src/NexusReader.Application/Abstractions/Services/IEpubExtractor.cs

@@ -0,0 +1,17 @@
+using FluentResults;
+
+namespace NexusReader.Application.Abstractions.Services;
+
+/// <summary>
+/// Service abstraction to extract raw text content from EPUB chapters.
+/// </summary>
+public interface IEpubExtractor
+{
+    /// <summary>
+    /// Extracts the sanitized, plain-text content of each chapter in the EPUB file.
+    /// </summary>
+    /// <param name="relativePath">The relative storage path of the EPUB file.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A list of plain-text chapters, or a failure result.</returns>
+    Task<Result<List<string>>> ExtractChaptersTextAsync(string relativePath, CancellationToken cancellationToken = default);
+}

src/NexusReader.Application/Abstractions/Services/IIdentityService.cs

@@ -11,4 +11,5 @@ public interface IIdentityService
     Task<Result> LogoutAsync();
     Task<Result<UserProfileDto>> GetProfileAsync();
     Task<Result> RefreshTokenAsync();
+    void ClearCache();
 }

src/NexusReader.Application/Commands/Library/IngestEbookCommandHandler.cs

@@ -1,5 +1,6 @@
 using FluentResults;
 using MediatR;
+using Microsoft.Extensions.DependencyInjection;
 using NexusReader.Application.Abstractions.Messaging;
 using NexusReader.Application.Abstractions.Persistence;
 using NexusReader.Application.Abstractions.Services;
@@ -11,13 +12,16 @@ public class IngestEbookCommandHandler : IRequestHandler<IngestEbookCommand, Res
 {
     private readonly IEbookRepository _ebookRepository;
     private readonly IBookStorageService _storageService;
+    private readonly IServiceScopeFactory _scopeFactory;
 
     public IngestEbookCommandHandler(
         IEbookRepository ebookRepository,
-        IBookStorageService storageService)
+        IBookStorageService storageService,
+        IServiceScopeFactory scopeFactory)
     {
         _ebookRepository = ebookRepository;
         _storageService = storageService;
+        _scopeFactory = scopeFactory;
     }
 
     public async Task<Result<Guid>> Handle(IngestEbookCommand request, CancellationToken cancellationToken)
@@ -72,6 +76,21 @@ public class IngestEbookCommandHandler : IRequestHandler<IngestEbookCommand, Res
             _ebookRepository.AddEbook(ebook);
             await _ebookRepository.SaveChangesAsync(cancellationToken);
 
+            // 4. Trigger asynchronous background processing and vector indexing
+            _ = Task.Run(async () =>
+            {
+                try
+                {
+                    using var scope = _scopeFactory.CreateScope();
+                    var mediator = scope.ServiceProvider.GetRequiredService<IMediator>();
+                    await mediator.Send(new ProcessEbookCommand(ebook.Id, request.UserId, request.TenantId));
+                }
+                catch (Exception)
+                {
+                    // Swallowed to prevent ThreadPool crashes
+                }
+            });
+
             return Result.Ok(ebook.Id);
         }
         catch (Exception ex)

src/NexusReader.Application/Commands/Library/ProcessEbookCommand.cs

@@ -0,0 +1,177 @@
+using System.Text.RegularExpressions;
+using FluentResults;
+using MediatR;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using NexusReader.Application.Abstractions.Messaging;
+using NexusReader.Application.Abstractions.Services;
+using NexusReader.Data.Persistence;
+
+namespace NexusReader.Application.Commands.Library;
+
+public record ProcessEbookCommand(
+    Guid EbookId,
+    string UserId,
+    string TenantId
+) : ICommand<bool>;
+
+public class ProcessEbookCommandHandler : IRequestHandler<ProcessEbookCommand, Result<bool>>
+{
+    private readonly IDbContextFactory<AppDbContext> _dbContextFactory;
+    private readonly IKnowledgeService _knowledgeService;
+    private readonly IEpubExtractor _epubExtractor;
+    private readonly ISyncBroadcaster _broadcaster;
+    private readonly ILogger<ProcessEbookCommandHandler> _logger;
+
+    public ProcessEbookCommandHandler(
+        IDbContextFactory<AppDbContext> dbContextFactory,
+        IKnowledgeService knowledgeService,
+        IEpubExtractor epubExtractor,
+        ISyncBroadcaster broadcaster,
+        ILogger<ProcessEbookCommandHandler> logger)
+    {
+        _dbContextFactory = dbContextFactory;
+        _knowledgeService = knowledgeService;
+        _epubExtractor = epubExtractor;
+        _broadcaster = broadcaster;
+        _logger = logger;
+    }
+
+    public async Task<Result<bool>> Handle(ProcessEbookCommand request, CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("[ProcessEbook] Starting background processing for Ebook: {EbookId}", request.EbookId);
+        
+        try
+        {
+            await _broadcaster.BroadcastIngestionProgressAsync(request.UserId, "Wyszukiwanie e-booka w bazie danych...", 0.05, cancellationToken);
+
+            using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+            var ebook = await dbContext.Ebooks.FindAsync(new object[] { request.EbookId }, cancellationToken);
+            if (ebook == null)
+            {
+                _logger.LogError("[ProcessEbook] Ebook not found in database: {EbookId}", request.EbookId);
+                return Result.Fail<bool>($"Ebook nie znaleziony w bazie danych: {request.EbookId}");
+            }
+
+            _logger.LogInformation("[ProcessEbook] Extracting chapters text for Ebook: {Title} ({FilePath})", ebook.Title, ebook.FilePath);
+            await _broadcaster.BroadcastIngestionProgressAsync(request.UserId, "Otwieranie i parsowanie pliku EPUB...", 0.1, cancellationToken);
+            
+            var extractionResult = await _epubExtractor.ExtractChaptersTextAsync(ebook.FilePath, cancellationToken);
+            if (extractionResult.IsFailed)
+            {
+                var errorMsg = extractionResult.Errors.FirstOrDefault()?.Message ?? "Failed to extract text chapters.";
+                _logger.LogError("[ProcessEbook] Extraction failed: {Error}", errorMsg);
+                return Result.Fail<bool>(extractionResult.Errors);
+            }
+
+            var chapters = extractionResult.Value;
+            if (chapters == null || !chapters.Any())
+            {
+                _logger.LogWarning("[ProcessEbook] EPUB has no readable content files: {EbookId}", request.EbookId);
+                return Result.Fail<bool>("EPUB nie zawiera czytelnych rozdziałów.");
+            }
+
+            int totalChapters = chapters.Count;
+            _logger.LogInformation("[ProcessEbook] Processing {Count} chapters for Ebook: {Title}", totalChapters, ebook.Title);
+            
+            await _broadcaster.BroadcastIngestionProgressAsync(request.UserId, $"Analizowanie struktury ({totalChapters} rozdziałów)...", 0.15, cancellationToken);
+
+            int processedChapters = 0;
+
+            for (int i = 0; i < totalChapters; i++)
+            {
+                var cleanText = chapters[i];
+
+                if (cleanText.Length < 100)
+                {
+                    _logger.LogInformation("[ProcessEbook] Skipping chapter {Index} (text too short: {Length} chars)", i, cleanText.Length);
+                    processedChapters++;
+                    continue;
+                }
+
+                // Chunk the text to maintain granular Knowledge Units
+                var chunks = ChunkText(cleanText, 3000);
+                _logger.LogInformation("[ProcessEbook] Chapter {Index} split into {ChunkCount} chunk(s)", i, chunks.Count);
+
+                foreach (var chunk in chunks)
+                {
+                    try
+                    {
+                        // Invoke GetKnowledgeMapAsync to extract, embed, and upsert knowledge units
+                        var result = await _knowledgeService.GetKnowledgeMapAsync(chunk, request.TenantId, request.EbookId, cancellationToken);
+                        if (result.IsFailed)
+                        {
+                            _logger.LogWarning("[ProcessEbook] Failed to generate knowledge map for a chunk of chapter {Index}: {Error}", i, result.Errors.FirstOrDefault()?.Message);
+                        }
+                    }
+                    catch (Exception ex)
+                    {
+                        _logger.LogError(ex, "[ProcessEbook] Exception during AI vectorization of chapter {Index} chunk", i);
+                    }
+                }
+
+                processedChapters++;
+                double progress = 0.15 + (0.75 * processedChapters / totalChapters);
+                await _broadcaster.BroadcastIngestionProgressAsync(
+                    request.UserId, 
+                    $"Przetwarzanie rozdziału {processedChapters} z {totalChapters} przez AI...", 
+                    progress, 
+                    cancellationToken);
+            }
+
+            // Mark the ebook as ready
+            ebook.IsReadyForReading = true;
+            await dbContext.SaveChangesAsync(cancellationToken);
+
+            _logger.LogInformation("[ProcessEbook] Ingestion and vector indexing completed for: {Title}", ebook.Title);
+            
+            await _broadcaster.BroadcastIngestionProgressAsync(
+                request.UserId, 
+                "Indeksowanie wektorowe e-booka przez Nexus AI zakończone pomyślnie!", 
+                1.0, 
+                cancellationToken);
+
+            return Result.Ok(true);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "[ProcessEbook] Critical error during background EPUB vectorization of ebook {EbookId}", request.EbookId);
+            await _broadcaster.BroadcastIngestionProgressAsync(
+                request.UserId, 
+                $"Błąd indeksowania: {ex.Message}", 
+                1.0, 
+                cancellationToken);
+            return Result.Fail<bool>(new Error("Wystąpił błąd podczas indeksowania e-booka przez AI").CausedBy(ex));
+        }
+    }
+
+    private static List<string> ChunkText(string text, int maxWords = 3000)
+    {
+        var words = text.Split(' ', StringSplitOptions.RemoveEmptyEntries);
+        var chunks = new List<string>();
+        if (words.Length <= maxWords)
+        {
+            chunks.Add(text);
+            return chunks;
+        }
+        var currentChunk = new List<string>();
+        int count = 0;
+        foreach (var word in words)
+        {
+            currentChunk.Add(word);
+            count++;
+            if (count >= maxWords)
+            {
+                chunks.Add(string.Join(" ", currentChunk));
+                currentChunk.Clear();
+                count = 0;
+            }
+        }
+        if (currentChunk.Any())
+        {
+            chunks.Add(string.Join(" ", currentChunk));
+        }
+        return chunks;
+    }
+}

src/NexusReader.Application/Commands/Quiz/SubmitQuizResultCommand.cs

@@ -0,0 +1,10 @@
+using FluentResults;
+using NexusReader.Application.Abstractions.Messaging;
+
+namespace NexusReader.Application.Commands.Quiz;
+
+public record SubmitQuizResultCommand(
+    string UserId,
+    string Topic,
+    int Score,
+    int TotalQuestions) : ICommand;

src/NexusReader.Application/Commands/Quiz/SubmitQuizResultCommandHandler.cs

@@ -0,0 +1,44 @@
+using FluentResults;
+using Microsoft.EntityFrameworkCore;
+using NexusReader.Application.Abstractions.Messaging;
+using NexusReader.Data.Persistence;
+using NexusReader.Domain.Entities;
+
+namespace NexusReader.Application.Commands.Quiz;
+
+public sealed class SubmitQuizResultCommandHandler : ICommandHandler<SubmitQuizResultCommand>
+{
+    private readonly IDbContextFactory<AppDbContext> _dbContextFactory;
+
+    public SubmitQuizResultCommandHandler(IDbContextFactory<AppDbContext> dbContextFactory)
+    {
+        _dbContextFactory = dbContextFactory;
+    }
+
+    public async Task<Result> Handle(SubmitQuizResultCommand request, CancellationToken cancellationToken)
+    {
+        using var context = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        var user = await context.Users.FirstOrDefaultAsync(u => u.Id == request.UserId, cancellationToken);
+        if (user == null)
+        {
+            return Result.Fail("User not found.");
+        }
+
+        var quizResult = new QuizResult
+        {
+            Id = Guid.NewGuid(),
+            UserId = request.UserId,
+            TenantId = string.IsNullOrEmpty(user.TenantId) ? "global" : user.TenantId,
+            Topic = request.Topic,
+            Score = request.Score,
+            TotalQuestions = request.TotalQuestions,
+            CompletedDate = DateTime.UtcNow
+        };
+
+        context.QuizResults.Add(quizResult);
+        await context.SaveChangesAsync(cancellationToken);
+
+        return Result.Ok();
+    }
+}

src/NexusReader.Application/DTOs/AI/GroundedResponseDto.cs

@@ -13,4 +13,6 @@ public class CitationDto
     public string CitationId { get; set; } = string.Empty; // e.g., chunk hash/ID
     public string Snippet { get; set; } = string.Empty;    // Verified text snippet from context
     public string SourceBook { get; set; } = string.Empty; // Book title or description
+    public string? Author { get; set; }
+    public int? PageNumber { get; set; }
 }

src/NexusReader.Application/DTOs/User/UserProfileDto.cs

@@ -5,6 +5,7 @@ namespace NexusReader.Application.DTOs.User;
 public record UserProfileDto
 {
     public string Email { get; init; } = string.Empty;
+    public string UserId { get; init; } = string.Empty;
     public int AITokensUsed { get; init; }
     public Guid TenantId { get; init; }
     
@@ -15,11 +16,12 @@ public record UserProfileDto
 
     public int AverageQuizScore { get; init; }
     
-    /// <summary>
-    /// Summary of the last read book.
-    /// </summary>
+    public string? DisplayName { get; init; }
+    public int BooksReadCount { get; init; }
+    public int ConceptsMappedCount { get; init; }
     public LastReadBookDto? LastReadBook { get; init; }
-
+    public IReadOnlyList<QuizResultDto> RecentQuizzes { get; init; } = Array.Empty<QuizResultDto>();
+    public IReadOnlyList<MappedConceptDto> MappedConcepts { get; init; } = Array.Empty<MappedConceptDto>();
     public string[] Roles { get; init; } = Array.Empty<string>();
 
     // Helper properties for UI compatibility
@@ -28,6 +30,14 @@ public record UserProfileDto
     public string LastReadBookTitle => LastReadBook?.Title ?? PlanConstants.DefaultActivityLabel;
 }
 
+public record MappedConceptDto
+{
+    public string Id { get; init; } = string.Empty;
+    public string Type { get; init; } = string.Empty;
+    public string Content { get; init; } = string.Empty;
+    public string DisplayLabel => Content.Length > 25 ? Content.Substring(0, 22) + "..." : Content;
+}
+
 public record LastReadBookDto
 {
     public Guid Id { get; init; }
@@ -38,4 +48,15 @@ public record LastReadBookDto
     public string? LastChapter { get; init; }
     public int LastChapterIndex { get; init; }
     public string? Description { get; init; }
+    public bool IsReadyForReading { get; init; }
+}
+
+public record QuizResultDto
+{
+    public Guid Id { get; init; }
+    public string Topic { get; init; } = string.Empty;
+    public int Score { get; init; }
+    public int TotalQuestions { get; init; }
+    public double Percentage { get; init; }
+    public DateTime CompletedDate { get; init; }
 }

src/NexusReader.Application/Queries/Graph/GraphViewModels.cs

@@ -1,9 +1,27 @@
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
 namespace NexusReader.Application.Queries.Graph;
 
-public record GraphNodeDto(string Id, string Label, string Group, string? Type = null);
-public record GraphLinkDto(string Source, string Target, string RelationType, int Value = 1);
+public record GraphNodeDto(
+    [property: JsonPropertyName("id")] string Id,
+    [property: JsonPropertyName("label")] string Label,
+    [property: JsonPropertyName("group")] string Group,
+    [property: JsonPropertyName("description")] string? Description = null,
+    [property: JsonPropertyName("type")] string? Type = null,
+    [property: JsonPropertyName("summary")] string? Summary = null,
+    [property: JsonPropertyName("key_terms")] List<string>? KeyTerms = null
+);
+
+public record GraphLinkDto(
+    [property: JsonPropertyName("source")] string Source,
+    [property: JsonPropertyName("target")] string Target,
+    [property: JsonPropertyName("type")] string RelationType,
+    [property: JsonPropertyName("value")] int Value = 1
+);
+
 public record GraphDataDto
 {
-    public List<GraphNodeDto> Nodes { get; init; } = new();
-    public List<GraphLinkDto> Links { get; init; } = new();
+    [JsonPropertyName("nodes")] public List<GraphNodeDto> Nodes { get; init; } = new();
+    [JsonPropertyName("links")] public List<GraphLinkDto> Links { get; init; } = new();
 }

src/NexusReader.Application/Queries/Library/GetMyEbooksQuery.cs

@@ -37,7 +37,8 @@ public class GetMyEbooksQueryHandler : IRequestHandler<GetMyEbooksQuery, Result<
                 Progress = e.Progress,
                 LastChapter = e.LastChapter ?? "Rozpoczynanie...",
                 LastChapterIndex = e.LastChapterIndex,
-                Description = e.Description
+                Description = e.Description,
+                IsReadyForReading = e.IsReadyForReading
             })
             .ToListAsync(cancellationToken);
 

src/NexusReader.Application/Queries/User/GetUserProfileQueryHandler.cs

@@ -23,6 +23,7 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
             .Select(u => new UserProfileDto
             {
                 Email = u.Email ?? string.Empty,
+                UserId = u.Id,
                 AITokensUsed = u.AITokensUsed,
                 TenantId = u.TenantId != null && u.TenantId.Length == 36 ? new Guid(u.TenantId) : Guid.Empty,
                 Plan = u.SubscriptionPlan != null ? new SubscriptionPlanDto
@@ -35,6 +36,9 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
                 AverageQuizScore = u.QuizResults.Any(q => q.TotalQuestions > 0) 
                     ? (int)u.QuizResults.Where(q => q.TotalQuestions > 0).Average(q => (double)q.Score / q.TotalQuestions * 100) 
                     : 0,
+                DisplayName = u.DisplayName,
+                BooksReadCount = u.Ebooks.Count(),
+                ConceptsMappedCount = dbContext.KnowledgeUnits.Count(k => k.TenantId == u.TenantId || k.TenantId == "global" || string.IsNullOrEmpty(k.TenantId)),
                 LastReadBook = u.Ebooks.OrderByDescending(e => e.LastReadDate).Select(e => new LastReadBookDto
                 {
                     Id = e.Id,
@@ -48,8 +52,29 @@ public class GetUserProfileQueryHandler : IRequestHandler<GetUserProfileQuery, R
                     Progress = e.Progress,
                     LastChapter = e.LastChapter ?? "Rozpoczynanie...",
                     LastChapterIndex = e.LastChapterIndex,
-                    Description = e.Description
+                    Description = e.Description,
+                    IsReadyForReading = e.IsReadyForReading
                 }).FirstOrDefault(),
+                RecentQuizzes = u.QuizResults.OrderByDescending(q => q.CompletedDate).Take(5).Select(q => new QuizResultDto
+                {
+                    Id = q.Id,
+                    Topic = q.Topic,
+                    Score = q.Score,
+                    TotalQuestions = q.TotalQuestions,
+                    Percentage = q.Percentage,
+                    CompletedDate = q.CompletedDate
+                }).ToList(),
+                MappedConcepts = dbContext.KnowledgeUnits
+                    .Where(k => k.TenantId == u.TenantId || k.TenantId == "global" || string.IsNullOrEmpty(k.TenantId))
+                    .OrderByDescending(k => k.CreatedAt)
+                    .Take(6)
+                    .Select(k => new MappedConceptDto
+                    {
+                        Id = k.Id,
+                        Type = k.Type.ToString(),
+                        Content = k.Content
+                    })
+                    .ToList(),
                 Roles = dbContext.UserRoles
                     .Where(ur => ur.UserId == u.Id)
                     .Join(dbContext.Roles, ur => ur.RoleId, r => r.Id, (ur, r) => r.Name!)

