style: 完成前端专业金融风格优化

- 主题配色: 黑金传奇(暗) + 白金殿堂(亮)
- 底部导航: 去掉毛玻璃，简洁专业
- 交易页面: 明亮模式颜色优化，实心按钮
- 按钮圆角: xxl(24px) → lg(12px)/md(8px)
- 字体系统: Inter(币安同款)
- 整体风格: 专业金融科技

flutter_monisuo/lib/ui/pages/trade/trade_page.dart

@@ -265,6 +265,7 @@ class _TradePageState extends State<TradePage>
 
   void _showResultDialog(bool success, String title, String message) {
     final colorScheme = Theme.of(context).colorScheme;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
     showShadDialog(
       context: context,
       builder: (ctx) => ShadDialog.alert(
@@ -272,7 +273,9 @@ class _TradePageState extends State<TradePage>
           children: [
             NeonIcon(
               icon: success ? Icons.check_circle : Icons.error,
-              color: success ? AppColorScheme.up : colorScheme.error,
+              color: success
+                  ? AppColorScheme.getUpColor(isDark)
+                  : colorScheme.error,
               size: 24,
             ),
             SizedBox(width: AppSpacing.sm),
@@ -310,12 +313,15 @@ class _ConfirmDialog extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
-    final actionColor = isBuy ? AppColorScheme.up : AppColorScheme.down;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
+    final actionColor = isBuy
+        ? AppColorScheme.getUpColor(isDark)
+        : AppColorScheme.getDownColor(isDark);
 
     return Dialog(
       backgroundColor: Colors.transparent,
       child: GlassPanel(
-        borderRadius: BorderRadius.circular(AppRadius.xxl),
+        borderRadius: BorderRadius.circular(AppRadius.lg),
         padding: EdgeInsets.all(AppSpacing.lg),
         child: Column(
           mainAxisSize: MainAxisSize.min,
@@ -510,8 +516,11 @@ class _CoinSelector extends StatelessWidget {
   Widget _buildCoinItem(
       Coin coin, BuildContext context, BuildContext sheetContext) {
     final colorScheme = Theme.of(context).colorScheme;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
     final isSelected = selectedCoin?.code == coin.code;
-    final changeColor = coin.isUp ? AppColorScheme.up : AppColorScheme.down;
+    final changeColor = coin.isUp
+        ? AppColorScheme.getUpColor(isDark)
+        : AppColorScheme.getDownColor(isDark);
 
     return GestureDetector(
       onTap: () {
@@ -762,8 +771,11 @@ class _TradeFormCard extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
+    final isDark = Theme.of(context).brightness == Brightness.dark;
     final isBuy = tradeType == 0;
-    final actionColor = isBuy ? AppColorScheme.up : AppColorScheme.down;
+    final actionColor = isBuy
+        ? AppColorScheme.getUpColor(isDark)
+        : AppColorScheme.getDownColor(isDark);
 
     return GlassPanel(
       padding: EdgeInsets.all(AppSpacing.lg),
@@ -784,7 +796,7 @@ class _TradeFormCard extends StatelessWidget {
                     context: context,
                     label: '买入',
                     isActive: isBuy,
-                    color: AppColorScheme.up,
+                    color: AppColorScheme.buyButtonFill,
                     icon: LucideIcons.trendingUp,
                     onTap: () => onTradeTypeChanged(0),
                   ),
@@ -795,7 +807,7 @@ class _TradeFormCard extends StatelessWidget {
                     context: context,
                     label: '卖出',
                     isActive: !isBuy,
-                    color: AppColorScheme.down,
+                    color: AppColorScheme.sellButtonFill,
                     icon: LucideIcons.trendingDown,
                     onTap: () => onTradeTypeChanged(1),
                   ),
@@ -919,7 +931,7 @@ class _TradeFormCard extends StatelessWidget {
     );
   }
 
-  /// 买入/卖出切换按钮 - 实心填充 + 图标 + 光效
+  /// 买入/卖出切换按钮 - 实心填充 + 图标
   Widget _buildTypeButton({
     required BuildContext context,
     required String label,
@@ -937,15 +949,6 @@ class _TradeFormCard extends StatelessWidget {
         decoration: BoxDecoration(
           color: isActive ? color : Colors.transparent,
           borderRadius: BorderRadius.circular(AppRadius.lg),
-          boxShadow: isActive
-              ? [
-                  BoxShadow(
-                    color: color.withOpacity(0.35),
-                    blurRadius: 16,
-                    offset: const Offset(0, 4),
-                  ),
-                ]
-              : null,
         ),
         child: Row(
           mainAxisAlignment: MainAxisAlignment.center,
@@ -1015,11 +1018,8 @@ class _TradeButton extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final colorScheme = Theme.of(context).colorScheme;
-    final isDark = Theme.of(context).brightness == Brightness.dark;
-    final actionColor = isBuy ? AppColorScheme.up : AppColorScheme.down;
-    final gradient = isBuy
-        ? AppColorScheme.getBuyGradient(isDark)
-        : AppColorScheme.sellGradient;
+    final fillColor =
+        isBuy ? AppColorScheme.buyButtonFill : AppColorScheme.sellButtonFill;
 
     return GestureDetector(
       onTap: enabled ? onPressed : null,
@@ -1027,29 +1027,17 @@ class _TradeButton extends StatelessWidget {
         duration: const Duration(milliseconds: 200),
         height: 52,
         decoration: BoxDecoration(
-          gradient: enabled ? gradient : null,
-          color: enabled ? null : colorScheme.onSurface.withOpacity(0.08),
-          borderRadius: BorderRadius.circular(AppRadius.xxl),
-          boxShadow: enabled
-              ? [
-                  BoxShadow(
-                    color: actionColor.withOpacity(isDark ? 0.25 : 0.15),
-                    blurRadius: 20,
-                    offset: const Offset(0, 4),
-                  ),
-                ]
-              : null,
+          color: enabled ? fillColor : colorScheme.onSurface.withOpacity(0.08),
+          borderRadius: BorderRadius.circular(AppRadius.lg),
         ),
         child: Center(
           child: isLoading
-              ? SizedBox(
+              ? const SizedBox(
                   width: 20,
                   height: 20,
                   child: CircularProgressIndicator(
                     strokeWidth: 2,
-                    color: isBuy
-                        ? AppColorScheme.darkOnTertiary
-                        : Colors.white,
+                    color: Colors.white,
                   ),
                 )
               : Row(
@@ -1059,9 +1047,7 @@ class _TradeButton extends StatelessWidget {
                       isBuy ? LucideIcons.trendingUp : LucideIcons.trendingDown,
                       size: 16,
                       color: enabled
-                          ? (isBuy
-                              ? AppColorScheme.darkOnTertiary
-                              : Colors.white)
+                          ? Colors.white
                           : colorScheme.onSurface.withOpacity(0.3),
                     ),
                     SizedBox(width: AppSpacing.xs),
@@ -1071,9 +1057,7 @@ class _TradeButton extends StatelessWidget {
                         fontSize: 16,
                         fontWeight: FontWeight.w700,
                         color: enabled
-                            ? (isBuy
-                                ? AppColorScheme.darkOnTertiary
-                                : Colors.white)
+                            ? Colors.white
                             : colorScheme.onSurface.withOpacity(0.3),
                         letterSpacing: 0.5,
                       ),