优化：生成图片页面

lib/core/theme/app_colors.dart

@@ -6,6 +6,10 @@ abstract final class AppColors {
   static const Color primary = Color(0xFF8B5CF6);
   static const Color primaryLight = Color(0x338B5CF6); // #8B5CF620
   static const Color primaryShadow = Color(0x338B5CF6); // #8B5CF620 for shadow
+  /// 底栏选中、分辨率 chip 等：透出底层，字仍用 [surface] 可读
+  static Color get primaryGlass => primary.withValues(alpha: 0.58);
+  /// 生成页主按钮：略不透明，保证主操作仍醒目
+  static Color get primaryGlassEmphasis => primary.withValues(alpha: 0.72);
 
   // Neutrals
   static const Color background = Color(0xFFFAFAFA);

lib/features/generate_video/generate_video_screen.dart

@@ -215,44 +215,66 @@ class _GenerateVideoScreenState extends State<GenerateVideoScreen> {
 
   @override
   Widget build(BuildContext context) {
+    final topInset = MediaQuery.paddingOf(context).top;
+    final creditsDisplay =
+        UserCreditsData.of(context)?.creditsDisplay ?? '--';
+
     return Scaffold(
-      backgroundColor: AppColors.background,
+      extendBodyBehindAppBar: true,
+      backgroundColor: Colors.black,
       appBar: PreferredSize(
-        preferredSize: const Size.fromHeight(56),
+        preferredSize: Size.fromHeight(topInset + 56),
+        child: Container(
+          padding: EdgeInsets.only(top: topInset),
+          decoration: BoxDecoration(
+            gradient: LinearGradient(
+              begin: Alignment.topCenter,
+              end: Alignment.bottomCenter,
+              colors: [
+                Colors.black.withValues(alpha: 0.72),
+                Colors.black.withValues(alpha: 0.35),
+                Colors.black.withValues(alpha: 0.0),
+              ],
+              stops: const [0.0, 0.55, 1.0],
+            ),
+          ),
+          child: SizedBox(
+            height: 56,
             child: TopNavBar(
               title: 'Generate',
+              credits: creditsDisplay,
+              onCreditsTap: () => Navigator.of(context).pushNamed('/recharge'),
               showBackButton: true,
               onBack: () => Navigator.of(context).pop(),
+              backgroundColor: Colors.transparent,
+              foregroundColor: AppColors.surface,
             ),
           ),
-      body: Column(
+        ),
+      ),
+      body: Stack(
+        fit: StackFit.expand,
         children: [
-          Expanded(
+          _GenerateFullScreenBackground(
-            child: SingleChildScrollView(
-              padding: const EdgeInsets.fromLTRB(
-                AppSpacing.screenPaddingLarge,
-                AppSpacing.screenPaddingLarge,
-                AppSpacing.screenPaddingLarge,
-                AppSpacing.lg,
-              ),
-              child: Column(
-                crossAxisAlignment: CrossAxisAlignment.stretch,
-                children: [
-                  _CreditsCard(
-                    credits:
-                        UserCreditsData.of(context)?.creditsDisplay ?? '--',
-                  ),
-                  const SizedBox(height: AppSpacing.xxl),
-                  _VideoPreviewArea(
             videoUrl: widget.task?.previewVideoUrl,
             imageUrl: widget.task?.previewImageUrl,
           ),
+          Positioned.fill(
+            child: DecoratedBox(
+              decoration: BoxDecoration(
+                gradient: LinearGradient(
+                  begin: Alignment.topCenter,
+                  end: Alignment.bottomCenter,
+                  colors: [
+                    Colors.black.withValues(alpha: 0.12),
+                    Colors.black.withValues(alpha: 0.55),
                   ],
+                  stops: const [0.45, 1.0],
+                ),
               ),
             ),
           ),
           SafeArea(
-            top: false,
             child: Padding(
               padding: const EdgeInsets.fromLTRB(
                 AppSpacing.screenPaddingLarge,
@@ -261,13 +283,16 @@ class _GenerateVideoScreenState extends State<GenerateVideoScreen> {
                 AppSpacing.screenPaddingLarge,
               ),
               child: Column(
-                mainAxisSize: MainAxisSize.min,
                 crossAxisAlignment: CrossAxisAlignment.stretch,
                 children: [
+                  const Spacer(),
                   if (_hasVideo)
-                    _ResolutionToggle(
+                    Center(
+                      child: _ResolutionToggle(
                         selected: _selectedResolution,
-                      onChanged: (r) => setState(() => _selectedResolution = r),
+                        onChanged: (r) =>
+                            setState(() => _selectedResolution = r),
+                      ),
                     ),
                   if (_hasVideo) const SizedBox(height: AppSpacing.xxl),
                   _GenerateButton(
@@ -285,65 +310,9 @@ class _GenerateVideoScreenState extends State<GenerateVideoScreen> {
   }
 }
 
