feat(ui/graph): Knowledge Graph Refinement and Sidebar Hierarchy (#25)

This PR addresses several UI/UX and architectural refinements for the Knowledge Graph and Intelligence Sidebar.

### Key Changes:
- **Knowledge Graph (#21, #22)**:
  - Implemented \"pill-shaped\" nodes with dynamic label truncation and SVG tooltips.
  - Added bound-constrained simulation to keep nodes within the viewport.
  - Integrated `ResizeObserver` for dynamic layout handling.
  - Implemented Zoom-to-Fit functionality.
  - Enforced unique concept IDs in AI prompts and hardened JS logic to prevent multi-selection bugs.
- **Intelligence Sidebar (#23)**:
  - Improved visual depth with a radial gradient background for the graph.
  - Increased sidebar divider contrast for better layering.
  - Transformed graph controls into a floating glassmorphism panel.
  - Relocated the \"Logout\" action to the toolbar bottom and rebranded it as \"Exit\".

Fixes #21
Fixes #22
Fixes #23

Reviewed-on: #25
Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Co-committed-by: Marek Jasiński <jasins.marek@gmail.com>

.agent/skills/nexus-architecture-standards/SKILL.md

@@ -29,9 +29,12 @@ This skill defines the architectural guardrails for the NexusReader project to e
 - Use `FluentResults` (`Result<T>`) for all Application services and handlers.
 - Avoid throwing exceptions for expected business failures; use `Result.Fail()`.
 
-### 4. MediatR Patterns
-- **Queries**: Read-only operations. Should return `Result<T>`. Use `AsNoTracking()` in EF Core.
 - **Commands**: State-changing operations. Should return `Result` or `Result<T>`.
++
++### 5. Async Operations (Zero Tolerance for `async void`)
++- All asynchronous operations MUST return `Task` or `ValueTask`.
++- Event handlers MUST use `Func<Task>` or async-compatible patterns.
++- UI components MUST await all service calls and use `InvokeAsync(StateHasChanged)` for state updates within async contexts.
 
 ## Audit Scripts
 - [ArchCheck.sh](scripts/arch_check.sh): A shell script to scan for illegal cross-layer imports.

.agent/skills/nexus-graph-d3/SKILL.md

@@ -8,4 +8,7 @@ description: D3.js standards for Knowledge Graph
 - **JS Interop:** Use ES6 modules and `IJSObjectReference`.
 - **Responsiveness:** SVG must use `viewBox` for fluid portrait scaling.
 - **Visuals:** Use CSS variables (`--nexus-neon`) for node styling.
+- **Transitions:** Enforce smooth 500ms transitions using the D3.js General Update Pattern (`.join()`).
+- **Animations:** Implement "Neon Flash" entry animations for newly discovered knowledge nodes.
+- **Contextual Highlight:** Support node/link dimming to emphasize the current reading context.
 - **Events:** JS emits events (like `nodeClicked`) caught by Blazor via `DotNetObjectReference`.

.agent/skills/nexus-ui-engine/SKILL.md

@@ -22,7 +22,7 @@ description: Design System & Component rules for Blazor
     - Light Mode: `--nexus-bg` (`#f8f9fa`), `--nexus-card` (`#ffffff`).
   - **Typography:**
     - UI Elements: `Inter` (Sans-Serif) for controls, menus, and labels.
-    - Reading Content: `Merriweather` (Serif) for books and articles to ensure high readability.
+    - Reading Content: `Merriweather` (Serif) with `line-height: 1.65` and `letter-spacing: -0.01em` for high readability.
   - **Effects:**
     - Subtle neon glows (`box-shadow: 0 0 15px rgba(0, 255, 153, 0.3)`).
     - Glassmorphism for overlays and modals.
@@ -30,6 +30,11 @@ description: Design System & Component rules for Blazor
 - **Adaptive Layouts:**
   - Support `.platform-mobile` and `.platform-desktop` context classes.
   - Handle safe-area insets (`--safe-area-inset-*`) for mobile devices.
+  - **Immersive Reader (Zen Mode):**
+    - Centered content flow: `max-width: 800px`, `margin: 0 auto`.
+    - Paper-white background: `#F9F9F9` for light mode reader canvas.
+    - Dedicated Scrollbars: Custom styled, thin scrollbars with `--nexus-neon` accents.
+    - Reachability: Large `padding-bottom` (e.g., `15rem`) to ensure comfortable reading of end-of-page content.
 