src/NexusReader.Infrastructure/DependencyInjection.cs

@@ -112,6 +112,7 @@ public static class DependencyInjection
         services.AddScoped<IKnowledgeService, KnowledgeService>();
         services.AddTransient<IEpubReader, EpubReaderService>();
         services.AddTransient<IEpubMetadataExtractor, EpubMetadataExtractor>();
+        services.AddTransient<IEpubExtractor, EpubExtractor>();
 
         // Fix #4: Scoped instead of Singleton — BookStorageService uses path resolution
         // that is environment-specific and incompatible with Singleton lifetime in MAUI.

src/NexusReader.Infrastructure/Services/EpubExtractor.cs

@@ -0,0 +1,85 @@
+using System.Text.RegularExpressions;
+using FluentResults;
+using Microsoft.Extensions.Logging;
+using NexusReader.Application.Abstractions.Services;
+using VersOne.Epub;
+
+namespace NexusReader.Infrastructure.Services;
+
+public class EpubExtractor : IEpubExtractor
+{
+    private readonly ILogger<EpubExtractor> _logger;
+
+    public EpubExtractor(ILogger<EpubExtractor> logger)
+    {
+        _logger = logger;
+    }
+
+    public async Task<Result<List<string>>> ExtractChaptersTextAsync(string relativePath, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var fullPath = ResolvePath(relativePath);
+            if (string.IsNullOrEmpty(fullPath) || !File.Exists(fullPath))
+            {
+                _logger.LogError("[EpubExtractor] EPUB file not found at path: {FilePath}", relativePath);
+                return Result.Fail<List<string>>($"Plik EPUB nie został znaleziony na dysku: {relativePath}");
+            }
+
+            using var bookRef = await EpubReader.OpenBookAsync(fullPath);
+            var readingOrder = bookRef.GetReadingOrder();
+
+            if (readingOrder == null || !readingOrder.Any())
+            {
+                return Result.Fail<List<string>>("EPUB nie zawiera czytelnych rozdziałów.");
+            }
+
+            var chapters = new List<string>();
+            foreach (var chapterRef in readingOrder)
+            {
+                if (cancellationToken.IsCancellationRequested)
+                {
+                    break;
+                }
+
+                var rawContent = await chapterRef.ReadContentAsTextAsync();
+                var cleanText = StripHtml(rawContent);
+                chapters.Add(cleanText);
+            }
+
+            return Result.Ok(chapters);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "[EpubExtractor] Error extracting chapters from EPUB: {FilePath}", relativePath);
+            return Result.Fail<List<string>>(new Error("Failed to parse and extract text from EPUB").CausedBy(ex));
+        }
+    }
+
+    private static string? ResolvePath(string relativePath)
+    {
+        var normalized = relativePath.Replace('/', Path.DirectorySeparatorChar);
+        var currentDir = new DirectoryInfo(AppDomain.CurrentDomain.BaseDirectory);
+        while (currentDir != null)
+        {
+            var candidate = Path.Combine(currentDir.FullName, "wwwroot", normalized);
+            if (File.Exists(candidate)) return candidate;
+
+            var devCandidate = Path.Combine(currentDir.FullName, "src", "NexusReader.Web", "wwwroot", normalized);
+            if (File.Exists(devCandidate)) return devCandidate;
+
+            currentDir = currentDir.Parent;
+        }
+        return null;
+    }
+
+    private static string StripHtml(string html)
+    {
+        if (string.IsNullOrEmpty(html)) return string.Empty;
+        var clean = Regex.Replace(html, @"<(style|script)\b[^>]*>.*?</\1>", "", RegexOptions.IgnoreCase | RegexOptions.Singleline);
+        clean = Regex.Replace(clean, @"<[^>]*>", " ");
+        clean = System.Net.WebUtility.HtmlDecode(clean);
+        clean = Regex.Replace(clean, @"\s+", " ").Trim();
+        return clean;
+    }
+}

src/NexusReader.Infrastructure/Services/KnowledgeService.cs

@@ -33,7 +33,7 @@ public class KnowledgeService : IKnowledgeService
     private readonly ILogger<KnowledgeService> _logger;
     private readonly QdrantClient _qdrantClient;
     private readonly IDriver _neo4jDriver;
-    private const string PromptVersion = "1.3";
+    private const string PromptVersion = "1.7";
     private static readonly ConcurrentDictionary<string, Lazy<Task<Result<KnowledgePacket>>>> _activeRequests = new();
 
     public KnowledgeService(
@@ -85,11 +85,12 @@ public class KnowledgeService : IKnowledgeService
 
         using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
         var normalizedText = text.Trim();
-        var hash = ContentHasher.ComputeHash(normalizedText);
+        var hashInput = $"{normalizedText}:{traceType}:{PromptVersion}";
+        var hash = ContentHasher.ComputeHash(hashInput);
 
         // 1. Check Cache
         var cached = await dbContext.SemanticKnowledgeCache
-            .FirstOrDefaultAsync(c => c.ContentHash == hash && c.TenantId == tenantId, cancellationToken);
+            .FirstOrDefaultAsync(c => c.ContentHash == hash, cancellationToken);
         
         if (cached != null && cached.PromptVersion == PromptVersion)
         {
@@ -97,7 +98,12 @@ public class KnowledgeService : IKnowledgeService
             try
             {
                 var packet = JsonSerializer.Deserialize<KnowledgePacket>(cached.JsonData, JsonOptions);
-                if (packet != null) return Result.Ok(packet);
+                if (packet != null)
+                {
+                    await ProcessKnowledgeUnitsAsync(packet, tenantId, ebookId, dbContext, cancellationToken);
+                    await dbContext.SaveChangesAsync(cancellationToken);
+                    return Result.Ok(packet);
+                }
             }
             catch (JsonException ex)
             {
@@ -106,7 +112,7 @@ public class KnowledgeService : IKnowledgeService
         }
 
         // Deduplicate concurrent active requests for the exact same hash
-        var requestKey = $"{tenantId}:{hash}:{traceType}";
+        var requestKey = $"{hash}:{traceType}";
         
         var lazyTask = _activeRequests.GetOrAdd(requestKey, k => 
             new Lazy<Task<Result<KnowledgePacket>>>(
@@ -178,7 +184,7 @@ public class KnowledgeService : IKnowledgeService
                 
                 // 4. Save to Cache
                 var cached = await dbContext.SemanticKnowledgeCache
-                    .FirstOrDefaultAsync(c => c.ContentHash == hash && c.TenantId == tenantId);
+                    .FirstOrDefaultAsync(c => c.ContentHash == hash);
 
                 var cacheEntry = new SemanticKnowledgeCache
                 {
@@ -202,7 +208,14 @@ public class KnowledgeService : IKnowledgeService
                 // 5. Process structured KnowledgeUnits (Graph Expansion)
                 await ProcessKnowledgeUnitsAsync(knowledgePacket, tenantId, ebookId, dbContext, default);
 
-                await dbContext.SaveChangesAsync();
+                try
+                {
+                    await dbContext.SaveChangesAsync();
+                }
+                catch (DbUpdateException ex) when (ex.InnerException is Npgsql.PostgresException pgEx && pgEx.SqlState == "23505")
+                {
+                    _logger.LogWarning("[KnowledgeService] Concurrency collision on SemanticKnowledgeCache for {Hash}; another process saved it first. Swallowing.", hash);
+                }
                 return Result.Ok(knowledgePacket);
             }
             catch (JsonException ex)
@@ -225,6 +238,30 @@ public class KnowledgeService : IKnowledgeService
 
     private async Task ProcessKnowledgeUnitsAsync(KnowledgePacket packet, string tenantId, Guid? ebookId, AppDbContext dbContext, CancellationToken cancellationToken)
     {
+        if (packet.Graph != null && (packet.Units == null || !packet.Units.Any()))
+        {
+            var graphUnits = packet.Graph.Nodes.Select(node => new KnowledgeUnitDto(
+                node.Id,
+                node.Type ?? "concept",
+                node.Description ?? node.Label,
+                new Dictionary<string, object>
+                {
+                    ["label"] = node.Label,
+                    ["group"] = node.Group,
+                    ["summary"] = node.Summary ?? "",
+                    ["key_terms"] = node.KeyTerms ?? new List<string>()
+                }
+            )).ToList();
+
+            var graphLinks = packet.Graph.Links.Select(link => new KnowledgeLinkDto(
+                link.Source,
+                link.Target,
+                link.RelationType
+            )).ToList();
+
+            packet = packet with { Units = graphUnits, Links = graphLinks };
+        }
+
         var unitIds = packet.Units.Select(u => u.Id).ToList();
         var linkSourceIds = packet.Links.Select(l => l.Source).ToList();
         var linkTargetIds = packet.Links.Select(l => l.Target).ToList();
@@ -340,6 +377,79 @@ public class KnowledgeService : IKnowledgeService
                 _logger.LogError(ex, "[KnowledgeService] Failed to generate and upsert embeddings for knowledge units to Qdrant.");
             }
         }
+
+        // 6. Synchronize to Neo4j graph database
+        await SyncToNeo4jAsync(packet, cancellationToken);
+    }
+
+    private async Task SyncToNeo4jAsync(KnowledgePacket packet, CancellationToken cancellationToken)
+    {
+        if (packet.Units == null || !packet.Units.Any()) return;
+
+        try
+        {
+            await using var session = _neo4jDriver.AsyncSession();
+
+            // 1. Merge nodes in a transaction
+            await session.ExecuteWriteAsync(async tx =>
+            {
+                foreach (var unit in packet.Units)
+                {
+                    var cypher = @"
+                        MERGE (u:KnowledgeUnit {id: $id})
+                        ON CREATE SET u.content = $content, u.type = $type
+                        ON MATCH SET u.content = $content, u.type = $type";
+                    
+                    var guidStr = GetDeterministicGuid(unit.Id).ToString();
+                    await tx.RunAsync(cypher, new 
+                    { 
+                        id = guidStr, 
+                        content = unit.Content ?? string.Empty, 
+                        type = unit.Type ?? "concept" 
+                    });
+                }
+            });
+
+            // 2. Merge links in a transaction
+            if (packet.Links != null && packet.Links.Any())
+            {
+                await session.ExecuteWriteAsync(async tx =>
+                {
+                    foreach (var link in packet.Links)
+                    {
+                        if (string.IsNullOrWhiteSpace(link.Source) || string.IsNullOrWhiteSpace(link.Target))
+                            continue;
+
+                        var relationType = string.IsNullOrWhiteSpace(link.Relation) ? "RELATED_TO" : link.Relation.Trim().ToUpperInvariant();
+                        relationType = System.Text.RegularExpressions.Regex.Replace(relationType, @"[^A-Z0-9_]", "_");
+                        if (string.IsNullOrEmpty(relationType) || relationType == "_")
+                        {
+                            relationType = "RELATED_TO";
+                        }
+
+                        var cypher = $@"
+                            MATCH (source:KnowledgeUnit {{id: $sourceId}})
+                            MATCH (target:KnowledgeUnit {{id: $targetId}})
+                            MERGE (source)-[r:{relationType}]->(target)";
+
+                        var sourceGuidStr = GetDeterministicGuid(link.Source).ToString();
+                        var targetGuidStr = GetDeterministicGuid(link.Target).ToString();
+
+                        await tx.RunAsync(cypher, new 
+                        { 
+                            sourceId = sourceGuidStr, 
+                            targetId = targetGuidStr 
+                        });
+                    }
+                });
+            }
+
+            _logger.LogInformation("[KnowledgeService] Successfully synchronized {NodeCount} nodes and {LinkCount} links to Neo4j.", packet.Units.Count, packet.Links?.Count ?? 0);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "[KnowledgeService] Failed to synchronize knowledge graph to Neo4j.");
+        }
     }
 
     private async Task EnsureCollectionExistsAsync(string collectionName, CancellationToken cancellationToken = default)
@@ -380,6 +490,14 @@ public class KnowledgeService : IKnowledgeService
         return new Guid(hash);
     }
 
+    private static string GetPointIdString(PointId pointId)
+    {
+        if (pointId == null) return string.Empty;
+        return pointId.PointIdOptionsCase == PointId.PointIdOptionsOneofCase.Uuid
+            ? pointId.Uuid
+            : pointId.Num.ToString();
+    }
+
     public async Task<Result<GroundednessResult>> VerifyGroundednessAsync(string answer, string context, string tenantId, CancellationToken cancellationToken = default)
     {
         var systemPrompt = @"
@@ -462,10 +580,28 @@ public class KnowledgeService : IKnowledgeService
                 searchResult = new List<Qdrant.Client.Grpc.ScoredPoint>();
             }
 
-            var contexts = searchResult.Select(point => new RelevantContext 
+            var contexts = searchResult.Select(point => 
             { 
-                Text = point.Payload.TryGetValue("content", out var cv) ? cv.StringValue : string.Empty, 
-                Confidence = point.Score 
+                var content = point.Payload.TryGetValue("content", out var cv) ? cv.StringValue : string.Empty;
+                var summary = string.Empty;
+                if (point.Payload.TryGetValue("metadataJson", out var metaVal) && !string.IsNullOrEmpty(metaVal.StringValue))
+                {
+                    try
+                    {
+                        var meta = JsonSerializer.Deserialize<Dictionary<string, object>>(metaVal.StringValue);
+                        if (meta != null && meta.TryGetValue("summary", out var sumObj))
+                        {
+                            summary = sumObj?.ToString();
+                        }
+                    }
+                    catch {}
+                }
+                var text = string.IsNullOrEmpty(summary) ? content : $"{content}: {summary}";
+                return new RelevantContext 
+                { 
+                    Text = text, 
+                    Confidence = point.Score 
+                };
             }).ToList();
 
             return Result.Ok(contexts);
@@ -533,7 +669,7 @@ public class KnowledgeService : IKnowledgeService
             }
 
             // 3. Graph Expansion via Neo4j
-            var candidateIds = searchResult.Select(r => r.Id.ToString()).ToList();
+            var candidateIds = searchResult.Select(r => GetPointIdString(r.Id)).ToList();
             var definitions = new Dictionary<string, List<string>>();
 
             if (candidateIds.Any())
@@ -542,7 +678,7 @@ public class KnowledgeService : IKnowledgeService
                 {
                     await using var session = _neo4jDriver.AsyncSession();
                     var cypher = @"
-                        MATCH (source:KnowledgeUnit)-[r:DEFINES]->(target:KnowledgeUnit)
+                        MATCH (source:KnowledgeUnit)-[r]->(target:KnowledgeUnit)
                         WHERE source.id IN $candidateIds
                         RETURN source.id AS sourceId, target.content AS targetContent";
                     
@@ -616,7 +752,7 @@ public class KnowledgeService : IKnowledgeService
 
                 var dto = new SemanticSearchResultDto
                 {
-                    ContentHash = point.Id.ToString(),
+                    ContentHash = GetPointIdString(point.Id),
                     Snippet = content,
                     UnitType = type,
                     RelevanceScore = point.Score,
@@ -624,7 +760,7 @@ public class KnowledgeService : IKnowledgeService
                     Metadata = metadata
                 };
 
-                var pointIdStr = point.Id.ToString();
+                var pointIdStr = GetPointIdString(point.Id);
                 if (definitions.TryGetValue(pointIdStr, out var pointDefs) && pointDefs.Any())
                 {
                     dto.Snippet = $"[Context: {string.Join("; ", pointDefs)}]\n{dto.Snippet}";
@@ -723,11 +859,26 @@ public class KnowledgeService : IKnowledgeService
             }
 
             // 3. Graph Expansion via Neo4j
-            var candidateIds = searchResult.Select(r => r.Id.ToString()).ToList();
+            var candidateIds = searchResult.Select(r => GetPointIdString(r.Id)).ToList();
             var relatedContexts = new List<string>();
             