-class _CreditsCard extends StatelessWidget {
+/// 列表传入的预览图/视频：全屏背景层，超出视口 [BoxFit.cover] 裁切。
-  const _CreditsCard({required this.credits});
+class _GenerateFullScreenBackground extends StatefulWidget {
-
+  const _GenerateFullScreenBackground({
-  final String credits;
-
-  @override
-  Widget build(BuildContext context) {
-    return Container(
-      padding: const EdgeInsets.symmetric(
-        horizontal: AppSpacing.xxl,
-        vertical: AppSpacing.xl,
-      ),
-      decoration: BoxDecoration(
-        color: AppColors.primary,
-        borderRadius: BorderRadius.circular(16),
-        border: Border.all(
-          color: AppColors.primary.withValues(alpha: 0.5),
-        ),
-        boxShadow: [
-          BoxShadow(
-            color: AppColors.primaryShadow.withValues(alpha: 0.25),
-            blurRadius: 8,
-            offset: const Offset(0, 2),
-          ),
-        ],
-      ),
-      child: Row(
-        children: [
-          const Icon(LucideIcons.sparkles, size: 28, color: AppColors.surface),
-          const SizedBox(width: AppSpacing.md),
-          Column(
-            crossAxisAlignment: CrossAxisAlignment.start,
-            children: [
-              Text(
-                'Available Credits',
-                style: AppTypography.bodyRegular.copyWith(
-                  color: AppColors.surface.withValues(alpha: 0.8),
-                ),
-              ),
-              Text(
-                credits,
-                style: AppTypography.bodyLarge.copyWith(
-                  fontSize: 32,
-                  fontWeight: FontWeight.w700,
-                  color: AppColors.surface,
-                ),
-              ),
-            ],
-          ),
-        ],
-      ),
-    );
-  }
-}
-
-/// Video preview area - video URL from card click. Auto-load and play on init.
-/// Video fit: contain (no crop). Loading animation until ready.
-class _VideoPreviewArea extends StatefulWidget {
-  const _VideoPreviewArea({
     this.videoUrl,
     this.imageUrl,
   });
@@ -352,10 +321,12 @@ class _VideoPreviewArea extends StatefulWidget {
   final String? imageUrl;
 
   @override
-  State<_VideoPreviewArea> createState() => _VideoPreviewAreaState();
+  State<_GenerateFullScreenBackground> createState() =>
+      _GenerateFullScreenBackgroundState();
 }
 
-class _VideoPreviewAreaState extends State<_VideoPreviewArea> {
+class _GenerateFullScreenBackgroundState
+    extends State<_GenerateFullScreenBackground> {
   VideoPlayerController? _controller;
 
   @override
@@ -374,7 +345,7 @@ class _VideoPreviewAreaState extends State<_VideoPreviewArea> {
   }
 