 - **Accessibility (A11y):**
   - Touch Targets: Min `44x44px` on mobile (enforced via CSS variables).

src/NexusReader.Application/Commands/Sync/UpdateReadingProgressCommand.cs

@@ -3,4 +3,4 @@ using MediatR;
 
 namespace NexusReader.Application.Commands.Sync;
 
-public record UpdateReadingProgressCommand(string PageId, string UserId) : IRequest<Result>;
+public record UpdateReadingProgressCommand(string PageId, string UserId, string? ExcludedConnectionId = null) : IRequest<Result>;

src/NexusReader.Application/DependencyInjection.cs

@@ -8,6 +8,7 @@ public static class DependencyInjection
     public static IServiceCollection AddApplication(this IServiceCollection services)
     {
         services.AddMapsterConfiguration();
+        services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(typeof(DependencyInjection).Assembly));
 
         return services;
     }

src/NexusReader.Infrastructure/Handlers/UpdateReadingProgressCommandHandler.cs

@@ -38,9 +38,18 @@ public class UpdateReadingProgressCommandHandler : IRequestHandler<UpdateReading
         await context.SaveChangesAsync(cancellationToken);
 
         // Broadcast to other devices
-        await _hubContext.Clients
-            .Group($"User_{request.UserId}")
-            .SendAsync("ProgressUpdated", request.PageId, now, cancellationToken);
+        var group = _hubContext.Clients.Group($"User_{request.UserId}");
+        
+        if (!string.IsNullOrEmpty(request.ExcludedConnectionId))
+        {
+            await _hubContext.Clients
+                .GroupExcept($"User_{request.UserId}", request.ExcludedConnectionId)
+                .SendAsync("ProgressUpdated", request.PageId, now, cancellationToken);
+        }
+        else
+        {
+            await group.SendAsync("ProgressUpdated", request.PageId, now, cancellationToken);
+        }
 
         return Result.Ok();
     }

src/NexusReader.Infrastructure/RealTime/SyncHub.cs

@@ -20,7 +20,7 @@ public class SyncHub : Hub
         var userId = Context.UserIdentifier;
         if (!string.IsNullOrEmpty(userId))
         {
-            await _mediator.Send(new UpdateReadingProgressCommand(pageId, userId));
+            await _mediator.Send(new UpdateReadingProgressCommand(pageId, userId, Context.ConnectionId));
         }
     }
 

src/NexusReader.Infrastructure/Services/EpubService.cs

@@ -46,34 +46,35 @@ public class EpubService : IEpubService
                 return Result.Fail($"EPUB file at '{fullPath}' is not accessible or does not exist.");
             }
 
-            EpubBook book;
-            try 
-            {
-                book = await EpubReader.ReadBookAsync(fullPath);
-            }
-            catch (Exception ex)
-            {
-                return Result.Fail(new Error($"Failed to parse EPUB file. It might be corrupted or in use. Path: {fullPath}").CausedBy(ex));
-            }
-            var blocks = new List<ContentBlock>();
-            int totalWordCount = 0;
-            int blockCounter = 0;
+            using var bookRef = await EpubReader.OpenBookAsync(fullPath);
+            var readingOrder = bookRef.GetReadingOrder();
 
-            if (book.ReadingOrder == null || !book.ReadingOrder.Any())
+            if (readingOrder == null || !readingOrder.Any())
             {
                 return Result.Fail("The EPUB has no readable content files in ReadingOrder.");
             }
 
             // Ensure index is within bounds
-            if (chapterIndex < 0 || chapterIndex >= book.ReadingOrder.Count)
+            if (chapterIndex < 0 || chapterIndex >= readingOrder.Count)
             {
                 chapterIndex = 0; // Default to first chapter
             }
 
-            var chapter = book.ReadingOrder[chapterIndex];
-            var chapterTitle = chapter.FilePath ?? $"Chapter {chapterIndex + 1}";
+            var chapterRef = readingOrder[chapterIndex];
+            
+            // Try to find a better title from navigation (TOC)
+            var navigation = bookRef.GetNavigation();
+            var chapterTitle = FindTitleInNavigation(navigation, chapterRef.FilePath) 
+                               ?? Path.GetFileNameWithoutExtension(chapterRef.FilePath) 
+                               ?? $"Chapter {chapterIndex + 1}";
 