             // Keep map of point ID -> payload data for fast mapping later
-            var pointMap = searchResult.ToDictionary(r => r.Id.ToString(), r => r);
+            var pointMap = searchResult.ToDictionary(r => GetPointIdString(r.Id), r => r);
+
+            // Fetch knowledge units from PostgreSQL to map Guids back to rich metadata summaries
+            var guidMap = new Dictionary<string, KnowledgeUnit>();
+            try
+            {
+                using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+                var units = await dbContext.KnowledgeUnits
+                    .Where(u => u.TenantId == tenantId && (ebookId == null || u.EbookId == ebookId))
+                    .ToListAsync(cancellationToken);
+                guidMap = units.ToDictionary(u => GetDeterministicGuid(u.Id).ToString(), u => u);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "[KnowledgeService] Failed to load KnowledgeUnits from PostgreSQL for Guid mapping.");
+            }
 
             if (candidateIds.Any())
             {
@@ -737,7 +888,7 @@ public class KnowledgeService : IKnowledgeService
                     var cypher = @"
                         MATCH (source:KnowledgeUnit)
                         WHERE source.id IN $candidateIds
-                        OPTIONAL MATCH (source)-[r:DEFINES|RELATED_TO]->(target:KnowledgeUnit)
+                        OPTIONAL MATCH (source)-[r]->(target:KnowledgeUnit)
                         RETURN source.id AS sourceId, source.content AS sourceContent,
                                collect({ targetId: target.id, targetContent: target.content, relation: type(r) }) AS relations";
                     
@@ -750,23 +901,64 @@ public class KnowledgeService : IKnowledgeService
                     foreach (var record in neoResult)
                     {
                         var sourceId = record["sourceId"].As<string>();
-                        var sourceContent = record["sourceContent"].As<string>();
                         
-                        relatedContexts.Add($"[Source ID: {sourceId}] {sourceContent}");
+                        var sourceText = string.Empty;
+                        if (guidMap.TryGetValue(sourceId, out var sourceUnit))
+                        {
+                            var summary = string.Empty;
+                            if (!string.IsNullOrEmpty(sourceUnit.MetadataJson))
+                            {
+                                try
+                                {
+                                    var meta = JsonSerializer.Deserialize<Dictionary<string, object>>(sourceUnit.MetadataJson);
+                                    if (meta != null && meta.TryGetValue("summary", out var sumObj))
+                                    {
+                                        summary = sumObj?.ToString();
+                                    }
+                                }
+                                catch { }
+                            }
+                            sourceText = string.IsNullOrEmpty(summary) ? sourceUnit.Content : $"{sourceUnit.Content}: {summary}";
+                        }
+                        else
+                        {
+                            sourceText = record["sourceContent"].As<string>();
+                        }
+                        
+                        relatedContexts.Add($"[Source ID: {sourceId}] {sourceText}");
                         
                         var relations = record["relations"].As<List<object>>();
                         if (relations != null)
                         {
                             foreach (var relObj in relations)
                             {
-                                if (relObj is Dictionary<string, object> relDict &&
-                                    relDict.TryGetValue("targetId", out var targetIdVal) && targetIdVal is string targetId &&
-                                    relDict.TryGetValue("targetContent", out var targetContentVal) && targetContentVal is string targetContent &&
-                                    relDict.TryGetValue("relation", out var relationVal) && relationVal is string relation)
+                                if (relObj is System.Collections.IDictionary relDict)
                                 {
-                                    if (!string.IsNullOrEmpty(targetContent))
+                                    var targetId = relDict["targetId"]?.ToString();
+                                    var targetContent = relDict["targetContent"]?.ToString();
+                                    var relation = relDict["relation"]?.ToString();
+
+                                    if (!string.IsNullOrEmpty(targetContent) && !string.IsNullOrEmpty(relation))
                                     {
-                                        relatedContexts.Add($"[Related Context ({relation}) to {sourceId}] {targetContent}");
+                                        var targetText = targetContent;
+                                        if (!string.IsNullOrEmpty(targetId) && guidMap.TryGetValue(targetId, out var targetUnit))
+                                        {
+                                            var summary = string.Empty;
+                                            if (!string.IsNullOrEmpty(targetUnit.MetadataJson))
+                                            {
+                                                try
+                                                {
+                                                    var meta = JsonSerializer.Deserialize<Dictionary<string, object>>(targetUnit.MetadataJson);
+                                                    if (meta != null && meta.TryGetValue("summary", out var sumObj))
+                                                    {
+                                                        summary = sumObj?.ToString();
+                                                    }
+                                                }
+                                                catch { }
+                                            }
+                                            targetText = string.IsNullOrEmpty(summary) ? targetUnit.Content : $"{targetUnit.Content}: {summary}";
+                                        }
+                                        relatedContexts.Add($"[Related Context ({relation}) to {sourceId}] {targetText}");
                                     }
                                 }
                             }
@@ -778,9 +970,32 @@ public class KnowledgeService : IKnowledgeService
                     _logger.LogWarning(ex, "[KnowledgeService] Neo4j graph expansion failed. Falling back to direct Qdrant points.");
                     foreach (var point in searchResult)
                     {
-                        var sourceId = point.Id.ToString();
-                        var content = point.Payload.TryGetValue("content", out var cv) ? cv.StringValue : string.Empty;
-                        relatedContexts.Add($"[Source ID: {sourceId}] {content}");
+                        var sourceId = GetPointIdString(point.Id);
+                        
+                        var sourceText = string.Empty;
+                        if (guidMap.TryGetValue(sourceId, out var sourceUnit))
+                        {
+                            var summary = string.Empty;
+                            if (!string.IsNullOrEmpty(sourceUnit.MetadataJson))
+                            {
+                                try
+                                {
+                                    var meta = JsonSerializer.Deserialize<Dictionary<string, object>>(sourceUnit.MetadataJson);
+                                    if (meta != null && meta.TryGetValue("summary", out var sumObj))
+                                    {
+                                        summary = sumObj?.ToString();
+                                    }
+                                }
+                                catch { }
+                            }
+                            sourceText = string.IsNullOrEmpty(summary) ? sourceUnit.Content : $"{sourceUnit.Content}: {summary}";
+                        }
+                        else
+                        {
+                            sourceText = point.Payload.TryGetValue("content", out var cv) ? cv.StringValue : string.Empty;
+                        }
+
+                        relatedContexts.Add($"[Source ID: {sourceId}] {sourceText}");
                     }
                 }
             }
@@ -804,33 +1019,14 @@ public class KnowledgeService : IKnowledgeService
             // 5. Build prompt and invoke Gemini with structured JSON formatting
             var contextBlocksText = string.Join("\n\n", relatedContexts);
 
-            var systemPrompt = @"
-You are an advanced, extremely precise Fact-Checking AI assistant. Your task is to answer the user's question using ONLY the provided context blocks.
-
-Strict Grounding Rules:
-1. Rely EXCLUSIVELY on the provided context. Do NOT use any pre-existing external knowledge, facts, or assumptions.
-2. If the context does not contain the answer, you must state exactly: 'I cannot answer this based on the provided book context.'
-3. For every statement or claim you make in your answer, you must cite the specific source IDs (e.g., source chunk ID or hash) from the context.
-4. You must format your response ONLY as a JSON object matching the following structure:
-{
-  ""answer"": ""The answer text goes here, referencing [Source ID] as citations."",
-  ""citations"": [
-    {
-      ""citationId"": ""The exact source ID cited (e.g., chunk hash/ID)"",
-      ""snippet"": ""The precise sentence or phrase from the context that supports this statement."",
-      ""sourceBook"": ""The book title or 'Unknown'""
-    }
-  ]
-}
-";
+            var systemPrompt = PromptRegistry.GroundedRAGSystemPrompt;
 
             var userPrompt = $"Context:\n{contextBlocksText}\n\nQuestion: {question}";
 
             var options = new ChatOptions
             {
                 Temperature = 0.0f,
-                MaxOutputTokens = 1500,
-                ResponseFormat = ChatResponseFormat.Json
+                MaxOutputTokens = 1500
             };
 
             var chatResponse = await _retryPipeline.ExecuteAsync(async ct => 
@@ -842,6 +1038,20 @@ Strict Grounding Rules:
 
             var rawJson = chatResponse.Text?.Trim() ?? string.Empty;
             rawJson = rawJson.Replace("```json", "").Replace("```", "").Trim();
+
+            // Handle direct text fallback when model bypasses JSON format
+            if (!rawJson.StartsWith("{") && 
+                (rawJson.Contains("cannot answer", StringComparison.OrdinalIgnoreCase) || 
+                 rawJson.Contains("context does not contain", StringComparison.OrdinalIgnoreCase) || 
+                 rawJson.Contains("provided book context", StringComparison.OrdinalIgnoreCase)))
+            {
+                return Result.Ok(new GroundedResponseDto
+                {
+                    Answer = "I cannot answer this based on the provided book context.",
+                    Citations = new List<CitationDto>()
+                });
+            }
+
             rawJson = JsonRepairHelper.Repair(rawJson);
 
             try
@@ -852,15 +1062,52 @@ Strict Grounding Rules:
                     return Result.Fail("Failed to deserialize grounded RAG response.");
                 }
 
-                // Hydrate book titles for citations if unknown
+                // Hydrate book titles, author, and page number for citations if unknown
                 foreach (var citation in groundedResult.Citations)
                 {
                     if (pointMap.TryGetValue(citation.CitationId, out var point) && 
                         point.Payload.TryGetValue("ebookId", out var ev) && 
-                        Guid.TryParse(ev.StringValue, out var ebId) && 
-                        ebookTitles.TryGetValue(ebId, out var title))
+                        Guid.TryParse(ev.StringValue, out var ebId))
                     {
-                        citation.SourceBook = title;
+                        if (ebookTitles.TryGetValue(ebId, out var title))
+                        {
+                            citation.SourceBook = title;
+                        }
+                    }
+
+                    // Look up from guidMap to get exact page number and author
+                    if (guidMap.TryGetValue(citation.CitationId, out var unit))
+                    {
+                        if (unit.Ebook?.Author != null)
+                        {
+                            citation.Author = unit.Ebook.Author.Name;
+                        }
+                        else if (unit.EbookId.HasValue)
+                        {
+                            try
+                            {
+                                using var dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+                                var eb = await dbContext.Ebooks.Include(e => e.Author).FirstOrDefaultAsync(e => e.Id == unit.EbookId.Value, cancellationToken);
+                                if (eb?.Author != null)
+                                {
+                                    citation.Author = eb.Author.Name;
+                                }
+                            }
+                            catch { }
+                        }
+
+                        if (!string.IsNullOrEmpty(unit.MetadataJson))
+                        {
+                            try
+                            {
+                                var meta = JsonSerializer.Deserialize<Dictionary<string, object>>(unit.MetadataJson);
+                                if (meta != null && meta.TryGetValue("page", out var pageObj) && int.TryParse(pageObj?.ToString(), out var pageVal))
+                                {
+                                    citation.PageNumber = pageVal;
+                                }
+                            }
+                            catch { }
+                        }
                     }
                 }
 
@@ -896,6 +1143,20 @@ Strict Grounding Rules:
                 _logger.LogWarning(ex, "[KnowledgeService] Failed to drop Qdrant collection 'knowledge_units' during cache clear.");
             }
 
+            try
+            {
+                await using var session = _neo4jDriver.AsyncSession();
+                await session.ExecuteWriteAsync(async tx =>
+                {
+                    await tx.RunAsync("MATCH (n:KnowledgeUnit) DETACH DELETE n");
+                });
+                _logger.LogInformation("[KnowledgeService] Successfully wiped Neo4j 'KnowledgeUnit' nodes.");
+            }
+            catch (Exception ex)
+            {
+                _logger.LogWarning(ex, "[KnowledgeService] Failed to wipe Neo4j graph during cache clear.");
+            }
+
             return Result.Ok();
         }
         catch (Exception ex)

src/NexusReader.Infrastructure/Services/PromptRegistry.cs

@@ -4,9 +4,10 @@ public static class PromptRegistry
 {
     public const string KnowledgeExtractionSystemPrompt = 
         "You are an expert educator. Analyze the provided text to extract key concepts, generate relevant quizzes, and construct a knowledge graph. " +
-        "CRITICAL: Restrict 'concept.label' to a maximum of 3 words (e.g., 'Dependency Injection' instead of full sentences). " +
+        "**LANGUAGE CRITICAL**: Detect the language of the provided text. You MUST generate all human-readable fields ('title', 'description', 'question', 'options', 'label') in the EXACT SAME LANGUAGE as the source text. Do NOT translate them to English unless the source text is in English. " +
+        "CRITICAL: Restrict 'concept.label' to a maximum of 3 words (e.g., 'Dependency Injection' or its exact foreign equivalent, never full sentences). " +
         "CRITICAL: Extract a MAXIMUM of 15 key concepts/plot points from the text. " +
-        "CRITICAL: Code blocks (e.g., markdown code snippets) must be excluded from the relationship graph, or summarized as a single node (e.g., 'Code Example'). Do NOT create nodes for variables, functions, namespaces, or individual lines of code. " +
+        "CRITICAL: Code blocks (e.g., markdown code snippets) must be excluded from the relationship graph, or summarized as a single node with the label 'Code Example' translated to the detected language. Do NOT create nodes for variables, functions, namespaces, or individual lines of code. " +
         "CRITICAL: Return ONLY a minified JSON object. Do NOT include markdown formatting like ```json or ```. Do NOT include explanations. " +
         "Schema: { " +
         "\"concepts\": [ { \"title\": \"string\", \"description\": \"string\" } ], " +
@@ -15,28 +16,66 @@ public static class PromptRegistry
         "}.";
 
     public const string GraphExtractionPrompt = 
-        "You are an expert at information architecture. Extract key concepts and paragraph mappings from the text to build a unified knowledge graph. " +
-        "The input text consists of several paragraphs, each starting with its unique block ID in the format '[ID: seg-X]'. " +
-        "Extract two types of nodes: " +
-        "1. Concept Nodes (group: 'concept'): Extract the main technical concepts discussed (e.g., ID: 'dependency-injection', label: 'Dependency Injection'). Max 10 concepts. Labels must be at most 3 words. " +
-        "2. Block Nodes (group: 'current'): For each paragraph in the input, create a node representing that paragraph where 'id' is the exact block ID (e.g., 'seg-1'), and 'label' is a brief summary of that paragraph's content (max 3 words). " +
-        "CRITICAL: If a paragraph is a code block, represent it as a single block node with label 'Code Example' (group: 'current'). Do NOT extract low-level code elements (like variables, classes, methods, or namespaces) as separate concept nodes. " +
-        "CRITICAL: Connect related concept nodes together, and connect each concept node to the block nodes ('seg-X') where it is discussed. " +
-        "Limit connections to a MAXIMUM of 15 most relevant links. " +
-        "Return ONLY minified JSON. Schema: { \"graph\": { \"nodes\": [ { \"id\": \"string\", \"label\": \"string\", \"group\": \"concept|current\" } ], \"links\": [ { \"source\": \"string\", \"target\": \"string\", \"value\": 1 } ] } }";
-
+        "You are a strict Minimalist Information Architect. Your sole job is to build a high-level, sparse linear backbone for a textbook chapter. " +
+        "**LANGUAGE CRITICAL**: Detect the language of the provided text. The 'label', 'summary', and 'key_terms' fields MUST be in the EXACT SAME LANGUAGE as the source text. " +
+        "The input text consists of sections starting with block IDs (e.g., '[ID: seg-4]'). " +
+        "CRITICAL TOPOLOGY RULES (ZERO TOLERANCE FOR CLUTTER): " +
+        "1. HARD NODE LIMIT: You are strictly forbidden from extracting more than 4 to 5 nodes IN TOTAL for the entire text. If there are more sections, select ONLY the 4-5 absolute most critical, high-level structural pillars. " +
+        "2. NO CONCEPT CLOUDS: Do NOT create nodes for individual technologies, files, terms, or phrases (e.g., 'Kestrel', 'appsettings.json', 'DI', 'Blazor Server' must NEVER be nodes). They must ONLY exist as text strings inside the 'key_terms' array of a major node. " +
+        "3. LINEAR SPINE PATTERN: Nodes must form a clear, clean path or simple tree representing the chronological reading journey (e.g., Node 1 -> Node 2 -> Node 3). Do NOT create complex web loops or interconnect every node. Limit total links in the entire JSON to maximum 4 or 5 links. " +
+        "4. NODE DATA STRUCTURE: " +
+        "   - 'id': must be the exact block ID (e.g., 'seg-16'). " +
+        "   - 'label': clear technical title (Max 3 words, e.g., 'Blazor Hosting Models'). " +
+        "   - 'group': strictly either 'bridge' (if it compares legacy vs modern) or 'concept' (for standalone core pillars). " +
+        "   - 'summary': exact 2-sentence distillation for the Contextual Panel. " +
+        "   - 'key_terms': array of max 5 short strings representing the micro-concepts hidden inside this section. " +
+        "System keys configuration: All JSON keys ('nodes', 'links', 'id', 'label', 'group', 'summary', 'key_terms', 'source', 'target', 'type') must remain strictly in English. " +
+        "Return ONLY minified JSON. Schema: " +
+        "{ " +
+        "  \"graph\": { " +
+        "    \"nodes\": [ " +
+        "      { \"id\": \"seg-X\", \"label\": \"string\", \"group\": \"concept|bridge\", \"summary\": \"string\", \"key_terms\": [ \"string\" ] } " +
+        "    ], " +
+        "    \"links\": [ " +
+        "      { \"source\": \"seg-X\", \"target\": \"seg-Y\", \"type\": \"maps_to|contains\" } " +
+        "    ] " +
+        "  } " +
+        "}";
 