   @override
-  void didUpdateWidget(covariant _VideoPreviewArea oldWidget) {
+  void didUpdateWidget(covariant _GenerateFullScreenBackground oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (oldWidget.videoUrl != widget.videoUrl) {
       _controller?.dispose();
@@ -394,11 +365,15 @@ class _VideoPreviewAreaState extends State<_VideoPreviewArea> {
     try {
       final file = await DefaultCacheManager().getSingleFile(url);
       if (!mounted) return;
-      final controller = VideoPlayerController.file(file);
+      final controller = VideoPlayerController.file(
+        file,
+        videoPlayerOptions: VideoPlayerOptions(mixWithOthers: true),
+      );
       await controller.initialize();
       if (!mounted) return;
+      await controller.setVolume(1.0);
+      await controller.setLooping(true);
       await controller.play();
-      controller.setLooping(true);
       if (mounted) {
         setState(() {
           _controller = controller;
@@ -416,206 +391,85 @@ class _VideoPreviewAreaState extends State<_VideoPreviewArea> {
     final hasVideo = widget.videoUrl != null && widget.videoUrl!.isNotEmpty;
     final hasImage = widget.imageUrl != null && widget.imageUrl!.isNotEmpty;
 
-    // 图片模式：宽度=组件宽度，高度按图片宽高比自适应
+    return Stack(
-    if (!hasVideo && hasImage) {
-      return LayoutBuilder(
-        builder: (context, constraints) {
-          return Container(
-            width: constraints.maxWidth,
-            decoration: BoxDecoration(
-              color: AppColors.surfaceAlt,
-              borderRadius: BorderRadius.circular(16),
-              border: Border.all(
-                color: AppColors.border,
-                width: 1,
-              ),
-            ),
-            clipBehavior: Clip.antiAlias,
-            child: _AspectRatioImage(
-              imageUrl: widget.imageUrl!,
-              maxWidth: constraints.maxWidth,
-            ),
-          );
-        },
-      );
-    }
-
-    // 视频模式：aspect ratio 来自视频或 16:9 占位
-    final aspectRatio = isReady &&
-            _controller!.value.size.width > 0 &&
-            _controller!.value.size.height > 0
-        ? _controller!.value.size.width / _controller!.value.size.height
-        : 16 / 9;
-
-    return LayoutBuilder(
-      builder: (context, constraints) {
-        final width = constraints.maxWidth;
-        final height = width / aspectRatio;
-
-        return Container(
-          width: width,
-          height: height,
-          decoration: BoxDecoration(
-            color: AppColors.surfaceAlt,
-            borderRadius: BorderRadius.circular(16),
-            border: Border.all(
-              color: AppColors.border,
-              width: 1,
-            ),
-          ),
-          clipBehavior: Clip.antiAlias,
-          child: Stack(
       fit: StackFit.expand,
-            alignment: Alignment.center,
       children: [
-              if (isReady)
+        if (!hasVideo && hasImage)
-                SizedBox.expand(
+          Positioned.fill(
+            child: CachedNetworkImage(
+              imageUrl: widget.imageUrl!,
+              fit: BoxFit.cover,
+              width: double.infinity,
+              height: double.infinity,
+              placeholder: (_, __) => const _BgLoadingPlaceholder(),
+              errorWidget: (_, __, ___) => const _BgErrorPlaceholder(),
+            ),
+          )
+        else if (hasVideo && isReady)
+          Positioned.fill(
+            child: ClipRect(
               child: FittedBox(
-                    fit: BoxFit.contain,
+                fit: BoxFit.cover,
                 child: SizedBox(
                   width: _controller!.value.size.width,
                   height: _controller!.value.size.height,
                   child: VideoPlayer(_controller!),
                 ),
               ),
+            ),
           )
-              else if (hasImage)
+        else if (hasVideo && hasImage)
-                CachedNetworkImage(
+          Positioned.fill(
+            child: CachedNetworkImage(
               imageUrl: widget.imageUrl!,
-                  fit: BoxFit.contain,
+              fit: BoxFit.cover,
               width: double.infinity,
               height: double.infinity,
-                  placeholder: (_, __) =>
+              placeholder: (_, __) => const _BgLoadingPlaceholder(),
-                      const _LoadingOverlay(isLoading: true),
+              errorWidget: (_, __, ___) => const _BgErrorPlaceholder(),
-                  errorWidget: (_, __, ___) =>
+            ),
-                      const _LoadingOverlay(isLoading: false),
           )
+        else if (hasVideo)
+          const Positioned.fill(child: _BgLoadingPlaceholder())
         else
-                const _LoadingOverlay(isLoading: false),
+          const Positioned.fill(child: _BgErrorPlaceholder()),
-              if (hasVideo && !isReady)
-                const Positioned.fill(
-                  child: _LoadingOverlay(isLoading: true),
-                ),
       ],
-          ),
-        );
-      },
     );
   }
 }
 
