),
-              const _ImagePickerGrid(),
-            ],
           ),
           ),
-          Positioned(
-            left: 0,
-            right: 0,
-            bottom: 36 + MediaQuery.paddingOf(context).bottom,
-            child: Center(
-              child: Obx(() {
-                final isEmpty = controller.isFeedbackEmpty.value;
-                return GestureDetector(
-                  behavior: HitTestBehavior.opaque,
-                  onTap: isEmpty ? null : controller.submit,
-                  child: Opacity(
-                    opacity: isEmpty ? 0.4 : 1.0,
-                    child: Container(
-                      width: 280,
-                      height: 48,
-                      alignment: Alignment.center,
-                      decoration: BoxDecoration(
-                        color: AppColors.primary,
-                        borderRadius: BorderRadius.circular(24),
-                      ),
-                      child: Text(
-                        AppLocalizations.of(context)!.submit,
-                        style: TextStyle(
-                          color: Colors.white,
-                          fontSize: 16,
-                          fontWeight: FontWeight.w600,
+          SliverFillRemaining(
+            hasScrollBody: false,
+            child: Column(
+              children: [
+                const Spacer(),
+                Padding(
+                  padding: EdgeInsets.only(
+                    top: 40,
+                    bottom: 36 + MediaQuery.paddingOf(context).bottom,
+                  ),
+                  child: Center(
+                    child: Obx(() {
+                      final isEmpty = controller.isFeedbackEmpty.value;
+                      return GestureDetector(
+                        behavior: HitTestBehavior.opaque,
+                        onTap: isEmpty ? null : controller.submit,
+                        child: Opacity(
+                          opacity: isEmpty ? 0.4 : 1.0,
+                          child: Container(
+                            width: 280,
+                            height: 48,
+                            alignment: Alignment.center,
+                            decoration: BoxDecoration(
+                              color: AppColors.primary,
+                              borderRadius: BorderRadius.circular(24),
+                            ),
+                            child: Text(
+                              AppLocalizations.of(context)!.submit,
+                              style: TextStyle(
+                                color: Colors.white,
+                                fontSize: 16,
+                                fontWeight: FontWeight.w600,
+                              ),
+                            ),
+                          ),
                         ),
                         ),
-                      ),
-                    ),
+                      );
+                    }),
                   ),
                   ),
-                );
-              }),
+                ),
+              ],
             ),
             ),
           ),
           ),
         ],
         ],