     public const string SummaryAndQuizPrompt = 
         "You are an expert educator. Provide a concise summary of the text and generate a challenging quiz (3-5 questions). " +
+        "**LANGUAGE CRITICAL**: Detect the language of the provided text. The generated 'summary', 'question', and 'options' MUST be in the EXACT SAME LANGUAGE as the source text. " +
         "Return ONLY minified JSON. Schema: { \"summary\": \"string\", \"quizzes\": [ { \"question\": \"string\", \"options\": [ \"string\" ], \"correct_index\": 0 } ] }";
 
     public const string KM_ExtractionPrompt = 
         "You are an expert at Knowledge Engineering. Segment the provided text into discrete Knowledge Units. " +
+        "**LANGUAGE CRITICAL**: Detect the language of the provided text. The 'content' field MUST be in the EXACT SAME LANGUAGE as the source text. " +
         "Identify 'units' (sections, tables, definitions, rules) and 'links' (how they relate). " +
         "CRITICAL: Units must be granular. " +
-        "CRITICAL: Code blocks must be summarized under the parent unit or represented as a single 'Code Example' unit. Do NOT segment code blocks into granular low-level code details (e.g., classes, variables, parameters). " +
+        "CRITICAL: Code blocks must be summarized under the parent unit or represented as a single 'Code Example' unit (translate the name to the detected language). Do NOT segment code blocks into granular low-level code details (e.g., classes, variables, parameters). " +
+        "CRITICAL SYSTEM VALUES: The fields 'type' (strictly: 'Section', 'Table', 'Definition', or 'Rule') and 'relation' (strictly: 'Next', 'Defines', 'Contains', or 'References') are system keys and MUST remain in English as specified. " +
         "Schema: { " +
         "\"units\": [ { \"id\": \"string\", \"type\": \"Section|Table|Definition|Rule\", \"content\": \"string\", \"metadata\": { \"page\": 0 } } ], " +
         "\"links\": [ { \"source\": \"string\", \"target\": \"string\", \"relation\": \"Next|Defines|Contains|References\" } ] " +
         "}.";
+
+    public const string GroundedRAGSystemPrompt = """
+        You are an advanced, extremely precise Fact-Checking AI assistant. Your task is to answer the user's question using ONLY the provided context blocks.
+
+        Strict Grounding Rules:
+        1. Rely EXCLUSIVELY on the provided context. Do NOT use any pre-existing external knowledge, facts, or assumptions.
+        2. If the context does not contain the answer, you must set the "answer" property in the JSON object exactly to: 'I cannot answer this based on the provided book context.' and the "citations" array must be empty.
+        3. For every statement or claim you make in your answer, you must cite the specific source IDs (e.g., source chunk ID or hash) from the context.
+        4. You must format your response ONLY as a JSON object matching the following structure:
+        {
+          "answer": "The answer text goes here, referencing [Source ID] as citations.",
+          "citations": [
+            {
+              "citationId": "The exact source ID cited (e.g., chunk hash/ID)",
+              "snippet": "The precise sentence or phrase from the context that supports this statement.",
+              "sourceBook": "The book title or 'Unknown'"
+            }
+          ]
+        }
+        """;
 }

src/NexusReader.UI.Shared/Components/Atoms/NexusCitationMarker.razor

@@ -0,0 +1,76 @@
+@using NexusReader.Application.DTOs.AI
+
+<div class="nexus-citation-container" @onmouseenter="ShowPopup" @onmouseleave="HidePopup">
+    <button type="button" class="nexus-citation-trigger" aria-label="Citation source">
+        <!-- Circular Neon SVG Radar Ping / Stylized Book Icon -->
+        <svg class="neon-radar-svg" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
+            <circle cx="12" cy="12" r="10"></circle>
+            <circle cx="12" cy="12" r="6"></circle>
+            <circle cx="12" cy="12" r="2"></circle>
+        </svg>
+        <span class="pulse-ring"></span>
+    </button>
+
+    @if (_isHovered && _citation != null)
+    {
+        <div class="nexus-citation-popup">
+            <div class="popup-header">
+                <span class="book-title"><i class="bi bi-book-half"></i> @_citation.SourceBook</span>
+                @if (!string.IsNullOrEmpty(_citation.Author))
+                {
+                    <span class="separator">•</span>
+                    <span class="book-author">@_citation.Author</span>
+                }
+                @if (_citation.PageNumber.HasValue)
+                {
+                    <span class="separator">•</span>
+                    <span class="page-number">Page @_citation.PageNumber.Value</span>
+                }
+            </div>
+            <div class="popup-body">
+                <p class="citation-quote">"@_citation.Snippet"</p>
+            </div>
+            <div class="popup-footer">
+                <span class="id-badge">ID: @SourceId.Substring(0, Math.Min(8, SourceId.Length))</span>
+            </div>
+        </div>
+    }
+</div>
+
+@code {
+    [Parameter]
+    [EditorRequired]
+    public string SourceId { get; set; } = string.Empty;
+
+    [Parameter]
+    public List<CitationDto>? Citations { get; set; }
+
+    private bool _isHovered;
+    private CitationDto? _citation;
+
+    protected override void OnParametersSet()
+    {
+        _citation = Citations?.FirstOrDefault(c => c.CitationId.Equals(SourceId, System.StringComparison.OrdinalIgnoreCase));
+        
+        // If not found in the thread citations, provide a clean fallback so the UI never displays an empty error
+        if (_citation == null)
+        {
+            _citation = new CitationDto
+            {
+                CitationId = SourceId,
+                SourceBook = "Grounded Document Chunk",
+                Snippet = "Context snippet retrieved from vector search node."
+            };
+        }
+    }
+
+    private void ShowPopup()
+    {
+        _isHovered = true;
+    }
+
+    private void HidePopup()
+    {
+        _isHovered = false;
+    }
+}

src/NexusReader.UI.Shared/Components/Atoms/NexusCitationMarker.razor.css

@@ -0,0 +1,148 @@
+.nexus-citation-container {
+    position: relative;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    vertical-align: middle;
+    margin: 0 4px;
+}
+
+.nexus-citation-trigger {
+    background: transparent;
+    border: none;
+    padding: 0;
+    margin: 0;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    color: #06b6d4; /* Glowing Cyan */
+    width: 20px;
+    height: 20px;
+    position: relative;
+    outline: none;
+    transition: all 0.3s ease;
+}
+
+.nexus-citation-trigger:hover {
+    color: #00ff99; /* Neon Green on hover */
+    transform: scale(1.2);
+}
+
+.neon-radar-svg {
+    width: 100%;
+    height: 100%;
+    filter: drop-shadow(0 0 4px currentColor);
+    animation: radar-spin 8s linear infinite;
+}
+
+.pulse-ring {
+    position: absolute;
+    width: 100%;
+    height: 100%;
+    border: 1px solid currentColor;
+    border-radius: 50%;
+    animation: radar-ping 1.5s cubic-bezier(0, 0, 0.2, 1) infinite;
+    opacity: 0;
+    pointer-events: none;
+}
+
+.nexus-citation-popup {
+    position: absolute;
+    bottom: calc(100% + 10px);
+    left: 50%;
+    transform: translateX(-50%) translateY(5px);
+    width: 320px;
+    padding: 1rem;
+    border-radius: 12px;
+    background: rgba(10, 16, 26, 0.9); /* Premium dark background */
+    border: 1px solid rgba(6, 182, 212, 0.25); /* Cyan border */
+    backdrop-filter: blur(12px);
+    -webkit-backdrop-filter: blur(12px);
+    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5), 0 0 12px rgba(6, 182, 212, 0.15);
+    z-index: 1000;
+    pointer-events: none;
+    opacity: 0;
+    animation: popup-fade-in 0.2s cubic-bezier(0.16, 1, 0.3, 1) forwards;
+    transform-origin: bottom center;
+}
+
+.popup-header {
+    display: flex;
+    align-items: center;
+    flex-wrap: wrap;
+    gap: 4px;
+    font-size: 0.75rem;
+    font-weight: 700;
+    color: #00ff99; /* Emerald/Neon Green micro-header */
+    text-transform: uppercase;
+    letter-spacing: 0.5px;
+    margin-bottom: 0.5rem;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
+    padding-bottom: 0.35rem;
+}
+
+.separator {
+    color: rgba(255, 255, 255, 0.3);
+}
+
+.book-title {
+    display: flex;
+    align-items: center;
+    gap: 4px;
+}
+
+.book-author, .page-number {
+    color: rgba(255, 255, 255, 0.6);
+}
+
+.popup-body {
+    margin-bottom: 0.5rem;
+}
+
+.citation-quote {
+    font-size: 0.85rem;
+    line-height: 1.4;
+    color: rgba(255, 255, 255, 0.95);
+    font-style: italic;
+    margin: 0;
+}
+
+.popup-footer {
+    display: flex;
+    justify-content: flex-end;
+}
+
+.id-badge {
+    font-size: 0.65rem;
+    color: rgba(255, 255, 255, 0.3);
+    font-family: monospace;
+}
+
+/* Animations */
+@keyframes radar-spin {
+    0% { transform: rotate(0deg); }
+    100% { transform: rotate(360deg); }
+}
+
+@keyframes radar-ping {
+    0% {
+        transform: scale(1);
+        opacity: 0.8;
+    }
+    100% {
+        transform: scale(2.2);
+        opacity: 0;
+    }
+}
+
+@keyframes popup-fade-in {
+    0% {
+        opacity: 0;
+        transform: translateX(-50%) translateY(8px) scale(0.95);
+    }
+    100% {
+        opacity: 1;
+        transform: translateX(-50%) translateY(0) scale(1);
+    }
+}

src/NexusReader.UI.Shared/Components/Molecules/KnowledgeCheck.razor

@@ -2,9 +2,14 @@
 @using NexusReader.Application.Queries.Quiz
 @using NexusReader.Application.Commands.Quiz
 @using NexusReader.Application.Abstractions.Services
+@using NexusReader.UI.Shared.Components.Atoms
+@using NexusReader.UI.Shared.Services
 @inject IMediator Mediator
 @inject IPlatformService PlatformService
 @inject IQuizStateService QuizService
+@inject IIdentityService IdentityService
+@inject IKnowledgeGraphService GraphService
+@inject KnowledgeCoordinator Coordinator
 
 <div class="knowledge-check">
     <div class="quiz-header">
@@ -12,10 +17,33 @@
         <button class="expand-btn">⌵</button>
     </div>
 
-    @if (QuizService.IsHydrating)
+    @if (QuizService.IsHydrating || _isGenerating)
     {
         <div class="loading-state shimmer">Skanowanie wiedzy przez AI...</div>
     }
+    else if (_isSubmitted)
+    {
+        <div class="submitted-container">
+            <div class="success-icon-wrapper">
+                <NexusIcon Name="check" Size="48" Class="success-glow" />
+            </div>
+            <h3 class="submitted-title">Gratulacje!</h3>
+            <p class="submitted-text">Sprawdzian zakończony pomyślnie. Twój wynik został zapisany w bazie danych.</p>
+            
+            <div class="score-card">
+                <div class="score-main">
+                    <span class="score-num">@_score</span>
+                    <span class="score-divider">/</span>
+                    <span class="score-total">@_totalQuestions</span>
+                </div>
+                <div class="score-percent">@((int)_percentage)% poprawnych odpowiedzi</div>
+            </div>
+
+            <button class="reset-quiz-btn" @onclick="CloseQuiz">
+                <span>ZAKOŃCZ</span>
+            </button>
+        </div>
+    }
     else if (QuizService.CurrentQuiz != null)
     {
         <div class="quiz-body">
@@ -41,17 +69,45 @@
             }
             
             <div class="quiz-footer">
-                <button class="submit-btn" disabled="@(!AllQuestionsAnswered())">Wyślij</button>
+                <button class="submit-btn" disabled="@(!AllQuestionsAnswered() || _isSubmitting)" @onclick="SubmitQuizAsync">
+                    @if (_isSubmitting)
+                    {
+                        <span>Zapisywanie...</span>
+                    }
+                    else
+                    {
+                        <span>Wyślij</span>
+                    }
+                </button>
             </div>
         </div>
     }
+    else
+    {
+        <div class="empty-quiz-state">
+            <div class="empty-icon-wrapper">
+                <NexusIcon Name="robot" Size="48" Class="neon-glow" />
+            </div>
+            <h3 class="empty-title">Brak Aktywnego Quizu</h3>
+            <p class="empty-text">Generuj spersonalizowany sprawdzian wiedzy na podstawie bieżącego rozdziału książki.</p>
+            
+            <button class="generate-quiz-btn" @onclick="GenerateChapterQuizAsync" disabled="@(string.IsNullOrWhiteSpace(Coordinator.CurrentFullPageContent))">
+                <span>GENERUJ QUIZ DLA ROZDZIAŁU</span>
+            </button>
+        </div>
+    }
 </div>
 
-
 @code {
     [Parameter] public string ContextBlockId { get; set; } = string.Empty;
 
     private Dictionary<QuizQuestionDto, (int SelectedIndex, bool IsCorrect)> _states = new();
+    private bool _isSubmitting = false;
+    private bool _isSubmitted = false;
+    private bool _isGenerating = false;
+    private int _score = 0;
+    private int _totalQuestions = 0;
+    private double _percentage = 0.0;
 
     protected override void OnInitialized()
     {
@@ -65,6 +121,24 @@
         QuizService.OnQuizUpdated -= HandleUpdate;
     }
 
+    private async Task GenerateChapterQuizAsync()
+    {
+        if (_isGenerating || string.IsNullOrWhiteSpace(Coordinator.CurrentFullPageContent)) return;
+
+        _isGenerating = true;
+        StateHasChanged();
+
+        try
+        {
+            await Coordinator.RequestSummaryAndQuizAsync(Coordinator.CurrentFullPageContent);
+        }
+        finally
+        {
+            _isGenerating = false;
+            StateHasChanged();
+        }
+    }
+
     private async Task SelectOptionAsync(QuizQuestionDto question, int index)
     {
         if (_states.ContainsKey(question)) return;
@@ -90,6 +164,67 @@
         return QuizService.CurrentQuiz != null && _states.Count == QuizService.CurrentQuiz.Questions.Count;
     }
 
+    private async Task SubmitQuizAsync()
+    {
+        if (QuizService.CurrentQuiz == null || !AllQuestionsAnswered() || _isSubmitting) return;
+
+        _isSubmitting = true;
+        StateHasChanged();
+
+        try
+        {
+            _score = _states.Values.Count(s => s.IsCorrect);
+            _totalQuestions = QuizService.CurrentQuiz.Questions.Count;
+            _percentage = _totalQuestions > 0 ? ((double)_score / _totalQuestions) * 100 : 0.0;
+
+            string topic = "Quiz wiedzy";
+            var graph = GraphService.CurrentGraphData;
+            if (graph != null && !string.IsNullOrEmpty(QuizService.CurrentQuizBlockId))
+            {
+                var node = graph.Nodes.FirstOrDefault(n => n.Id == QuizService.CurrentQuizBlockId);
+                if (node != null && !string.IsNullOrEmpty(node.Label))
+                {
+                    topic = $"Test: {node.Label}";
+                }
+            }
+
+            var profileResult = await IdentityService.GetProfileAsync();
+            if (profileResult.IsSuccess && profileResult.Value != null)
+            {
+                var userId = profileResult.Value.UserId;
+
+                var cmd = new SubmitQuizResultCommand(userId, topic, _score, _totalQuestions);
+                var result = await Mediator.Send(cmd);
+                
+                if (result.IsSuccess)
+                {
+                    IdentityService.ClearCache();
+                    _isSubmitted = true;
+                    await PlatformService.VibrateSuccessAsync();
+                }
+                else
+                {
+                    await PlatformService.VibrateErrorAsync();
+                }
+            }
+        }
+        catch
+        {
+            await PlatformService.VibrateErrorAsync();
+        }
+        finally
+        {
+            _isSubmitting = false;
+            StateHasChanged();
+        }
+    }
+
+    private void CloseQuiz()
+    {
+        _isSubmitted = false;
+        _states.Clear();
+        QuizService.SetQuiz(null, null);
+    }
 