-/// 图片展示：宽度=组件宽度，高度按图片宽高比自适应
+class _BgLoadingPlaceholder extends StatelessWidget {
-class _AspectRatioImage extends StatefulWidget {
+  const _BgLoadingPlaceholder();
-  const _AspectRatioImage({
-    required this.imageUrl,
-    required this.maxWidth,
-  });
-
-  final String imageUrl;
-  final double maxWidth;
-
-  @override
-  State<_AspectRatioImage> createState() => _AspectRatioImageState();
-}
-
-class _AspectRatioImageState extends State<_AspectRatioImage> {
-  double? _aspectRatio;
-  ImageStream? _stream;
-  late ImageStreamListener _listener;
-
-  @override
-  void initState() {
-    super.initState();
-    _listener = ImageStreamListener(_onImageLoaded, onError: _onImageError);
-    _resolveImage();
-  }
-
-  @override
-  void didUpdateWidget(covariant _AspectRatioImage oldWidget) {
-    super.didUpdateWidget(oldWidget);
-    if (oldWidget.imageUrl != widget.imageUrl) {
-      _stream?.removeListener(_listener);
-      _aspectRatio = null;
-      _resolveImage();
-    }
-  }
-
-  void _resolveImage() {
-    final provider = CachedNetworkImageProvider(widget.imageUrl);
-    _stream = provider.resolve(const ImageConfiguration());
-    _stream!.addListener(_listener);
-  }
-
-  void _onImageLoaded(ImageInfo info, bool sync) {
-    if (!mounted) return;
-    final w = info.image.width.toDouble();
-    final h = info.image.height.toDouble();
-    if (w > 0 && h > 0) {
-      setState(() => _aspectRatio = w / h);
-    }
-  }
-
-  void _onImageError(dynamic exception, StackTrace? stackTrace) {
-    if (mounted) setState(() => _aspectRatio = 1);
-  }
-
-  @override
-  void dispose() {
-    _stream?.removeListener(_listener);
-    super.dispose();
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    final ratio = _aspectRatio ?? 1;
-    final height = widget.maxWidth / ratio;
-
-    return SizedBox(
-      width: widget.maxWidth,
-      height: height,
-      child: CachedNetworkImage(
-        imageUrl: widget.imageUrl,
-        fit: BoxFit.contain,
-        width: widget.maxWidth,
-        height: height,
-        placeholder: (_, __) => SizedBox(
-          width: widget.maxWidth,
-          height: widget.maxWidth,
-          child: const _LoadingOverlay(isLoading: true),
-        ),
-        errorWidget: (_, __, ___) => SizedBox(
-          width: widget.maxWidth,
-          height: widget.maxWidth,
-          child: const _LoadingOverlay(isLoading: false),
-        ),
-      ),
-    );
-  }
-}
-
-class _LoadingOverlay extends StatelessWidget {
-  const _LoadingOverlay({this.isLoading = true});
-
-  final bool isLoading;
 