-            var paragraphs = ExtractParagraphs(chapter.Content);
+            var chapterContent = await chapterRef.ReadContentAsTextAsync();
+
+            var blocks = new List<ContentBlock>();
+            int totalWordCount = 0;
+            int blockCounter = 0;
+
+            var paragraphs = ExtractParagraphs(chapterContent);
             foreach (var p in paragraphs)
             {
                 var sanitizedContent = SanitizeParagraph(p);
@@ -99,7 +100,7 @@ public class EpubService : IEpubService
                 blocks.Add(CreateAiTrigger($"trigger-{blockCounter++}"));
             }
 
-            return Result.Ok(new ReaderPageViewModel(blocks, chapterIndex, book.ReadingOrder.Count, chapterTitle));
+            return Result.Ok(new ReaderPageViewModel(blocks, chapterIndex, readingOrder.Count, chapterTitle));
         }
         catch (Exception ex)
         {
@@ -162,4 +163,25 @@ public class EpubService : IEpubService
             new List<string> { "Podsumuj", "Generuj Quiz", "Pomiń" }
         );
     }
+
+    private string? FindTitleInNavigation(IEnumerable<EpubNavigationItemRef> navigation, string? filePath)
+    {
+        if (string.IsNullOrEmpty(filePath)) return null;
+        
+        var fileName = Path.GetFileName(filePath);
+
+        foreach (var item in navigation)
+        {
+            // Match by full path or just filename as fallback
+            if (item.Link?.ContentFilePath == filePath || item.Link?.ContentFilePath == fileName)
+                return item.Title;
+                
+            if (item.NestedItems != null && item.NestedItems.Any())
+            {
+                var childTitle = FindTitleInNavigation(item.NestedItems, filePath);
+                if (childTitle != null) return childTitle;
+            }
+        }
+        return null;
+    }
 }

src/NexusReader.Infrastructure/Services/PromptRegistry.cs

@@ -4,6 +4,8 @@ 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). " +
+        "CRITICAL: Extract a MAXIMUM of 15 key concepts/plot points from the text. " +
         "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\" } ], " +
@@ -13,11 +15,15 @@ public static class PromptRegistry
 
     public const string GraphExtractionPrompt = 
         "You are an expert at information architecture. Extract key concepts and their relationships from the text to build a knowledge graph. " +
-        "CRITICAL: Each paragraph in the user text starts with [ID: some-id]. You MUST use these exact IDs as the 'id' for the nodes representing those blocks. " +
+        "CRITICAL: Restrict 'label' to a maximum of 3 words. " +
+        "CRITICAL: Extract a MAXIMUM of 15 key concepts/plot points and their relationships. " +
+        "CRITICAL: Each paragraph in the user text starts with [ID: some-id]. Use these IDs ONLY for nodes representing the blocks. " +
+        "CRITICAL: All other extracted 'concept' nodes MUST have unique, slug-style IDs based on their labels (e.g., 'dependency-injection'). " +
         "Include a 'current' node representing the block content itself if applicable. " +
         "CRITICAL: Limit the result to a MAXIMUM of 15 most relevant connections. " +
         "Return ONLY minified JSON. Schema: { \"graph\": { \"nodes\": [ { \"id\": \"string\", \"label\": \"string\", \"group\": \"concept|current\" } ], \"links\": [ { \"source\": \"string\", \"target\": \"string\", \"value\": 1 } ] } }";
 
+
     public const string SummaryAndQuizPrompt = 
         "You are an expert educator. Provide a concise summary of the text and generate a challenging quiz (3-5 questions). " +
         "Return ONLY minified JSON. Schema: { \"summary\": \"string\", \"quizzes\": [ { \"question\": \"string\", \"options\": [ \"string\" ], \"correct_index\": 0 } ] }";

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

@@ -40,6 +40,15 @@
         case "eye-off":
             <path d="M9.88 9.88a3 3 0 1 0 4.24 4.24" /><path d="M10.73 5.08A10.43 10.43 0 0 1 12 5c7 0 10 7 10 7a13.16 13.16 0 0 1-1.67 2.68" /><path d="M6.61 6.61A13.52 13.52 0 0 0 2 12s3 7 10 7a9.74 9.74 0 0 0 5.39-1.61" /><line x1="2" x2="22" y1="2" y2="22" />
             break;
+        case "arrow-left":
+            <path d="M19 12H5M12 19l-7-7 7-7" />
+            break;
+        case "arrow-right":
+            <path d="M5 12h14M12 5l7 7-7 7" />
+            break;
+        case "log-out":
+            <path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4M16 17l5-5-5-5M21 12H9" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
+            break;
         default:
             <!-- Fallback circle -->
             <circle cx="12" cy="12" r="10" />