     private string GetBlockClass(QuizQuestionDto question)
     {

src/NexusReader.UI.Shared/Components/Molecules/KnowledgeCheck.razor.css

@@ -121,3 +121,217 @@
     0% { background-position: -200% 0; }
     100% { background-position: 200% 0; }
 }
+
+.option-revealed-correct {
+    border-color: #00ff99 !important;
+    background: rgba(0, 255, 153, 0.08) !important;
+    box-shadow: 0 0 8px rgba(0, 255, 153, 0.15);
+}
+
+.option-faded {
+    opacity: 0.45;
+}
+
+.submitted-container {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    text-align: center;
+    padding: 2rem 1rem;
+    animation: fadeIn 0.4s ease-out;
+}
+
+.success-icon-wrapper {
+    background: rgba(0, 255, 153, 0.1);
+    border: 1px solid rgba(0, 255, 153, 0.3);
+    border-radius: 50%;
+    width: 80px;
+    height: 80px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    margin-bottom: 1.5rem;
+    box-shadow: 0 0 20px rgba(0, 255, 153, 0.15);
+}
+
+.success-glow {
+    color: var(--nexus-neon, #00ff99);
+    filter: drop-shadow(0 0 8px var(--nexus-neon, #00ff99));
+}
+
+.submitted-title {
+    font-size: 1.5rem;
+    font-weight: 700;
+    color: #fff;
+    margin-bottom: 0.5rem;
+    letter-spacing: -0.5px;
+}
+
+.submitted-text {
+    font-size: 0.9rem;
+    color: #888;
+    margin-bottom: 2rem;
+    line-height: 1.5;
+}
+
+.score-card {
+    background: rgba(255, 255, 255, 0.02);
+    border: 1px solid rgba(255, 255, 255, 0.05);
+    border-radius: 16px;
+    padding: 1.5rem 2.5rem;
+    margin-bottom: 2rem;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    backdrop-filter: blur(10px);
+}
+
+.score-main {
+    display: flex;
+    align-items: baseline;
+    gap: 0.2rem;
+    margin-bottom: 0.5rem;
+}
+
+.score-num {
+    font-size: 3rem;
+    font-weight: 800;
+    color: var(--nexus-neon, #00ff99);
+    line-height: 1;
+    text-shadow: 0 0 15px rgba(0, 255, 153, 0.3);
+}
+
+.score-divider {
+    font-size: 1.8rem;
+    color: #444;
+}
+
+.score-total {
+    font-size: 1.8rem;
+    font-weight: 600;
+    color: #fff;
+}
+
+.score-percent {
+    font-size: 0.85rem;
+    color: #666;
+    text-transform: uppercase;
+    letter-spacing: 1px;
+}
+
+.reset-quiz-btn {
+    padding: 0.8rem 3rem;
+    background: transparent;
+    border: 1px solid rgba(255, 255, 255, 0.15);
+    border-radius: 30px;
+    color: #fff;
+    font-size: 0.9rem;
+    font-weight: 600;
+    cursor: pointer;
+    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+    letter-spacing: 0.5px;
+}
+
+.reset-quiz-btn:hover {
+    background: rgba(255, 255, 255, 0.05);
+    border-color: #fff;
+    box-shadow: 0 0 15px rgba(255, 255, 255, 0.1);
+}
+
+@keyframes fadeIn {
+    from {
+        opacity: 0;
+        transform: translateY(10px);
+    }
+    to {
+        opacity: 1;
+        transform: translateY(0);
+    }
+}
+
+.empty-quiz-state {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    text-align: center;
+    padding: 2.5rem 1rem;
+    animation: fadeIn 0.4s ease-out;
+}
+
+.empty-icon-wrapper {
+    background: rgba(0, 255, 153, 0.03);
+    border: 1px solid rgba(0, 255, 153, 0.15);
+    border-radius: 50%;
+    width: 80px;
+    height: 80px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    margin-bottom: 1.5rem;
+    box-shadow: 0 0 30px rgba(0, 255, 153, 0.05);
+    transition: all 0.3s ease;
+}
+
+.empty-quiz-state:hover .empty-icon-wrapper {
+    background: rgba(0, 255, 153, 0.08);
+    border-color: rgba(0, 255, 153, 0.4);
+    box-shadow: 0 0 35px rgba(0, 255, 153, 0.15);
+    transform: scale(1.05);
+}
+
+.neon-glow {
+    color: var(--nexus-neon, #00ff99);
+    filter: drop-shadow(0 0 6px var(--nexus-neon, #00ff99));
+}
+
+.empty-title {
+    font-size: 1.3rem;
+    font-weight: 700;
+    color: #fff;
+    margin-bottom: 0.5rem;
+    letter-spacing: -0.3px;
+}
+
+.empty-text {
+    font-size: 0.9rem;
+    color: #888;
+    margin-bottom: 2rem;
+    line-height: 1.5;
+    max-width: 280px;
+}
+
+.generate-quiz-btn {
+    padding: 0.85rem 2rem;
+    background: rgba(0, 255, 153, 0.08);
+    border: 1px solid var(--nexus-neon, #00ff99);
+    border-radius: 30px;
+    color: var(--nexus-neon, #00ff99);
+    font-size: 0.85rem;
+    font-weight: 700;
+    cursor: pointer;
+    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+    letter-spacing: 0.8px;
+    text-shadow: 0 0 10px rgba(0, 255, 153, 0.3);
+    box-shadow: 0 0 15px rgba(0, 255, 153, 0.1);
+}
+
+.generate-quiz-btn:not(:disabled):hover {
+    background: var(--nexus-neon, #00ff99);
+    color: #000;
+    box-shadow: 0 0 25px rgba(0, 255, 153, 0.4);
+    transform: translateY(-2px);
+    text-shadow: none;
+}
+
+.generate-quiz-btn:disabled {
+    opacity: 0.4;
+    cursor: not-allowed;
+    border-color: rgba(255, 255, 255, 0.15);
+    background: rgba(255, 255, 255, 0.02);
+    color: #666;
+    text-shadow: none;
+    box-shadow: none;
+}
+

src/NexusReader.UI.Shared/Components/Organisms/BookIngestionModal.razor

@@ -2,12 +2,14 @@
 @using NexusReader.Application.Abstractions.Services
 @using NexusReader.Application.Queries.Reader
 @using NexusReader.Application.Commands.Library
+@using NexusReader.UI.Shared.Services
 @using System.Net.Http.Json
 @inject IEpubMetadataExtractor MetadataExtractor
 @inject ILogger<BookIngestionModal> Logger
 @inject HttpClient Http
 @inject IReaderNavigationService ReaderNavigation
 @inject IJSRuntime JSRuntime
+@inject ISyncService SyncService
 @implements IAsyncDisposable
 
 @if (IsOpen)
@@ -16,20 +18,23 @@
         <div class="modal-content glass-panel" @onclick:stopPropagation>
             <div class="modal-header">
                 <h2>Add New Book</h2>
-                <button class="close-btn" @onclick="CloseModal">
-                    <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="18" y1="6" x2="6" y2="18"></line><line x1="6" y1="6" x2="18" y2="18"></line></svg>
-                </button>
+                @if (!IsIngesting && !IsIndexing)
+                {
+                    <button class="close-btn" @onclick="CloseModal">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><line x1="18" y1="6" x2="6" y2="18"></line><line x1="6" y1="6" x2="18" y2="18"></line></svg>
+                    </button>
+                }
             </div>
 
             <div class="modal-body">
-                <div class="parsing-state shimmer" style="@(IsParsing ? "display:flex;" : "display:none;")">
+                <div class="parsing-state shimmer" style="@(IsParsing && !IsIndexing ? "display:flex;" : "display:none;")">
                     <div class="shimmer-content">
                         <div class="spinner"></div>
                         <p>Scanning metadata...</p>
                     </div>
                 </div>
                 
-                <div class="verification-state" style="@(IsVerifying && !IsParsing ? "display:flex;" : "display:none;")">
+                <div class="verification-state" style="@(IsVerifying && !IsParsing && !IsIndexing ? "display:flex;" : "display:none;")">
                     @if (Metadata != null)
                     {
                         <div class="verification-layout">
@@ -74,7 +79,7 @@
                 </div>
                 
                 <div class="upload-state @(_isDragging ? "drag-over" : "")" 
-                     style="@(!IsParsing && !IsVerifying ? "display:flex;" : "display:none;")"
+                     style="@(!IsParsing && !IsVerifying && !IsIndexing ? "display:flex;" : "display:none;")"
                      @ondragenter="OnDragEnter" 
                      @ondragleave="OnDragLeave">
                     <div class="drop-zone">
@@ -87,6 +92,18 @@
                     </div>
                 </div>
 
+                <div class="indexing-state" style="@(IsIndexing ? "display:flex;" : "display:none;")">
+                    <div class="indexing-content">
+                        <div class="spinner"></div>
+                        <h3>Nexus AI Indexing</h3>
+                        <p class="status-msg">@IngestionStatusMessage</p>
+                        <div class="progress-bar-container">
+                            <div class="progress-bar-fill" style="width: @((IngestionProgressPercent * 100).ToString("F0"))%"></div>
+                        </div>
+                        <span class="percent">@((IngestionProgressPercent * 100).ToString("F0"))%</span>
+                    </div>
+                </div>
+
                 
                 @if (!string.IsNullOrEmpty(ErrorMessage))
                 {
@@ -118,6 +135,10 @@
     private bool IsParsing { get; set; }
     private bool IsVerifying { get; set; }
     private bool IsIngesting { get; set; }
+    private bool IsIndexing { get; set; }
+    private string IngestionStatusMessage { get; set; } = "Initializing...";
+    private double IngestionProgressPercent { get; set; }
+    private Guid IngestedBookId { get; set; } = Guid.Empty;
     private LocalEpubMetadata? Metadata { get; set; }
     private string? ErrorMessage { get; set; }
     private byte[]? _epubBytes;
@@ -125,8 +146,42 @@
     // Allow up to 50 MB
     private const long MaxFileSize = 50 * 1024 * 1024;
 
+    protected override async Task OnInitializedAsync()
+    {
+        await SyncService.InitializeAsync();
+        SyncService.OnIngestionProgressReceived += HandleIngestionProgress;
+    }
+
+    private async Task HandleIngestionProgress(string message, double progress)
+    {
+        if (!IsIndexing) return;
+
+        IngestionStatusMessage = message;
+        IngestionProgressPercent = progress;
+        
+        await InvokeAsync(StateHasChanged);
+
+        if (progress >= 1.0)
+        {
+            // Give the user a moment to see the completion message
+            await Task.Delay(2500);
+            
+            // Now close the modal and navigate to the book
+            if (IngestedBookId != Guid.Empty)
+            {
+                var bookId = IngestedBookId;
+                await InvokeAsync(async () => {
+                    await CloseModal();
+                    ReaderNavigation.NavigateToBook(bookId);
+                });
+            }
+        }
+    }
+
     private async Task CloseModal()
     {
+        if (IsIngesting || IsIndexing) return;
+
         IsOpen = false;
         Reset();
         await IsOpenChanged.InvokeAsync(false);
@@ -137,6 +192,10 @@
         IsParsing = false;
         IsVerifying = false;
         IsIngesting = false;
+        IsIndexing = false;
+        IngestionStatusMessage = "Initializing...";
+        IngestionProgressPercent = 0.0;
+        IngestedBookId = Guid.Empty;
         Metadata = null;
         ErrorMessage = null;
         _isDragging = false;
@@ -220,33 +279,40 @@
                 var result = await response.Content.ReadFromJsonAsync<IngestResult>();
                 if (result != null)
                 {
-                    await CloseModal();
-                    ReaderNavigation.NavigateToBook(result.Id);
+                    IngestedBookId = result.Id;
+                    IsVerifying = false;
+                    IsIngesting = false;
+                    IsIndexing = true;
+                    IngestionStatusMessage = "Book saved! Starting background indexing...";
+                    IngestionProgressPercent = 0.0;
+                    StateHasChanged();
                 }
             }
             else
             {
                 ErrorMessage = await response.Content.ReadAsStringAsync();
+                IsIngesting = false;
             }
         }
         catch (Exception ex)
         {
             Logger.LogError(ex, "Error during ingestion");
             ErrorMessage = "Failed to save book to library. Please try again.";
+            IsIngesting = false;
         }
         finally
         {
-            IsIngesting = false;
             StateHasChanged();
         }
     }
 
     private record IngestResult(Guid Id);
 
-    public ValueTask DisposeAsync()
+    public async ValueTask DisposeAsync()
     {
+        SyncService.OnIngestionProgressReceived -= HandleIngestionProgress;
         // Clear the large byte array so it is eligible for GC even if the component is cached.
         _epubBytes = null;
-        return ValueTask.CompletedTask;
+        await ValueTask.CompletedTask;
     }
 }

src/NexusReader.UI.Shared/Components/Organisms/BookIngestionModal.razor.css

@@ -377,6 +377,72 @@
     animation: spin 0.8s linear infinite;
 }
 
+/* Indexing State */
+.indexing-state {
+    flex: 1;
+    display: flex;
+    justify-content: center;
+    align-items: center;
+    border-radius: 12px;
+    background: rgba(255, 255, 255, 0.02);
+    border: 1px solid rgba(255, 255, 255, 0.05);
+    box-shadow: inset 0 0 12px rgba(255, 255, 255, 0.02);
+    position: relative;
+    overflow: hidden;
+    padding: 2rem;
+    animation: fadeIn 0.4s ease-out;
+}
+
+.indexing-content {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    text-align: center;
+    width: 100%;
+    gap: 1.25rem;
+}
+
+.indexing-content h3 {
+    margin: 0;
+    font-size: 1.25rem;
+    color: var(--nexus-neon, #00ffaa);
+    text-shadow: 0 0 10px rgba(0, 255, 153, 0.2);
+    letter-spacing: 0.5px;
+}
+
+.status-msg {
+    margin: 0;
+    font-size: 0.9rem;
+    color: var(--nexus-text-muted, #888);
+    min-height: 2.5rem;
+    line-height: 1.4;
+}
+
+.progress-bar-container {
+    width: 100%;
+    height: 8px;
+    background: rgba(255, 255, 255, 0.05);
+    border-radius: 4px;
+    overflow: hidden;
+    position: relative;
+    border: 1px solid rgba(255, 255, 255, 0.05);
+}
+
+.progress-bar-fill {
+    height: 100%;
+    background: linear-gradient(90deg, var(--nexus-neon, #00ffaa) 0%, #00b3ff 100%);
+    box-shadow: 0 0 10px rgba(0, 255, 153, 0.4);
+    border-radius: 4px;
+    transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.percent {
+    font-family: var(--nexus-font-mono, monospace);
+    font-size: 1.1rem;
+    font-weight: 700;
+    color: var(--nexus-text);
+}
+
 @keyframes fadeIn {
     from { opacity: 0; }
     to { opacity: 1; }

src/NexusReader.UI.Shared/Components/Organisms/ReaderCanvas.razor

@@ -67,6 +67,7 @@
     private bool _isJsInitialized;
     private ElementReference _containerRef;
     private bool _isInteractive;
+    private string? _currentActiveBlockId;
 
     protected override async Task OnInitializedAsync()
     {
@@ -143,6 +144,7 @@
     [JSInvokable]
     public async Task HandleBlockReached(string blockId, string content)
     {
+        _currentActiveBlockId = blockId;
         await Coordinator.OnBlockReachedAsync(blockId, content);
 
         if (ViewModel != null)
@@ -160,8 +162,15 @@
 
     private async Task HandleSyncProgressReceived(string blockId, DateTime timestamp)
     {
+        if (string.IsNullOrEmpty(blockId) || blockId == _currentActiveBlockId)
+        {
+            Logger.LogDebug("[Sync] Received progress {BlockId} is empty or matches active block. Ignoring scroll.", blockId);
+            return;
+        }
+
         Logger.LogInformation("[Sync] Received progress from another device: block {BlockId} at {Timestamp}", blockId, timestamp);
 
+        _currentActiveBlockId = blockId;
         await ScrollToNodeAsync(blockId);
         await InvokeAsync(StateHasChanged);
     }
@@ -211,6 +220,8 @@
 
     private async Task LoadChapterAsync(int index)
     {
+        await Coordinator.ClearAsync();
+        _isJsInitialized = false; // Reset JS initialization to re-bind the scroll observer to new DOM elements!
         _isLoadingChapter = true;
         StatusMessage = "Wczytywanie treści...";
         StateHasChanged();
@@ -252,6 +263,7 @@
         {
             var targetBlockId = NavigationService.PendingScrollBlockId;
             NavigationService.PendingScrollBlockId = null; // Clear it to prevent multiple scrolls
+            _currentActiveBlockId = targetBlockId;
 
             // Give the browser slightly more than one frame to render the loaded blocks
             await Task.Delay(150);

src/NexusReader.UI.Shared/Layout/ReaderLayout.razor

@@ -3,10 +3,13 @@
 @using NexusReader.UI.Shared.Services
 @using NexusReader.UI.Shared.Components.Molecules
 @using NexusReader.UI.Shared.Components.Organisms
+@using NexusReader.Application.Queries.Graph
 @using Microsoft.Extensions.Logging
 @inject IPlatformService PlatformService
 @inject IFocusModeService FocusMode
 @inject IQuizStateService QuizService
+@inject IReaderInteractionService InteractionService
+@inject IKnowledgeGraphService GraphService
 @inject IJSRuntime JS
 @inject IIdentityService IdentityService
 @inject NavigationManager NavigationManager
@@ -41,13 +44,92 @@
                         <button class="close-btn">×</button>
                     </div>
 