   @override
   Widget build(BuildContext context) {
     return Container(
-      color: AppColors.surfaceAlt,
+      color: AppColors.textPrimary,
       alignment: Alignment.center,
-      child: isLoading
+      child: const SizedBox(
-          ? const SizedBox(
         width: 40,
         height: 40,
         child: CircularProgressIndicator(
           strokeWidth: 2,
-                color: AppColors.primary,
+          color: AppColors.surface,
         ),
-            )
+      ),
-          : const Icon(
+    );
-              LucideIcons.video,
+  }
-              size: 48,
+}
-              color: AppColors.textMuted,
+
+class _BgErrorPlaceholder extends StatelessWidget {
+  const _BgErrorPlaceholder();
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      color: AppColors.textPrimary,
+      alignment: Alignment.center,
+      child: Icon(
+        LucideIcons.image_off,
+        size: 56,
+        color: AppColors.surface.withValues(alpha: 0.45),
       ),
     );
   }
@@ -644,7 +498,7 @@ class _ResolutionToggle extends StatelessWidget {
             'Resolution',
             style: AppTypography.bodyMedium.copyWith(
               fontSize: 14,
-              color: AppColors.textPrimary,
+              color: AppColors.surface,
               fontWeight: FontWeight.w600,
             ),
           ),
@@ -685,14 +539,22 @@ class _ResolutionOption extends StatelessWidget {
         height: 36,
         padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
         decoration: BoxDecoration(
-          color: isSelected ? AppColors.primary : AppColors.surfaceAlt,
+          color: isSelected
+              ? AppColors.primaryGlass
+              : AppColors.surface.withValues(alpha: 0.18),
           borderRadius: BorderRadius.circular(18),
-          border:
+          border: isSelected
-              isSelected ? null : Border.all(color: AppColors.border, width: 1),
+              ? Border.all(
+                  color: AppColors.primary.withValues(alpha: 0.42),
+                  width: 1)
+              : Border.all(
+                  color: AppColors.surface.withValues(alpha: 0.45),
+                  width: 1,
+                ),
           boxShadow: isSelected
               ? [
                   BoxShadow(
-                    color: AppColors.primaryShadow.withValues(alpha: 0.19),
+                    color: AppColors.primaryShadow.withValues(alpha: 0.22),
                     blurRadius: 4,
                     offset: const Offset(0, 2),
                   ),
@@ -704,7 +566,9 @@ class _ResolutionOption extends StatelessWidget {
           label,
           style: AppTypography.bodyMedium.copyWith(
             fontSize: 13,
-            color: isSelected ? AppColors.surface : AppColors.textSecondary,
+            color: isSelected
+                ? AppColors.surface
+                : AppColors.surface.withValues(alpha: 0.85),
             fontWeight: isSelected ? FontWeight.w600 : FontWeight.w500,
           ),
         ),
@@ -733,11 +597,15 @@ class _GenerateButton extends StatelessWidget {
         child: Container(
           height: 56,
           decoration: BoxDecoration(
-            color: AppColors.primary,
+            color: AppColors.primaryGlassEmphasis,
             borderRadius: BorderRadius.circular(16),
+            border: Border.all(
+              color: AppColors.primary.withValues(alpha: 0.45),
+              width: 1,
+            ),
             boxShadow: [
               BoxShadow(
-                color: AppColors.primaryShadow.withValues(alpha: 0.25),
+                color: AppColors.primaryShadow.withValues(alpha: 0.28),
                 blurRadius: 8,
                 offset: const Offset(0, 2),
               ),

lib/shared/widgets/credits_badge.dart

@@ -10,13 +10,23 @@ class CreditsBadge extends StatelessWidget {
     super.key,
     required this.credits,
     this.onTap,
+    this.foregroundColor,
+    this.capsuleColor,
   });
 
   final String credits;
   final VoidCallback? onTap;
+  /// 图标与数字颜色；默认 [AppColors.primary]
+  final Color? foregroundColor;
+  /// 胶囊背景；默认 [AppColors.primaryLight]
+  final Color? capsuleColor;
 