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

@@ -42,6 +42,7 @@
     /// <summary>Fallback static dialogue shown when no live AI content is available.</summary>
     [Parameter] public string Dialogue { get; set; } = string.Empty;
     [Parameter] public List<string> Actions { get; set; } = new();
+    [Parameter] public string FullPageContent { get; set; } = string.Empty;
     [Parameter] public EventCallback<string> OnActionTriggered { get; set; }
 
     private string _displayedText = string.Empty;
@@ -76,8 +77,11 @@
 
         try
         {
-            _packet = await Coordinator.RequestSummaryAndQuizAsync(
-                $"[ID: {ContextBlockId}]\n{Dialogue}");
+            var contentToAnalyze = !string.IsNullOrWhiteSpace(FullPageContent) 
+                ? FullPageContent 
+                : $"[ID: {ContextBlockId}]\n{Dialogue}";
+
+            _packet = await Coordinator.RequestSummaryAndQuizAsync(contentToAnalyze);
 
             var summary = _packet?.Summary;
 
@@ -125,7 +129,7 @@
     {
         if (action.Contains("quiz", StringComparison.OrdinalIgnoreCase))
         {
-            QuizState.RequestQuiz(ContextBlockId);
+            await QuizState.RequestQuiz(ContextBlockId);
         }
 
         if (OnActionTriggered.HasDelegate)

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

@@ -2,6 +2,8 @@
 @using NexusReader.Application.Abstractions.Services
 @inject IFocusModeService FocusMode
 @inject IKnowledgeService KnowledgeService
+@inject IIdentityService IdentityService
+@inject NavigationManager NavigationManager
 
 <aside class="intelligence-toolbar">
     <div class="toolbar-top">
@@ -36,13 +38,16 @@
         <button class="toolbar-item" title="Global Settings">
             <NexusIcon Name="settings" Size="20" />
         </button>
+        <button class="toolbar-item logout-item" @onclick="HandleLogout" title="Exit">
+            <NexusIcon Name="log-out" Size="20" />
+        </button>
     </div>
 </aside>
 
 @code {
     protected override void OnInitialized()
     {
-        FocusMode.OnFocusModeChanged += StateHasChanged;
+        FocusMode.OnFocusModeChanged += HandleUpdate;
     }
 
     private async Task HandleClearCache()
@@ -56,8 +61,16 @@
         }
     }
 
+    private async Task HandleLogout()
+    {
+        await IdentityService.LogoutAsync();
+        NavigationManager.NavigateTo("/", true);
+    }
+
+    private Task HandleUpdate() => InvokeAsync(StateHasChanged);
+
     public void Dispose()
     {
-        FocusMode.OnFocusModeChanged -= StateHasChanged;
+        FocusMode.OnFocusModeChanged -= HandleUpdate;
     }
 }

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

@@ -1,8 +1,8 @@
 .intelligence-toolbar {
     width: 50px;
     height: 100%;
-    background: #080808;
-    border-right: 1px solid rgba(255, 255, 255, 0.03);
+    background: #0D0D0D;
+    border-right: 1px solid rgba(255, 255, 255, 0.08);
     display: flex;
     flex-direction: column;
     justify-content: space-between;
@@ -10,6 +10,7 @@
     align-items: center;
     z-index: 20;
     box-shadow: inset -2px 0 10px rgba(0,0,0,0.5);
+    backdrop-filter: blur(10px);
 }
 
 
@@ -22,7 +23,7 @@
 .toolbar-item {
     background: none;
     border: none;
-    color: #444;
+    color: #555;
     cursor: pointer;
     width: 34px;
     height: 34px;
@@ -37,11 +38,15 @@
 .toolbar-item:hover {
     color: var(--nexus-neon);
     background: rgba(0, 255, 153, 0.05);
+    box-shadow: 0 0 15px rgba(0, 255, 153, 0.15);
+    filter: drop-shadow(0 0 5px var(--nexus-neon));
 }
 
 .toolbar-item.active {
     color: var(--nexus-neon);
     background: rgba(0, 255, 153, 0.08);
+    box-shadow: 0 0 20px rgba(0, 255, 153, 0.25);
+    filter: drop-shadow(0 0 8px var(--nexus-neon));
 }
 