-                    <div class="intelligence-scroll-area">
-                        @if (!_isMobile)
-                        {
-                            <KnowledgeGraph />
-                        }
-                        <KnowledgeCheck />
-                    </div>
+                    @if (_activeTab == SidebarTab.Knowledge)
+                    {
+                        <div class="intelligence-scroll-area stacked-layout">
+                            @if (!_isMobile)
+                            {
+                                <div class="visual-workspace">
+                                    <KnowledgeGraph />
+                                </div>
+                            }
+                            
+                            <div class="contextual-intelligence-panel">
+                                <div class="panel-header">
+                                    <NexusIcon Name="brain" Size="18" Class="neon-accent-icon" />
+                                    <span class="panel-title">Contextual Intelligence Panel</span>
+                                </div>
+                                <div class="panel-body">
+                                    @if (_selectedNode != null)
+                                    {
+                                        <div class="node-details">
+                                            <div class="node-header-section">
+                                                <span class="node-group-badge @(_selectedNode.Group.ToLower())">@(_selectedNode.Group.ToUpper())</span>
+                                                <h3 class="node-label">@_selectedNode.Label</h3>
+                                            </div>
+                                            
+                                            @if (!string.IsNullOrEmpty(_selectedNode.Description))
+                                            {
+                                                <div class="detail-section">
+                                                    <p class="node-description">@_selectedNode.Description</p>
+                                                </div>
+                                            }
+
+                                            @if (!string.IsNullOrEmpty(_selectedNode.Summary))
+                                            {
+                                                <div class="detail-section summary-section">
+                                                    <h4 class="section-title neon-sub-header">Podsumowanie</h4>
+                                                    <p class="node-summary">@_selectedNode.Summary</p>
+                                                </div>
+                                            }
+
+                                            @if (_selectedNode.KeyTerms != null && _selectedNode.KeyTerms.Any())
+                                            {
+                                                <div class="detail-section key-terms-section">
+                                                    <h4 class="section-title neon-sub-header">Kluczowe Pojęcia</h4>
+                                                    <ul class="key-terms-list">
+                                                        @foreach (var term in _selectedNode.KeyTerms)
+                                                        {
+                                                            <li class="key-term-item">
+                                                                <span class="term-bullet">•</span>
+                                                                <span class="term-text">@term</span>
+                                                            </li>
+                                                        }
+                                                    </ul>
+                                                </div>
+                                            }
+                                        </div>
+                                    }
+                                    else
+                                    {
+                                        <div class="no-node-selected">
+                                            <div class="placeholder-glow"></div>
+                                            <p class="placeholder-text">Wybierz węzeł na wykresie, aby wyświetlić szczegóły architektoniczne.</p>
+                                        </div>
+                                    }
+                                </div>
+                            </div>
+                        </div>
+
+                        <div class="sidebar-footer">
+                            <button class="open-quiz-btn neon-glow-btn @(QuizService.HasNewQuiz ? "quiz-pulse-btn" : "")" @onclick="() => SetActiveTab(SidebarTab.Quiz)">
+                                <NexusIcon Name="quiz" Size="18" />
+                                <span>OPEN KNOWLEDGE QUIZ</span>
+                            </button>
+                        </div>
+                    }
+                    else
+                    {
+                        <div class="intelligence-scroll-area quiz-layout">
+                            <div class="quiz-nav">
+                                <button class="back-to-graph-btn" @onclick="() => SetActiveTab(SidebarTab.Knowledge)">
+                                    <NexusIcon Name="arrow-left" Size="16" />
+                                    <span>← Powrót do wykresu</span>
+                                </button>
+                            </div>
+                            <KnowledgeCheck />
+                        </div>
+                    }
                 </div>
             </div>
         </Authorized>
@@ -67,6 +149,16 @@
 </div>
 
 @code {
+    private enum SidebarTab
+    {
+        Knowledge,
+        Quiz
+    }
+
+    private SidebarTab _activeTab = SidebarTab.Knowledge;
+    private string? _selectedNodeId;
+    private GraphNodeDto? _selectedNode;
+
     private string _platformClass = "platform-desktop";
     private bool _isMobile = false;
 
@@ -74,6 +166,10 @@
     {
         FocusMode.OnFocusModeChanged += HandleUpdate;
         QuizService.OnQuizUpdated += HandleUpdate;
+        QuizService.OnQuizRequested += HandleQuizRequestedAsync;
+
+        InteractionService.OnNodeSelected += HandleNodeSelectedAsync;
+        GraphService.OnGraphUpdated += HandleGraphUpdatedAsync;
 
         var context = PlatformService.GetDeviceContext();
         if (context.IsSuccess)
@@ -88,7 +184,34 @@
         }
     }
 
+    private void SetActiveTab(SidebarTab tab)
+    {
+        _activeTab = tab;
+        StateHasChanged();
+    }
 
+    private async Task HandleQuizRequestedAsync(string blockId)
+    {
+        _activeTab = SidebarTab.Quiz;
+        await InvokeAsync(StateHasChanged);
+    }
+
+    private async Task HandleNodeSelectedAsync(string nodeId)
+    {
+        _selectedNodeId = nodeId;
+        if (GraphService.CurrentGraphData != null)
+        {
+            _selectedNode = GraphService.CurrentGraphData.Nodes.FirstOrDefault(n => n.Id == nodeId);
+        }
+        await InvokeAsync(StateHasChanged);
+    }
+
+    private async Task HandleGraphUpdatedAsync()
+    {
+        _selectedNodeId = null;
+        _selectedNode = null;
+        await InvokeAsync(StateHasChanged);
+    }
 
     protected override async Task OnAfterRenderAsync(bool firstRender)
     {
@@ -112,5 +235,8 @@
     {
         FocusMode.OnFocusModeChanged -= HandleUpdate;
         QuizService.OnQuizUpdated -= HandleUpdate;
+        QuizService.OnQuizRequested -= HandleQuizRequestedAsync;
+        InteractionService.OnNodeSelected -= HandleNodeSelectedAsync;
+        GraphService.OnGraphUpdated -= HandleGraphUpdatedAsync;
     }
 }

src/NexusReader.UI.Shared/Layout/ReaderLayout.razor.css

@@ -152,4 +152,319 @@ main {
     0% { filter: drop-shadow(0 0 2px var(--nexus-neon)); transform: scale(1); }
     50% { filter: drop-shadow(0 0 10px var(--nexus-neon)); transform: scale(1.1); }
     100% { filter: drop-shadow(0 0 2px var(--nexus-neon)); transform: scale(1); }
+}
+
+/* Contextual Intelligence Panel Layout */
+.stacked-layout {
+    display: flex;
+    flex-direction: column;
+    height: 100%;
+}
+
+.visual-workspace {
+    flex-shrink: 0;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
+}
+
+.contextual-intelligence-panel {
+    flex: 1;
+    display: flex;
+    flex-direction: column;
+    background: rgba(13, 13, 13, 0.6);
+    border-top: 1px solid rgba(255, 255, 255, 0.03);
+    overflow: hidden;
+}
+
+.panel-header {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    padding: 0.75rem 1.25rem;
+    background: rgba(255, 255, 255, 0.01);
+    border-bottom: 1px solid rgba(255, 255, 255, 0.03);
+}
+
+.neon-accent-icon {
+    color: var(--nexus-neon, #00f0ff);
+    filter: drop-shadow(0 0 5px var(--nexus-neon, #00f0ff));
+}
+
+.panel-title {
+    font-family: var(--nexus-font-sans, "Outfit", sans-serif);
+    font-size: 0.75rem;
+    text-transform: uppercase;
+    letter-spacing: 0.1em;
+    color: rgba(255, 255, 255, 0.5);
+    font-weight: 600;
+}
+
+.panel-body {
+    flex: 1;
+    overflow-y: auto;
+    padding: 1.25rem;
+}
+
+.no-node-selected {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    height: 100%;
+    min-height: 150px;
+    text-align: center;
+    color: rgba(255, 255, 255, 0.35);
+    padding: 2rem;
+}
+
+.placeholder-glow {
+    width: 48px;
+    height: 48px;
+    border-radius: 50%;
+    background: radial-gradient(circle, rgba(0, 240, 255, 0.15) 0%, transparent 70%);
+    animation: glow-pulse 2s infinite ease-in-out;
+    margin-bottom: 1rem;
+}
+
+@keyframes glow-pulse {
+    0% { transform: scale(0.9); opacity: 0.5; }
+    50% { transform: scale(1.1); opacity: 1; }
+    100% { transform: scale(0.9); opacity: 0.5; }
+}
+
+.placeholder-text {
+    font-size: 0.85rem;
+    line-height: 1.4;
+    font-weight: 300;
+}
+
+.node-details {
+    display: flex;
+    flex-direction: column;
+    gap: 1.25rem;
+    animation: fade-in 0.3s ease-out;
+}
+
+@keyframes fade-in {
+    from { opacity: 0; transform: translateY(5px); }
+    to { opacity: 1; transform: translateY(0); }
+}
+
+.node-header-section {
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
+    padding-bottom: 0.75rem;
+}
+
+.node-group-badge {
+    align-self: flex-start;
+    font-size: 0.65rem;
+    font-weight: 700;
+    padding: 0.15rem 0.5rem;
+    border-radius: 4px;
+    letter-spacing: 0.08em;
+    border: 1px solid transparent;
+}
+
+/* Badge specific styling matching category theme colors */
+.node-group-badge.rule {
+    background: rgba(244, 63, 94, 0.1);
+    color: #f43f5e;
+    border-color: rgba(244, 63, 94, 0.3);
+}
+
+.node-group-badge.definition {
+    background: rgba(234, 179, 8, 0.1);
+    color: #eab308;
+    border-color: rgba(234, 179, 8, 0.3);
+}
+
+.node-group-badge.table {
+    background: rgba(168, 85, 247, 0.1);
+    color: #a855f7;
+    border-color: rgba(168, 85, 247, 0.3);
+}
+
+.node-group-badge.section {
+    background: rgba(59, 130, 246, 0.1);
+    color: #3b82f6;
+    border-color: rgba(59, 130, 246, 0.3);
+}
+
+.node-group-badge.bridge {
+    background: rgba(236, 72, 153, 0.1);
+    color: #ec4899;
+    border-color: rgba(236, 72, 153, 0.3);
+}
+
+.node-group-badge.current {
+    background: rgba(16, 185, 129, 0.1);
+    color: #10b981;
+    border-color: rgba(16, 185, 129, 0.3);
+}
+
+.node-group-badge.concept {
+    background: rgba(0, 240, 255, 0.1);
+    color: #00f0ff;
+    border-color: rgba(0, 240, 255, 0.3);
+}
+
+.node-label {
+    font-family: var(--nexus-font-sans, "Outfit", sans-serif);
+    font-size: 1.15rem;
+    font-weight: 600;
+    color: #ffffff;
+    margin: 0;
+}
+
+.detail-section {
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+}
+
+.section-title {
+    font-size: 0.7rem;
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 0.08em;
+    margin: 0;
+    color: rgba(255, 255, 255, 0.4);
+}
+
+.neon-sub-header {
+    border-left: 2px solid var(--nexus-neon, #00f0ff);
+    padding-left: 0.5rem;
+    text-shadow: 0 0 10px rgba(0, 240, 255, 0.2);
+}
+
+.node-description {
+    font-size: 0.85rem;
+    line-height: 1.5;
+    color: rgba(255, 255, 255, 0.85);
+    margin: 0;
+}
+
+.node-summary {
+    font-size: 0.82rem;
+    line-height: 1.5;
+    color: rgba(255, 255, 255, 0.75);
+    background: rgba(255, 255, 255, 0.02);
+    border-left: 2px solid rgba(255, 255, 255, 0.1);
+    padding: 0.5rem 0.75rem;
+    border-radius: 0 4px 4px 0;
+    margin: 0;
+}
+
+.key-terms-list {
+    list-style: none;
+    padding: 0;
+    margin: 0;
+    display: flex;
+    flex-direction: column;
+    gap: 0.4rem;
+}
+
+.key-term-item {
+    display: flex;
+    align-items: flex-start;
+    gap: 0.5rem;
+    font-size: 0.82rem;
+    color: rgba(255, 255, 255, 0.8);
+}
+
+.term-bullet {
+    color: var(--nexus-neon, #00f0ff);
+    filter: drop-shadow(0 0 3px var(--nexus-neon, #00f0ff));
+    font-weight: bold;
+}
+
+.term-text {
+    line-height: 1.4;
+}
+
+/* Sidebar Footer & Open Quiz Button */
+.sidebar-footer {
+    padding: 1rem 1.25rem;
+    background: rgba(13, 13, 13, 0.95);
+    border-top: 1px solid rgba(255, 255, 255, 0.05);
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+    z-index: 10;
+}
+
+.open-quiz-btn {
+    width: 100%;
+    padding: 0.75rem 1rem;
+    border-radius: 8px;
+    font-family: var(--nexus-font-sans, "Outfit", sans-serif);
+    font-size: 0.75rem;
+    font-weight: 700;
+    letter-spacing: 0.12em;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 0.6rem;
+    cursor: pointer;
+    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+    background: rgba(0, 240, 255, 0.03);
+    border: 1px solid rgba(0, 240, 255, 0.3);
+    color: var(--nexus-neon, #00f0ff);
+    box-shadow: 0 4px 15px rgba(0, 240, 255, 0.05);
+}
+
+.open-quiz-btn:hover {
+    background: rgba(0, 240, 255, 0.1);
+    border-color: var(--nexus-neon, #00f0ff);
+    color: #ffffff;
+    box-shadow: 0 0 20px rgba(0, 240, 255, 0.25);
+    transform: translateY(-2px);
+}
+
+.open-quiz-btn:active {
+    transform: translateY(0);
+}
+
+.quiz-pulse-btn {
+    animation: quiz-pulse-glow 2s infinite ease-in-out;
+}
+
+@keyframes quiz-pulse-glow {
+    0% { border-color: rgba(0, 240, 255, 0.3); box-shadow: 0 0 5px rgba(0, 240, 255, 0.1); }
+    50% { border-color: var(--nexus-neon, #00f0ff); box-shadow: 0 0 25px rgba(0, 240, 255, 0.3); }
+    100% { border-color: rgba(0, 240, 255, 0.3); box-shadow: 0 0 5px rgba(0, 240, 255, 0.1); }
+}
+
+/* Quiz Navigation Header */
+.quiz-layout {
+    display: flex;
+    flex-direction: column;
+}
+
+.quiz-nav {
+    padding: 0.75rem 1.25rem;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
+    background: rgba(255, 255, 255, 0.01);
+}
+
+.back-to-graph-btn {
+    background: none;
+    border: none;
+    color: rgba(255, 255, 255, 0.5);
+    font-size: 0.8rem;
+    font-weight: 500;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    padding: 0.25rem 0.5rem;
+    border-radius: 4px;
+    transition: all 0.2s;
+}
+
+.back-to-graph-btn:hover {
+    color: var(--nexus-neon, #00f0ff);
+    background: rgba(255, 255, 255, 0.02);
 }

src/NexusReader.UI.Shared/Pages/Dashboard.razor

@@ -5,7 +5,10 @@
 @using NexusReader.UI.Shared.Services
 @inject IIdentityService IdentityService
 @inject NavigationManager NavigationManager
+@inject ISyncService SyncService
 @attribute [Authorize]
+@implements IDisposable
+
 
 <PageTitle>Dashboard | Nexus Reader</PageTitle>
 
@@ -18,20 +21,20 @@
                 <img src="https://api.dicebear.com/7.x/bottts/svg?seed=Nexus" alt="Profile" class="profile-img" />
                 <div class="avatar-glow"></div>
             </div>
-            <h1 class="username">[User_Explorer1988]</h1>
+            <h1 class="username">@(string.IsNullOrEmpty(_profile?.DisplayName) ? (_profile?.Email.Split('@')[0] ?? "Użytkownik") : _profile.DisplayName)</h1>
             
             <div class="status-pills">
                 <div class="status-pill">
-                    <span class="pill-label">Books Read:</span>
-                    <span class="pill-value">12</span>
+                    <span class="pill-label">Książki:</span>
+                    <span class="pill-value">@(_profile?.BooksReadCount ?? 0)</span>
                 </div>
                 <div class="status-pill">
-                    <span class="pill-label">Concepts Mapped:</span>
-                    <span class="pill-value">450</span>
+                    <span class="pill-label">Pojęcia:</span>
+                    <span class="pill-value">@(_profile?.ConceptsMappedCount ?? 0)</span>
                 </div>
                 <div class="status-pill">
-                    <span class="pill-label">Quiz Mastery:</span>
-                    <span class="pill-value">88%</span>
+                    <span class="pill-label">Średni Wynik:</span>
+                    <span class="pill-value">@(_profile?.AverageQuizScore ?? 0)%</span>
                 </div>
             </div>
         </div>
@@ -39,7 +42,7 @@
 
     <!-- Main Content Area -->
     <main class="dashboard-content">
-        <h2 class="section-title">Witaj, @(_profile?.Email.Split('@')[0] ?? "Użytkowniku")</h2>
+        <h2 class="section-title">Witaj, @(string.IsNullOrEmpty(_profile?.DisplayName) ? (_profile?.Email.Split('@')[0] ?? "Użytkowniku") : _profile.DisplayName)</h2>
         
         <div class="main-grid">
             <!-- Current Reading Card -->
@@ -49,34 +52,88 @@
                 <!-- Knowledge Integration -->
                 <section class="integration-card glass-panel">
                     <div class="panel-header">
-                        <h4>Knowledge Integration Progress</h4>
+                        <h4>Integracja Wiedzy</h4>
                         <NexusIcon Name="arrow-right" Size="16" />
                     </div>
                     <div class="graph-placeholder">
-                        <div class="graph-node central"></div>
-                        <div class="graph-node satellite" style="--angle: 0deg; --dist: 60px;"></div>
-                        <div class="graph-node satellite" style="--angle: 120deg; --dist: 50px;"></div>
-                        <div class="graph-node satellite" style="--angle: 240deg; --dist: 70px;"></div>
-                        <div class="active-node-label">TU JESTEŚ</div>
+                        <div class="graph-node central" title="Ośrodek Wiedzy Nexus Reader"></div>
+                        
+                        @if (_profile?.MappedConcepts != null && _profile.MappedConcepts.Any())
+                        {
+                            @for (int i = 0; i < _profile.MappedConcepts.Count; i++)
+                            {
+                                var concept = _profile.MappedConcepts[i];
+                                var angle = i * (360.0 / _profile.MappedConcepts.Count);
+                                var dist = 65;
+                                <div class="graph-node satellite" 
+                                     style="--angle: @(angle)deg; --dist: @(dist)px;"
+                                     title="[@concept.Type] @concept.Content"
+                                     @onmouseover="() => SetHoveredConcept(concept)"
+                                     @onmouseout="ClearHoveredConcept">
+                                </div>
+                            }
+                        }
+                        else
+                        {
+                            <div class="graph-node satellite" style="--angle: 0deg; --dist: 60px;"></div>
+                            <div class="graph-node satellite" style="--angle: 120deg; --dist: 50px;"></div>
+                            <div class="graph-node satellite" style="--angle: 240deg; --dist: 70px;"></div>
+                        }
+                        
+                        <div class="active-node-label">
+                            @(string.IsNullOrEmpty(_hoveredConceptLabel) ? "TU JESTEŚ" : _hoveredConceptLabel)
+                        </div>
                     </div>
+                    
+                    @if (_hoveredConcept != null)
+                    {
+                        <div class="concept-detail-toast">
+                            <span class="concept-type">@_hoveredConcept.Type</span>
+                            <p class="concept-content">@_hoveredConcept.Content</p>
+                        </div>
+                    }
+                    else
+                    {
+                        <div class="concept-detail-toast placeholder">
+                            <span class="concept-type">Mapowanie AI</span>
+                            <p class="concept-content">Najedź na węzeł, aby zbadać pojęcie wydobyte przez Nexus AI.</p>
+                        </div>
+                    }
                 </section>
 
