feat(ui): 重做三 Tab 首页与发现页

lib/core/widgets/app_bottom_nav.dart

@@ -1,5 +1,7 @@
 // Author: fruit.com.cn
 
+import 'dart:ui';
+
 import 'package:flutter/material.dart';
 
 import '../theme/app_colors.dart';
@@ -14,6 +16,7 @@ class AppBottomNavItem {
     required this.label,
     required this.onTap,
     this.selected = false,
+    this.indicatorKey,
   });
 
   final Key tabKey;
@@ -22,9 +25,10 @@ class AppBottomNavItem {
   final String label;
   final VoidCallback onTap;
   final bool selected;
+  final Key? indicatorKey;
 }
 
-/// Shared bottom navigation used by all root tabs and the player fallback.
+/// Shared 3-tab navigation used by all root tabs and the player fallback.
 class AppBottomNav extends StatelessWidget {
   const AppBottomNav({
     super.key,
@@ -38,20 +42,23 @@ class AppBottomNav extends StatelessWidget {
   final Key? barKey;
 
   @override
-  Widget build(BuildContext context) => SafeArea(
-    top: false,
-    child: Container(
-      key: barKey,
-      height: AppDimens.navHeight,
-      decoration: BoxDecoration(
-        color: backgroundColor,
-        border: const Border(
-          top: BorderSide(color: AppColors.outlineVariantDark),
+  Widget build(BuildContext context) => ClipRect(
+    child: BackdropFilter(
+      filter: ImageFilter.blur(sigmaX: 20, sigmaY: 20),
+      child: SafeArea(
+        top: false,
+        child: Container(
+          key: barKey,
+          height: AppDimens.navHeight,
+          decoration: BoxDecoration(
+            color: backgroundColor.withValues(alpha: 0.95),
+            border: const Border(top: BorderSide(color: AppColors.border)),
+          ),
+          child: Row(
+            children: [for (final item in items) _NavDestination(item: item)],
+          ),
         ),
       ),
-      child: Row(
-        children: [for (final item in items) _NavDestination(item: item)],
-      ),
     ),
   );
 }
@@ -71,28 +78,23 @@ class _NavDestination extends StatelessWidget {
         key: item.tabKey,
         onTap: item.onTap,
         child: ConstrainedBox(
-          constraints: const BoxConstraints(minHeight: AppDimens.tapTarget),
+          constraints: const BoxConstraints(minHeight: 48),
           child: Column(
             mainAxisAlignment: MainAxisAlignment.center,
             children: [
-              AnimatedContainer(
+              AnimatedScale(
                 duration: const Duration(milliseconds: 160),
                 curve: Curves.easeOut,
-                padding: const EdgeInsets.symmetric(
-                  horizontal: 14,
-                  vertical: 3,
-                ),
-                decoration: BoxDecoration(
-                  color: item.selected ? AppColors.blue : Colors.transparent,
-                  borderRadius: BorderRadius.circular(AppDimens.pillRadius),
-                ),
+                scale: item.selected ? 1 : 0.96,
                 child: Icon(
                   item.selected ? item.selectedIcon : item.icon,
                   size: AppDimens.navIcon,
-                  color: item.selected ? AppColors.onPrimary : AppColors.muted,
+                  color: item.selected
+                      ? AppColors.blue
+                      : Colors.white.withValues(alpha: 0.45),
                 ),
               ),
-              const SizedBox(height: 2),
+              const SizedBox(height: 3),
               Text(
                 item.label,
                 maxLines: 1,
@@ -100,7 +102,22 @@ class _NavDestination extends StatelessWidget {
                 style: TextStyle(
                   fontSize: AppDimens.navLabel,
                   fontWeight: item.selected ? FontWeight.w700 : FontWeight.w500,
-                  color: item.selected ? AppColors.blueSoft : AppColors.muted,
+                  color: item.selected
+                      ? AppColors.blue
+                      : Colors.white.withValues(alpha: 0.45),
+                  letterSpacing: 0,
+                ),
+              ),
+              const SizedBox(height: 3),
+              AnimatedContainer(
+                key: item.indicatorKey,
+                duration: const Duration(milliseconds: 160),
+                curve: Curves.easeOut,
+                width: AppDimens.navDot,
+                height: AppDimens.navDot,
+                decoration: BoxDecoration(
+                  color: item.selected ? AppColors.blue : Colors.transparent,
+                  shape: BoxShape.circle,
                 ),
               ),
             ],