fix(theme): 修复亮色模式绿色对比度不足问题

- 添加主题感知颜色函数: getUpColor/getUpBackgroundColor
- app_color_scheme: 新增 getBuyGradient/getEmeraldGradient
- asset_card: emeraldGradient 支持主题切换
- neon_glow: 按钮颜色主题感知
- home_page: 涨跌颜色动态适配
- asset_page: 资产涨跌颜色适配
- trade_page: 交易涨跌颜色适配
- mine_page: 我的页面颜色适配

修复: 亮色模式下绿色 (#00a878) 与浅色背景对比度不足
效果: 亮色模式使用深绿色，深色模式使用亮绿色

flutter_monisuo/lib/ui/components/asset_card.dart

@@ -30,9 +30,11 @@ class AssetCard extends StatelessWidget {
     end: Alignment.bottomRight,
   );
 
-  /// 翡翠渐变 - 用于盈利展示
-  static const emeraldGradient = LinearGradient(
-    colors: [AppColorScheme.darkTertiary, Color(0xFF7de8b8)],
+  /// 翡翠渐变 - 用于盈利展示（主题感知）
+  static LinearGradient getEmeraldGradient(bool isDark) => LinearGradient(
+    colors: isDark
+        ? [AppColorScheme.darkTertiary, const Color(0xFF7de8b8)]
+        : [AppColorScheme.lightTertiary, const Color(0xFF00c987)],
     begin: Alignment.topLeft,
     end: Alignment.bottomRight,
   );

flutter_monisuo/lib/ui/components/neon_glow.dart

@@ -214,7 +214,7 @@ class _NeonButtonState extends State<NeonButton>
       case NeonButtonType.secondary:
         return colorScheme.secondary;
       case NeonButtonType.tertiary:
-        return AppColorScheme.up;
+        return AppColorScheme.getUpColor(isDark);
       case NeonButtonType.error:
         return AppColorScheme.down;
       case NeonButtonType.outline:
@@ -250,7 +250,7 @@ class _NeonButtonState extends State<NeonButton>
       case NeonButtonType.secondary:
         return colorScheme.secondary.withOpacity(isDark ? 0.15 : 0.08);
       case NeonButtonType.tertiary:
-        return AppColorScheme.up.withOpacity(isDark ? 0.2 : 0.1);
+        return AppColorScheme.getUpBackgroundColor(isDark, opacity: isDark ? 0.2 : 0.1);
       case NeonButtonType.error:
         return AppColorScheme.down.withOpacity(0.3);
       case NeonButtonType.outline:
@@ -278,7 +278,7 @@ class _NeonButtonState extends State<NeonButton>
           end: const Alignment(0.7, 0.7),
         );
       case NeonButtonType.tertiary:
-        return AppColorScheme.buyGradient;
+        return AppColorScheme.getBuyGradient(isDark);
       case NeonButtonType.error:
         return AppColorScheme.sellGradient;
       default:

flutter_monisuo/lib/ui/pages/asset/asset_page.dart

@@ -406,6 +406,7 @@ class _HoldingItem extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
 
     return Padding(
       padding: EdgeInsets.symmetric(vertical: AppSpacing.sm),
@@ -464,7 +465,7 @@ class _HoldingItem extends StatelessWidget {
               Text(
                 holding.formattedProfitRate,
                 style: TextStyle(
-                  color: holding.isProfit ? AppColorScheme.up : AppColorScheme.down,
+                  color: holding.isProfit ? AppColorScheme.getUpColor(isDark) : AppColorScheme.down,
                   fontSize: 12,
                   fontWeight: FontWeight.w600,
                 ),
@@ -598,6 +599,7 @@ void _showDepositResultDialog(BuildContext context, Map<String, dynamic> data) {
   final walletAddress = data['walletAddress'] as String? ?? '';
   final walletNetwork = data['walletNetwork'] as String? ?? 'TRC20';
   final colorScheme = Theme.of(context).colorScheme;
+  final isDark = Theme.of(context).brightness == Brightness.dark;
 
   showShadDialog(
     context: context,
@@ -614,7 +616,7 @@ void _showDepositResultDialog(BuildContext context, Map<String, dynamic> data) {
               children: [
                 NeonIcon(
                   icon: Icons.check_circle,
-                  color: AppColorScheme.up,
+                  color: AppColorScheme.getUpColor(isDark),
                   size: 24,
                 ),
                 SizedBox(width: AppSpacing.sm),

flutter_monisuo/lib/ui/pages/home/home_page.dart

@@ -328,7 +328,7 @@ class _GlassBalanceCard extends StatelessWidget {
               Container(
                 padding: EdgeInsets.symmetric(horizontal: AppSpacing.sm, vertical: AppSpacing.xs),
                 decoration: BoxDecoration(
-                  color: AppColorScheme.up.withOpacity(0.1),
+                  color: AppColorScheme.getUpBackgroundColor(isDark, opacity: 0.1),
                   borderRadius: BorderRadius.circular(AppRadius.md),
                 ),
                 child: Row(
@@ -336,14 +336,14 @@ class _GlassBalanceCard extends StatelessWidget {
                   children: [
                     Icon(
                       LucideIcons.trendingUp,
-                      color: AppColorScheme.up,
+                      color: AppColorScheme.getUpColor(isDark),
                       size: 16,
                     ),
                     SizedBox(width: AppSpacing.xs),
                     Text(
                       '+0.00%',
                       style: TextStyle(
-                        color: AppColorScheme.up,
+                        color: AppColorScheme.getUpColor(isDark),
                         fontWeight: FontWeight.bold,
                         fontSize: 14,
                       ),
@@ -382,6 +382,7 @@ class _QuickActionsGrid extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
 
     return Row(
       mainAxisAlignment: MainAxisAlignment.spaceAround,
@@ -401,7 +402,7 @@ class _QuickActionsGrid extends StatelessWidget {
         _QuickActionBtn(
           icon: LucideIcons.arrowRightLeft,
           label: '划转',
-          color: AppColorScheme.up,
+          color: AppColorScheme.getUpColor(isDark),
           onTap: onTransfer,
         ),
         _QuickActionBtn(
@@ -627,14 +628,14 @@ class _EmptyHoldings extends StatelessWidget {
                     height: 40,
                     decoration: BoxDecoration(
                       shape: BoxShape.circle,
-                      color: AppColorScheme.up.withOpacity(0.2),
+                      color: AppColorScheme.getUpBackgroundColor(isDark, opacity: 0.2),
                       border: Border.all(
-                        color: AppColorScheme.up.withOpacity(0.3),
+                        color: AppColorScheme.getUpBackgroundColor(isDark, opacity: 0.3),
                       ),
                     ),
                     child: Icon(
                       LucideIcons.coins,
-                      color: AppColorScheme.up,
+                      color: AppColorScheme.getUpColor(isDark),
                       size: 20,
                     ),
                   ),
@@ -746,6 +747,7 @@ class _HoldingItem extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
 
     return Padding(
       padding: EdgeInsets.symmetric(vertical: AppSpacing.sm + AppSpacing.xs),
@@ -802,7 +804,7 @@ class _HoldingItem extends StatelessWidget {
               Text(
                 holding.formattedProfitRate,
                 style: TextStyle(
-                  color: holding.isProfit ? AppColorScheme.up : AppColorScheme.down,
+                  color: holding.isProfit ? AppColorScheme.getUpColor(isDark) : AppColorScheme.down,
                   fontSize: 12,
                   fontWeight: FontWeight.w500,
                 ),