                 <!-- Quiz Summary -->
                 <section class="quiz-card glass-panel">
                     <div class="panel-header">
-                        <h4>Quiz Summary: Key Thinkers</h4>
+                        <h4>Rozwiązane Quizy</h4>
                         <NexusIcon Name="arrow-right" Size="16" />
                     </div>
                     <div class="quiz-preview">
-                        <p class="question">Który artysta namalował 'Ostatnią Wieczerzę'?</p>
-                        <div class="quiz-options">
-                            <div class="quiz-option active">
-                                <span class="option-letter">A)</span> Michal Anioł
+                        @if (_profile?.RecentQuizzes != null && _profile.RecentQuizzes.Any())
+                        {
+                            <div class="quiz-history-list">
+                                @foreach (var quiz in _profile.RecentQuizzes)
+                                {
+                                    <div class="quiz-history-item">
+                                        <div class="quiz-item-header">
+                                            <span class="quiz-topic">@quiz.Topic</span>
+                                            <span class="quiz-score badge @(quiz.Percentage >= 80 ? "badge-success" : quiz.Percentage >= 50 ? "badge-warning" : "badge-danger")">
+                                                @quiz.Score / @quiz.TotalQuestions (@((int)quiz.Percentage)%)
+                                            </span>
+                                        </div>
+                                        <div class="quiz-item-meta">
+                                            <span class="quiz-date">@quiz.CompletedDate.ToString("g")</span>
+                                        </div>
+                                    </div>
+                                }
                             </div>
-                            <div class="quiz-option">
-                                <span class="option-letter">B)</span> Leonardo da Vinci
+                        }
+                        else
+                        {
+                            <div class="empty-quiz-state">
+                                <p class="question">Brak rozwiązanych quizów</p>
+                                <p class="sub-text">Rozwiązuj quizy w trakcie czytania książek, aby śledzić swoje postępy.</p>
                             </div>
-                        </div>
+                        }
                     </div>
                 </section>
             </div>
@@ -86,13 +143,65 @@
 
 @code {
     private UserProfileDto? _profile;
+    private MappedConceptDto? _hoveredConcept;
+    private string _hoveredConceptLabel = string.Empty;
 
     protected override async Task OnInitializedAsync()
+    {
+        IdentityService.OnStateInvalidated += HandleStateInvalidatedAsync;
+        await LoadProfileAsync();
+        
+        await SyncService.InitializeAsync();
+        SyncService.OnProgressReceived += HandleProgressReceivedAsync;
+    }
+
+    private void SetHoveredConcept(MappedConceptDto concept)
+    {
+        _hoveredConcept = concept;
+        _hoveredConceptLabel = concept.DisplayLabel;
+    }
+
+    private void ClearHoveredConcept()
+    {
+        _hoveredConcept = null;
+        _hoveredConceptLabel = string.Empty;
+    }
+
+    private async Task LoadProfileAsync()
     {
         var result = await IdentityService.GetProfileAsync();
         if (result.IsSuccess) 
         {
             _profile = result.Value;
         }
+        else
+        {
+            _profile = null;
+        }
+        StateHasChanged();
+    }
+
+    private async Task HandleStateInvalidatedAsync()
+    {
+        await InvokeAsync(async () =>
+        {
+            await LoadProfileAsync();
+        });
+    }
+
+    private async Task HandleProgressReceivedAsync(string pageId, DateTime timestamp)
+    {
+        await InvokeAsync(async () =>
+        {
+            IdentityService.ClearCache();
+            await LoadProfileAsync();
+        });
+    }
+
+    public void Dispose()
+    {
+        IdentityService.OnStateInvalidated -= HandleStateInvalidatedAsync;
+        SyncService.OnProgressReceived -= HandleProgressReceivedAsync;
     }
 }
+

src/NexusReader.UI.Shared/Pages/Dashboard.razor.css

@@ -294,9 +294,19 @@
 }
 
 .graph-node.satellite {
-    width: 20px;
-    height: 20px;
+    width: 16px;
+    height: 16px;
     transform: rotate(var(--angle)) translateY(var(--dist));
+    background: rgba(0, 255, 153, 0.4);
+    border: 1px solid var(--nexus-neon);
+    cursor: pointer;
+    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.graph-node.satellite:hover {
+    background: var(--nexus-neon);
+    box-shadow: 0 0 15px var(--nexus-neon);
+    transform: rotate(var(--angle)) translateY(var(--dist)) scale(1.3);
 }
 
 .active-node-label {
@@ -404,3 +414,117 @@
         grid-template-columns: 1fr;
     }
 }
+
+/* --- Quiz History Styling --- */
+.quiz-history-list {
+    display: flex;
+    flex-direction: column;
+    gap: 1rem;
+}
+
+.quiz-history-item {
+    background: rgba(255, 255, 255, 0.02);
+    border: 1px solid rgba(255, 255, 255, 0.05);
+    border-radius: 12px;
+    padding: 1rem;
+    transition: all 0.2s ease;
+}
+
+.quiz-history-item:hover {
+    background: rgba(255, 255, 255, 0.04);
+    border-color: rgba(255, 255, 255, 0.1);
+}
+
+.quiz-item-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    gap: 1rem;
+    margin-bottom: 0.5rem;
+}
+
+.quiz-topic {
+    font-size: 0.95rem;
+    font-weight: 500;
+    color: #ffffff;
+}
+
+.quiz-item-meta {
+    display: flex;
+    font-size: 0.75rem;
+    color: #666666;
+}
+
+.badge {
+    padding: 0.25rem 0.5rem;
+    border-radius: 6px;
+    font-size: 0.75rem;
+    font-weight: 600;
+}
+
+.badge-success {
+    background: rgba(0, 255, 153, 0.1);
+    color: var(--nexus-neon);
+    border: 1px solid rgba(0, 255, 153, 0.3);
+}
+
+.badge-warning {
+    background: rgba(255, 170, 0, 0.1);
+    color: #ffa800;
+    border: 1px solid rgba(255, 170, 0, 0.3);
+}
+
+.badge-danger {
+    background: rgba(255, 50, 50, 0.1);
+    color: #ff3232;
+    border: 1px solid rgba(255, 50, 50, 0.3);
+}
+
+.empty-quiz-state {
+    text-align: center;
+    padding: 2rem 1rem;
+}
+
+.empty-quiz-state .sub-text {
+    font-size: 0.8rem;
+    color: #666666;
+    margin-top: 0.5rem;
+}
+
+/* --- Concept Detail Toast for Dashboard --- */
+.concept-detail-toast {
+    margin-top: 1rem;
+    padding: 0.75rem 1rem;
+    background: rgba(255, 255, 255, 0.02);
+    border: 1px solid rgba(255, 255, 255, 0.05);
+    border-radius: 12px;
+    min-height: 80px;
+    display: flex;
+    flex-direction: column;
+    gap: 0.25rem;
+    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.concept-detail-toast.placeholder {
+    opacity: 0.5;
+}
+
+.concept-type {
+    font-size: 0.75rem;
+    font-weight: 700;
+    color: var(--nexus-neon);
+    text-transform: uppercase;
+    letter-spacing: 1px;
+}
+
+.concept-content {
+    font-size: 0.85rem;
+    line-height: 1.4;
+    color: #E0E0E0;
+    margin: 0;
+    display: -webkit-box;
+    -webkit-line-clamp: 2;
+    -webkit-box-orient: vertical;
+    overflow: hidden;
+}
+

src/NexusReader.UI.Shared/Services/ISyncService.cs

@@ -7,5 +7,6 @@ public interface ISyncService
     Task<Result> InitializeAsync();
     Task<Result> UpdateProgressAsync(string pageId, Guid ebookId, double progress, string? chapterTitle, int chapterIndex);
     event Func<string, DateTime, Task> OnProgressReceived;
+    event Func<string, double, Task>? OnIngestionProgressReceived;
     Task DisposeAsync();
 }

src/NexusReader.UI.Shared/Services/IdentityService.cs

@@ -249,6 +249,25 @@ public class IdentityService : IIdentityService
         }
     }
 
+    public void ClearCache()
+    {
+        _cachedProfile = null;
+        if (OnStateInvalidated != null)
+        {
+            _ = Task.Run(async () =>
+            {
+                try
+                {
+                    await OnStateInvalidated.Invoke();
+                }
+                catch
+                {
+                    // Ignore exceptions from event handlers
+                }
+            });
+        }
+    }
+
     private class LoginResponse
     {
         public string TokenType { get; set; } = string.Empty;

src/NexusReader.UI.Shared/Services/KnowledgeCoordinator.cs

@@ -17,6 +17,8 @@ public sealed partial class KnowledgeCoordinator : IDisposable
     private readonly IReaderInteractionService _interactionService;
     private readonly ILogger<KnowledgeCoordinator> _logger;
     
+    public string CurrentFullPageContent { get; private set; } = string.Empty;
+    
     /// <summary>
     /// Raised when the knowledge graph has been updated with new data.
     /// Subscribers must return a Task to enable proper async handling.
@@ -77,6 +79,7 @@ public sealed partial class KnowledgeCoordinator : IDisposable
     {
         if (string.IsNullOrWhiteSpace(fullContent)) return;
 
+        CurrentFullPageContent = fullContent;
         LogGeneratingGraph(tenantId);
         
         await _graphService.Clear();
@@ -94,11 +97,15 @@ public sealed partial class KnowledgeCoordinator : IDisposable
                     if (OnGraphUpdated != null)
                         await OnGraphUpdated.Invoke(packet.Graph);
                     await _platformService.VibrateSuccessAsync();
+                    return;
                 }
             }
+            
+            await _graphService.SetLoading(false);
         }
         catch (Exception ex)
         {
+            await _graphService.SetLoading(false);
             LogGraphError(ex, tenantId);
         }
     }
@@ -144,6 +151,7 @@ public sealed partial class KnowledgeCoordinator : IDisposable
 
     public async Task ClearAsync()
     {
+        CurrentFullPageContent = string.Empty;
         await _graphService.Clear();
         await _quizService.SetQuiz(null, null);
     }

src/NexusReader.UI.Shared/Services/SyncService.cs

@@ -16,6 +16,7 @@ public class SyncService : ISyncService, IAsyncDisposable
     private CancellationTokenSource? _debounceCts;
 
     public event Func<string, DateTime, Task>? OnProgressReceived;
+    public event Func<string, double, Task>? OnIngestionProgressReceived;
 
     public SyncService(
         HttpClient httpClient,
@@ -50,9 +51,20 @@ public class SyncService : ISyncService, IAsyncDisposable
         _hubConnection.On<string, DateTime>("ProgressUpdated", async (pageId, timestamp) =>
         {
             // Note: In the future we might want to receive ebookId and progress here too
+            if (pageId == _lastSentPageId)
+            {
+                _logger.LogDebug("[Sync] Ignoring self progress update for page {PageId}.", pageId);
+                return;
+            }
+            _lastSentPageId = pageId; // Prevent echoing back duplicate progress updates
             if (OnProgressReceived != null) await OnProgressReceived(pageId, timestamp);
         });
 
+        _hubConnection.On<string, double>("IngestionProgress", async (message, progress) =>
+        {
+            if (OnIngestionProgressReceived != null) await OnIngestionProgressReceived(message, progress);
+        });
+
         try
         {
             await _hubConnection.StartAsync();
@@ -71,6 +83,8 @@ public class SyncService : ISyncService, IAsyncDisposable
     {
         if (pageId == _lastSentPageId) return Result.Ok();
         
+        _lastSentPageId = pageId;
+        
         // Proper trailing-edge debounce
         _debounceCts?.Cancel();
         _debounceCts = new CancellationTokenSource();
@@ -86,8 +100,7 @@ public class SyncService : ISyncService, IAsyncDisposable
 
                 if (_hubConnection?.State == HubConnectionState.Connected)
                 {
-                    await _hubConnection.SendAsync("UpdateProgress", pageId, ebookId, progress, chapterTitle, token);
-                    _lastSentPageId = pageId;
+                    await _hubConnection.SendAsync("UpdateProgress", pageId, ebookId, progress, chapterTitle, chapterIndex);
                 }
             }
             catch (TaskCanceledException) { /* Ignored, user kept scrolling */ }

src/NexusReader.UI.Shared/wwwroot/js/knowledgeGraph.js

@@ -3,6 +3,110 @@ import * as d3 from 'https://esm.sh/d3@7';
 const getDisplayLabel = d => d.label.length > 20 ? d.label.substring(0, 17) + "..." : d.label;
 const getPillWidth = d => getDisplayLabel(d).length * 8 + 30;
 
+const getNodeType = d => {
+    if (d) {
+        if (d.type) {
+            const t = d.type.toLowerCase();
+            if (t === 'definition') return 'definition';
+            if (t === 'table') return 'table';
+            if (t === 'rule') return 'rule';
+            if (t === 'section') return 'section';
+        }
+        if (d.group) {
+            const g = d.group.toLowerCase();
+            if (g === 'definition') return 'definition';
+            if (g === 'table') return 'table';
+            if (g === 'rule') return 'rule';
+            if (g === 'section') return 'section';
+        }
+    }
+    return null;
+};
+
+const getNodeGroup = d => {
+    if (d && d.group) {
+        const g = d.group.toLowerCase();
+        if (g === 'bridge') return 'bridge';
+        if (g === 'current') return 'current';
+        if (g === 'concept') return 'concept';
+    }
+    return 'concept'; // fallback
+};
+
+const getCategoryStyle = d => {
+    const type = getNodeType(d);
+    const group = getNodeGroup(d);
+
+    // 1. Rule (red/coral)
+    if (type === 'rule') {
+        return {
+            color: '#ff4646',
+            fill: 'rgba(255, 70, 70, 0.1)',
+            opacity: 0.8,
+            glowKey: 'rule',
+            textColor: '#ff8b8b'
+        };
+    }
+    // 2. Definition (gold/amber)
+    if (type === 'definition') {
+        return {
+            color: '#ffb03a',
+            fill: 'rgba(255, 176, 58, 0.1)',
+            opacity: 0.8,
+            glowKey: 'definition',
+            textColor: '#ffd18c'
+        };
+    }
+    // 3. Table (purple/magenta)
+    if (type === 'table') {
+        return {
+            color: '#d946ef',
+            fill: 'rgba(217, 70, 239, 0.1)',
+            opacity: 0.8,
+            glowKey: 'table',
+            textColor: '#f5d0fe'
+        };
+    }
+    // 4. Section (blue/indigo)
+    if (type === 'section') {
+        return {
+            color: '#3b82f6',
+            fill: 'rgba(59, 130, 246, 0.1)',
+            opacity: 0.8,
+            glowKey: 'section',
+            textColor: '#93c5fd'
+        };
+    }
+    // 5. Bridge (cyan/comparison)
+    if (group === 'bridge') {
+        return {
+            color: '#06b6d4',
+            fill: 'rgba(6, 182, 212, 0.1)',
+            opacity: 0.7,
+            glowKey: 'bridge',
+            textColor: '#67e8f9'
+        };
+    }
+    // 6. Current (active/focus landmark - neon green)
+    if (group === 'current') {
+        return {
+            color: 'var(--nexus-neon)',
+            fill: 'rgba(0, 255, 153, 0.15)',
+            opacity: 0.9,
+            glowKey: 'current',
+            textColor: '#ffffff'
+        };
+    }
+    // 7. Concept / Default (subtle cool steel blue/teal)
+    return {
+        color: '#00d2c4',
+        fill: 'rgba(0, 210, 196, 0.05)',
+        opacity: 0.4,
+        glowKey: 'concept',
+        textColor: '#e0e0e0'
+    };
+};
+
 let simulation;
 let zoomBehavior;
 let svgElement;
@@ -24,8 +128,10 @@ export function mount(containerId, data, dotNetHelper) {
         .attr("height", "100%")
         .style("background", "radial-gradient(circle, #1a1a1a 0%, #121212 100%)");
 
-    // Radial gradient for Nebula effect
+    // Radial gradients for Nebula effects
     const defs = svgElement.append("defs");
+    
+    // Fallback radial gradient for legacy nebulaGlow
     const radialGradient = defs.append("radialGradient")
         .attr("id", "nebulaGlow")
         .attr("cx", "50%")
@@ -34,6 +140,26 @@ export function mount(containerId, data, dotNetHelper) {
     radialGradient.append("stop").attr("offset", "0%").attr("stop-color", "var(--nexus-neon)").attr("stop-opacity", 1);
     radialGradient.append("stop").attr("offset", "100%").attr("stop-color", "var(--nexus-neon)").attr("stop-opacity", 0);
 
+    const colors = {
+        'rule': '#ff4646',
+        'definition': '#ffb03a',
+        'table': '#d946ef',
+        'section': '#3b82f6',
+        'bridge': '#06b6d4',
+        'current': 'var(--nexus-neon)',
+        'concept': '#00d2c4'
+    };
+
+    Object.entries(colors).forEach(([key, color]) => {
+        const radGrad = defs.append("radialGradient")
+            .attr("id", `nebulaGlow-${key}`)
+            .attr("cx", "50%")
+            .attr("cy", "50%")
+            .attr("r", "50%");
+        radGrad.append("stop").attr("offset", "0%").attr("stop-color", color).attr("stop-opacity", 1);
+        radGrad.append("stop").attr("offset", "100%").attr("stop-color", color).attr("stop-opacity", 0);
+    });
+
     // Root Group for Zoom
     rootGroup = svgElement.append("g").attr("class", "zoom-containment");
 