   @override
   Widget build(BuildContext context) {
+    final fg = foregroundColor ?? AppColors.primary;
+    final capsule = capsuleColor ?? AppColors.primaryLight;
+    final lightOnDarkNav = foregroundColor != null;
+
     return GestureDetector(
       onTap: onTap,
       child: Container(
@@ -25,9 +35,17 @@ class CreditsBadge extends StatelessWidget {
           vertical: AppSpacing.sm,
         ),
         decoration: BoxDecoration(
-          color: AppColors.primaryLight,
+          color: capsule,
           borderRadius: BorderRadius.circular(14),
-          boxShadow: [
+          boxShadow: lightOnDarkNav
+              ? [
+                  BoxShadow(
+                    color: Colors.black.withValues(alpha: 0.28),
+                    blurRadius: 6,
+                    offset: const Offset(0, 2),
+                  ),
+                ]
+              : [
                   BoxShadow(
                     color: AppColors.primaryShadow.withValues(alpha: 0.13),
                     blurRadius: 6,
@@ -38,15 +56,14 @@ class CreditsBadge extends StatelessWidget {
         child: Row(
           mainAxisSize: MainAxisSize.min,
           children: [
-            const Icon(LucideIcons.sparkles,
+            Icon(LucideIcons.sparkles, size: 16, color: fg),
-                size: 16, color: AppColors.primary),
             const SizedBox(width: AppSpacing.sm),
             Text(
               credits,
               style: AppTypography.bodyRegular.copyWith(
                 fontSize: 14,
                 fontWeight: FontWeight.w600,
-                color: AppColors.primary,
+                color: fg,
               ),
             ),
           ],

lib/shared/widgets/top_nav_bar.dart

@@ -14,6 +14,8 @@ class TopNavBar extends StatelessWidget implements PreferredSizeWidget {
     this.showBackButton = false,
     this.onBack,
     this.onCreditsTap,
+    this.backgroundColor = AppColors.surface,
+    this.foregroundColor,
   });
 
   final String title;
@@ -21,18 +23,29 @@ class TopNavBar extends StatelessWidget implements PreferredSizeWidget {
   final bool showBackButton;
   final VoidCallback? onBack;
   final VoidCallback? onCreditsTap;
+  /// 例如全屏背景页上叠半透明导航栏时用 [Colors.transparent]
+  final Color backgroundColor;
+  /// 标题与返回键颜色；默认 [AppColors.textPrimary]
+  final Color? foregroundColor;
 
   @override
   Size get preferredSize => const Size.fromHeight(56);
 
   @override
   Widget build(BuildContext context) {
+    final fg = foregroundColor ?? AppColors.textPrimary;
+    final titleStyle = foregroundColor != null
+        ? AppTypography.navTitle.copyWith(color: foregroundColor)
+        : AppTypography.navTitle;
+
     return Container(
       height: 56,
       padding: const EdgeInsets.symmetric(horizontal: AppSpacing.screenPadding),
-      decoration: const BoxDecoration(
+      decoration: BoxDecoration(
-        color: AppColors.surface,
+        color: backgroundColor,
-        boxShadow: [
+        boxShadow: backgroundColor.a < 0.02
+            ? null
+            : const [
                 BoxShadow(
                   color: AppColors.shadowLight,
                   blurRadius: 8,
@@ -46,14 +59,14 @@ class TopNavBar extends StatelessWidget implements PreferredSizeWidget {
             GestureDetector(
               onTap: onBack ?? () => Navigator.of(context).pop(),
               behavior: HitTestBehavior.opaque,
-              child: const SizedBox(
+              child: SizedBox(
                 width: 40,
                 height: 40,
                 child: Center(
                   child: Icon(
                     LucideIcons.arrow_left,
                     size: 24,
-                    color: AppColors.textPrimary,
+                    color: fg,
                   ),
                 ),
               ),
@@ -63,19 +76,25 @@ class TopNavBar extends StatelessWidget implements PreferredSizeWidget {
                 ? Center(
                     child: Text(
                       title,
-                      style: AppTypography.navTitle,
+                      style: titleStyle,
                     ),
                   )
                 : Align(
                     alignment: Alignment.centerLeft,
                     child: Text(
                       title,
-                      style: AppTypography.navTitle,
+                      style: titleStyle,
                     ),
                   ),
           ),
           if (credits != null)
-            CreditsBadge(credits: credits!, onTap: onCreditsTap)
+            CreditsBadge(
+              credits: credits!,
+              onTap: onCreditsTap,
+              foregroundColor: foregroundColor,
+              capsuleColor:
+                  foregroundColor?.withValues(alpha: 0.22),
+            )
           else
             const SizedBox(width: 40),
         ],