style: 统一全站深色视觉

lib/pages/wallet/wallet_page.dart

@@ -183,20 +183,9 @@ class _BalanceHero extends StatelessWidget {
       key: const Key('wallet-balance-card'),
       padding: const EdgeInsets.fromLTRB(20, 22, 20, 20),
       decoration: BoxDecoration(
-        borderRadius: BorderRadius.circular(20),
-        gradient: const LinearGradient(
-          begin: Alignment.topLeft,
-          end: Alignment.bottomRight,
-          colors: [AppColors.goldCard, AppColors.card],
-        ),
-        border: Border.all(color: AppColors.gold.withValues(alpha: 0.35)),
-        boxShadow: [
-          BoxShadow(
-            color: AppColors.gold.withValues(alpha: 0.08),
-            blurRadius: 28,
-            offset: const Offset(0, 14),
-          ),
-        ],
+        color: AppColors.card,
+        borderRadius: BorderRadius.circular(AppDimens.cardRadius),
+        border: Border.all(color: AppColors.border),
       ),
       child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,