@@ -135,21 +261,33 @@ export function updateData(data) {
         }
     });
 
+    // Sanitize links to filter out any references to non-existent nodes
+    const nodeIds = new Set(data.nodes.map(n => n.id));
+    const validLinks = (data.links || []).filter(l => {
+        const srcId = typeof l.source === 'object' ? l.source.id : l.source;
+        const tgtId = typeof l.target === 'object' ? l.target.id : l.target;
+        return nodeIds.has(srcId) && nodeIds.has(tgtId);
+    });
+
     // Update Links
     link = rootGroup.select(".links-layer")
         .selectAll("path")
-        .data(data.links, d => d.source + "-" + d.target + "-" + d.relationType)
+        .data(validLinks, d => {
+            const srcId = typeof d.source === 'object' ? d.source.id : d.source;
+            const tgtId = typeof d.target === 'object' ? d.target.id : d.target;
+            return srcId + "-" + tgtId + "-" + d.type;
+        })
         .join(
             enter => enter.append("path")
                 .attr("stroke", d => {
-                    if (d.relationType === 'Defines') return 'var(--nexus-accent)';
-                    if (d.relationType === 'Next') return 'rgba(255,255,255,0.2)';
-                    if (d.relationType === 'Contains') return 'var(--nexus-neon)';
+                    if (d.type === 'Defines' || d.type === 'maps_to') return 'var(--nexus-accent, #00ffaa)';
+                    if (d.type === 'Next' || d.type === 'relates_to') return 'rgba(255,255,255,0.2)';
+                    if (d.type === 'Contains' || d.type === 'contains') return 'var(--nexus-neon)';
                     return 'rgba(255,255,255,0.1)';
                 })
                 .attr("fill", "none")
-                .attr("stroke-width", d => d.relationType === 'Defines' ? 2 : 1)
-                .attr("stroke-dasharray", d => d.relationType === 'References' ? "5,5" : "0")
+                .attr("stroke-width", d => (d.type === 'Defines' || d.type === 'maps_to') ? 2 : 1)
+                .attr("stroke-dasharray", d => d.type === 'References' ? "5,5" : "0")
                 .style("opacity", 0)
                 .call(enter => enter.transition().duration(500).style("opacity", 1)),
             update => update,
@@ -174,13 +312,8 @@ export function updateData(data) {
 
                 g.append("circle")
                     .attr("r", 30)
-                    .attr("fill", d => {
-                        if (d.type === 'Definition') return 'var(--nexus-accent)';
-                        if (d.type === 'Table') return 'var(--nexus-neon)';
-                        if (d.type === 'Rule') return '#ff4444';
-                        return "url(#nebulaGlow)";
-                    })
-                    .attr("opacity", d => d.group === 'current' ? 0.6 : 0.2);
+                    .attr("fill", d => `url(#nebulaGlow-${getCategoryStyle(d).glowKey})`)
+                    .attr("opacity", d => getCategoryStyle(d).opacity);
 
                 g.append("rect")
                     .attr("class", "node-pill")
@@ -189,23 +322,20 @@ export function updateData(data) {
                     .attr("width", d => getPillWidth(d))
                     .attr("height", 30)
                     .attr("rx", 15)
-                    .attr("fill", "rgba(20, 20, 20, 0.9)")
-                    .attr("stroke", d => {
-                        if (d.type === 'Definition') return 'var(--nexus-accent)';
-                        if (d.type === 'Rule') return '#ff4444';
-                        return "rgba(255, 255, 255, 0.1)";
-                    })
-                    .attr("stroke-width", 1);
+                    .attr("fill", "rgba(20, 20, 20, 0.95)")
+                    .attr("stroke", d => getCategoryStyle(d).color)
+                    .attr("stroke-width", d => getNodeGroup(d) === 'current' ? 2 : 1.2);
 
                 g.append("text")
                     .text(d => getDisplayLabel(d))
                     .attr("text-anchor", "middle")
                     .attr("y", 5)
-                    .attr("fill", d => d.type === 'Definition' ? 'var(--nexus-accent)' : '#ccc')
-                    .attr("font-size", "0.8rem");
+                    .attr("fill", d => getCategoryStyle(d).textColor)
+                    .attr("font-size", "0.8rem")
+                    .attr("font-weight", d => getNodeGroup(d) === 'current' ? '600' : 'normal');
 
                 g.append("title")
-                    .text(d => d.label);
+                    .text(d => d.description ? `${d.label}\n\n${d.description}` : d.label);
                 
                 g.transition().duration(500).style("opacity", 1);
                 
@@ -216,7 +346,7 @@ export function updateData(data) {
         );
 
     simulation.nodes(data.nodes);
-    simulation.force("link").links(data.links);
+    simulation.force("link").links(validLinks);
     simulation.alpha(0.5).restart();
 
     // Trigger zoom to fit after a short delay to allow simulation to settle
@@ -398,6 +528,15 @@ export function clear() {
             }
             simulation.nodes([]);
         }
+
+        // Reset selections
+        link = null;
+        node = null;
+
+        // Reset D3 zoom transform to clean identity state
+        if (svgElement && zoomBehavior) {
+            svgElement.call(zoomBehavior.transform, d3.zoomIdentity);
+        }
     } catch (e) {
         console.warn("Failed to clear force simulation safely:", e);
     }

src/NexusReader.Web.Client/Program.cs

@@ -51,6 +51,7 @@ builder.Services.AddSingleton<IEmbeddingGenerator<string, Embedding<float>>>(new
 builder.Services.AddSingleton<IBookStorageService>(new ThrowingBookStorageService());
 builder.Services.AddSingleton<IEbookRepository>(new ThrowingEbookRepository());
 builder.Services.AddSingleton<ISyncBroadcaster>(new ThrowingSyncBroadcaster());
+builder.Services.AddSingleton<IEpubExtractor>(new ThrowingEpubExtractor());
 
 builder.Services.AddApplication();
 builder.Services.AddScoped<IEpubReader, WasmEpubReader>();
@@ -99,3 +100,9 @@ public class ThrowingSyncBroadcaster : ISyncBroadcaster
     public Task BroadcastIngestionProgressAsync(string userId, string message, double progress, CancellationToken cancellationToken = default)
         => throw new NotSupportedException("Real-time broadcasting can only be performed by the server.");
 }
+
+public class ThrowingEpubExtractor : IEpubExtractor
+{
+    public Task<FluentResults.Result<List<string>>> ExtractChaptersTextAsync(string relativePath, CancellationToken cancellationToken = default)
+        => throw new NotSupportedException("EPUB text extraction is not supported in the WASM client.");
+}

src/NexusReader.Web/Program.cs

@@ -106,7 +106,8 @@ builder.Services.AddAuthentication(options =>
 
 builder.Services.AddIdentityApiEndpoints<NexusUser>()
     .AddRoles<IdentityRole>()
-    .AddEntityFrameworkStores<AppDbContext>();
+    .AddEntityFrameworkStores<AppDbContext>()
+    .AddClaimsPrincipalFactory<NexusReader.Web.Services.CustomUserClaimsPrincipalFactory>();
 
 builder.Services.ConfigureApplicationCookie(options =>
 {
@@ -194,6 +195,7 @@ using (var scope = app.Services.CreateScope())
 
             await dbContext.Database.MigrateAsync();
             await DbInitializer.SeedAsync(services);
+            await TriggerBackgroundProcessingForUnindexedBooksAsync(services);
 
             if (logger.IsEnabled(LogLevel.Information))
             {
@@ -337,13 +339,16 @@ app.MapPost("/api/library/ingest", async ([FromBody] IngestEbookRequest request,
         ? Convert.FromBase64String(request.CoverImageBase64) 
         : null;
 
+    var tenantId = user.FindFirst("TenantId")?.Value ?? "global";
+
     var command = new IngestEbookCommand(
         request.Title,
         request.AuthorName,
         coverData,
         epubData,
         request.Description,
-        userId
+        userId,
+        tenantId
     );
 
     var result = await mediator.Send(command);
@@ -563,6 +568,50 @@ app.MapRazorComponents<App>()
 
 app.Run();
 
+async Task TriggerBackgroundProcessingForUnindexedBooksAsync(IServiceProvider services)
+{
+    var logger = services.GetRequiredService<ILogger<Program>>();
+    try
+    {
+        var dbContextFactory = services.GetRequiredService<IDbContextFactory<NexusReader.Data.Persistence.AppDbContext>>();
+        using var dbContext = await dbContextFactory.CreateDbContextAsync();
+        
+        var unindexedEbooks = await dbContext.Ebooks
+            .Where(e => !e.IsReadyForReading)
+            .ToListAsync();
+            
+        if (unindexedEbooks.Any())
+        {
+            logger.LogInformation("[Startup] Found {Count} un-indexed ebooks. Triggering background processing...", unindexedEbooks.Count);
+            
+            foreach (var ebook in unindexedEbooks)
+            {
+                logger.LogInformation("[Startup] Queuing background processing for ebook: '{Title}' ({Id})", ebook.Title, ebook.Id);
+                
+                _ = Task.Run(async () =>
+                {
+                    try
+                    {
+                        using var scope = services.CreateScope();
+                        var scopedMediator = scope.ServiceProvider.GetRequiredService<IMediator>();
+                        await scopedMediator.Send(new ProcessEbookCommand(ebook.Id, ebook.UserId, ebook.TenantId));
+                    }
+                    catch (Exception ex)
+                    {
+                        using var scope = services.CreateScope();
+                        var scopedLogger = scope.ServiceProvider.GetRequiredService<ILogger<Program>>();
+                        scopedLogger.LogError(ex, "Failed to run background processing for ebook {EbookId} on startup", ebook.Id);
+                    }
+                });
+            }
+        }
+    }
+    catch (Exception ex)
+    {
+        logger.LogError(ex, "Error checking or triggering background processing for unindexed books on startup.");
+    }
+}
+
 public record KnowledgeRequest(string Text, Guid? EbookId = null);
 public record GroundednessRequest(string Answer, string Context);
 public record SemanticSearchRequest(string QueryText, int Limit = 5);

src/NexusReader.Web/Services/CustomUserClaimsPrincipalFactory.cs

@@ -0,0 +1,28 @@
+using System.Security.Claims;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.Extensions.Options;
+using NexusReader.Domain.Entities;
+
+namespace NexusReader.Web.Services;
+
+public class CustomUserClaimsPrincipalFactory : UserClaimsPrincipalFactory<NexusUser, IdentityRole>
+{
+    public CustomUserClaimsPrincipalFactory(
+        UserManager<NexusUser> userManager,
+        RoleManager<IdentityRole> roleManager,
+        IOptions<IdentityOptions> optionsAccessor)
+        : base(userManager, roleManager, optionsAccessor)
+    {
+    }
+
+    protected override async Task<ClaimsIdentity> GenerateClaimsAsync(NexusUser user)
+    {
+        var identity = await base.GenerateClaimsAsync(user);
+        if (!string.IsNullOrEmpty(user.TenantId))
+        {
+            identity.AddClaim(new Claim("TenantId", user.TenantId));
+        }
+        return identity;
+    }
+}

src/NexusReader.Web/Services/ServerIdentityService.cs

@@ -118,4 +118,22 @@ public class ServerIdentityService : IIdentityService
 
         return Result.Ok(result.Value);
     }
+
+    public void ClearCache()
+    {
+        if (OnStateInvalidated != null)
+        {
+            _ = Task.Run(async () =>
+            {
+                try
+                {
+                    await OnStateInvalidated.Invoke();
+                }
+                catch
+                {
+                    // Ignore
+                }
+            });
+        }
+    }
 }

tests/NexusReader.Application.Tests/Commands/SubmitQuizResultCommandHandlerTests.cs

@@ -0,0 +1,107 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using FluentAssertions;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Moq;
+using NexusReader.Application.Commands.Quiz;
+using NexusReader.Data.Persistence;
+using NexusReader.Domain.Entities;
+using Xunit;
+
+namespace NexusReader.Application.Tests.Commands;
+
+public class SubmitQuizResultCommandHandlerTests : IDisposable
+{
+    private readonly SqliteConnection _connection;
+    private readonly DbContextOptions<AppDbContext> _contextOptions;
+    private readonly Mock<IDbContextFactory<AppDbContext>> _dbContextFactoryMock;
+
+    public SubmitQuizResultCommandHandlerTests()
+    {
+        _connection = new SqliteConnection("DataSource=:memory:");
+        _connection.Open();
+
+        _contextOptions = new DbContextOptionsBuilder<AppDbContext>()
+            .UseSqlite(_connection)
+            .Options;
+
+        using var context = new AppDbContext(_contextOptions);
+        context.Database.EnsureCreated();
+
+        _dbContextFactoryMock = new Mock<IDbContextFactory<AppDbContext>>();
+        _dbContextFactoryMock.Setup(f => f.CreateDbContextAsync(It.IsAny<CancellationToken>()))
+            .ReturnsAsync(() => new AppDbContext(_contextOptions));
+    }
+
+    [Fact]
+    public async Task Handle_WithValidRequest_PersistsQuizResultToDatabase()
+    {
+        // Arrange
+        using (var context = new AppDbContext(_contextOptions))
+        {
+            var user = new NexusUser
+            {
+                Id = "user-abc",
+                UserName = "testuser",
+                Email = "test@example.com",
+                TenantId = "tenant-xyz",
+                SubscriptionPlanId = 1
+            };
+            context.Users.Add(user);
+            await context.SaveChangesAsync();
+        }
+
+        var command = new SubmitQuizResultCommand(
+            UserId: "user-abc",
+            Topic: "Sprawdzian: .NET 10",
+            Score: 4,
+            TotalQuestions: 5
+        );
+
+        var handler = new SubmitQuizResultCommandHandler(_dbContextFactoryMock.Object);
+
+        // Act
+        var result = await handler.Handle(command, CancellationToken.None);
+
+        // Assert
+        result.IsSuccess.Should().BeTrue();
+
+        using (var context = new AppDbContext(_contextOptions))
+        {
+            var quizResult = await context.QuizResults.FirstOrDefaultAsync(q => q.UserId == "user-abc");
+            quizResult.Should().NotBeNull();
+            quizResult!.Topic.Should().Be("Sprawdzian: .NET 10");
+            quizResult.Score.Should().Be(4);
+            quizResult.TotalQuestions.Should().Be(5);
+            quizResult.TenantId.Should().Be("tenant-xyz");
+        }
+    }
+
+    [Fact]
+    public async Task Handle_WithNonExistentUser_ReturnsFailureResult()
+    {
+        // Arrange
+        var command = new SubmitQuizResultCommand(
+            UserId: "non-existent",
+            Topic: "Sprawdzian: .NET 10",
+            Score: 4,
+            TotalQuestions: 5
+        );
+
+        var handler = new SubmitQuizResultCommandHandler(_dbContextFactoryMock.Object);
+
+        // Act
+        var result = await handler.Handle(command, CancellationToken.None);
+
+        // Assert
+        result.IsFailed.Should().BeTrue();
+        result.Errors.Should().ContainSingle(e => e.Message == "User not found.");
+    }
+
+    public void Dispose()
+    {
+        _connection.Dispose();
+    }
+}

tests/NexusReader.Application.Tests/Queries/CheckDatabaseTest.cs

@@ -0,0 +1,58 @@
+using System;
+using System.IO;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using NexusReader.Data.Persistence;
+using Xunit;
+
+namespace NexusReader.Application.Tests.Queries;
+
+public class CheckDatabaseTest
+{
+    [Fact]
+    public async Task PrintDatabaseStats()
+    {
+        var configJson = await File.ReadAllTextAsync("../../../../../src/NexusReader.Web/appsettings.json");
+        var doc = JsonDocument.Parse(configJson);
+        var pgConn = doc.RootElement.GetProperty("ConnectionStrings").GetProperty("PostgresConnection").GetString();
+        
+        Console.WriteLine($"Postgres Connection: {pgConn}");
+        
+        var optionsBuilder = new DbContextOptionsBuilder<AppDbContext>();
+        optionsBuilder.UseNpgsql(pgConn);
+        
+        using var context = new AppDbContext(optionsBuilder.Options);
+        
+        var usersCount = await context.Users.CountAsync();
+        var ebooksCount = await context.Ebooks.CountAsync();
+        var unitsCount = await context.KnowledgeUnits.CountAsync();
+        var cacheCount = await context.SemanticKnowledgeCache.CountAsync();
+        
+        Console.WriteLine($"=== DATABASE STATS ===");
+        Console.WriteLine($"Users: {usersCount}");
+        Console.WriteLine($"Ebooks: {ebooksCount}");
+        Console.WriteLine($"KnowledgeUnits: {unitsCount}");
+        Console.WriteLine($"SemanticKnowledgeCache: {cacheCount}");
+        
+        var users = await context.Users.ToListAsync();
+        foreach (var u in users)
+        {
+            Console.WriteLine($"User: {u.Email}, TenantId: '{u.TenantId}'");
+        }
+        
+        var ebooks = await context.Ebooks.ToListAsync();
+        foreach (var eb in ebooks)
+        {
+            Console.WriteLine($"Ebook Id: {eb.Id}, Title: '{eb.Title}', FilePath: '{eb.FilePath}', Ready: {eb.IsReadyForReading}");
+        }
+        
+        var cache = await context.SemanticKnowledgeCache.ToListAsync();
+        foreach (var c in cache)
+        {
+            Console.WriteLine($"Cache Hash: {c.ContentHash}, TenantId: '{c.TenantId}', PromptVersion: {c.PromptVersion}, JsonData Preview: {c.JsonData.Substring(0, Math.Min(c.JsonData.Length, 150))}");
+        }
+        
+        Assert.True(true);
+    }
+}