 .toolbar-item.active::after {
@@ -70,3 +75,22 @@
     color: #ff4d4d;
     background: rgba(255, 77, 77, 0.1);
 }
+
+.toolbar-item.logout-item {
+    margin-top: 1rem;
+    border-top: 1px solid rgba(255, 255, 255, 0.08);
+    padding-top: 1.5rem;
+    height: auto;
+    width: 100%;
+    display: flex;
+    justify-content: center;
+    border-radius: 0;
+    color: #444;
+}
+
+.toolbar-item.logout-item:hover {
+    color: #ff4d4d;
+    background: none;
+    filter: drop-shadow(0 0 8px rgba(255, 77, 77, 0.4));
+}
+

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

@@ -55,12 +55,14 @@
 
     protected override void OnInitialized()
     {
-        QuizService.OnQuizUpdated += () => InvokeAsync(StateHasChanged);
+        QuizService.OnQuizUpdated += HandleUpdate;
     }
 
+    private Task HandleUpdate() => InvokeAsync(StateHasChanged);
+
     public void Dispose()
     {
-        QuizService.OnQuizUpdated -= StateHasChanged;
+        QuizService.OnQuizUpdated -= HandleUpdate;
     }
 
     private async Task SelectOptionAsync(QuizQuestionDto question, int index)

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

@@ -29,7 +29,7 @@
                     </div>
                     <div class="ai-actions">
                         <button class="action-btn neon-border" @onclick="GenerateFullQuiz">Generuj Quiz dla całej strony</button>
-                        <button class="action-btn ghost" @onclick="Close">Zamknij</button>
+                        <button class="action-btn ghost" @onclick="CloseAsync">Zamknij</button>
                     </div>
                 }
                 else
@@ -39,7 +39,7 @@
                     </div>
                     <div class="ai-actions">
                         <button class="action-btn neon-border" @onclick="RequestSummary">Podsumuj zaznaczenie</button>
-                        <button class="action-btn ghost" @onclick="Close">Pomiń</button>
+                        <button class="action-btn ghost" @onclick="CloseAsync">Pomiń</button>
                     </div>
                 }
             </div>
@@ -76,7 +76,11 @@
     private async Task RequestSummary()
     {
         IsLoading = true;
-        Packet = await Coordinator.RequestSummaryAndQuizAsync(SelectedText);
+        var contextPrompt = !string.IsNullOrWhiteSpace(FullPageContent) 
+            ? $"ANALYSIS CONTEXT (Full Page Content):\n{FullPageContent}\n\nUSER SELECTION TO SUMMARIZE:\n" 
+            : "";
+        
+        Packet = await Coordinator.RequestSummaryAndQuizAsync($"{contextPrompt}{SelectedText}");
         IsLoading = false;
     }
 
@@ -85,12 +89,12 @@
         IsLoading = true;
         await Coordinator.RequestSummaryAndQuizAsync(FullPageContent);
         IsLoading = false;
-        Close();
+        await CloseAsync();
     }
 
-    private void Close()
+    private async Task CloseAsync()
     {
         Packet = null;
-        InteractionService.NotifyTextSelected(string.Empty, string.Empty, null!);
+        await InteractionService.NotifyTextSelected(string.Empty, string.Empty, null!);
     }
 }

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

@@ -46,7 +46,7 @@
         GraphService.OnLoadingChanged += HandleLoadingChange;
     }
 
-    private async void HandleGraphUpdate()
+    private async Task HandleGraphUpdate()
     {
         if (_module == null) return;
         
@@ -62,13 +62,13 @@
         await InvokeAsync(StateHasChanged);
     }
 
-    private async void HandleActiveNodeChange(string nodeId)
+    private async Task HandleActiveNodeChange(string nodeId)
     {
         if (_module == null) return;
         await _module.InvokeVoidAsync("setActiveNode", nodeId);
     }
 
-    private async void HandleLoadingChange(bool isLoading)
+    private async Task HandleLoadingChange(bool isLoading)
     {
         await InvokeAsync(StateHasChanged);
     }
@@ -81,7 +81,7 @@
             
             if (GraphService.CurrentGraphData != null)
             {
-                HandleGraphUpdate();
+                await HandleGraphUpdate();
             }
         }
     }
@@ -100,7 +100,7 @@
     [JSInvokable]
     public async Task OnNodeClicked(string nodeId)
     {
-        InteractionService.NotifyNodeSelected(nodeId);
+        await InteractionService.NotifyNodeSelected(nodeId);
         
         if (OnNodeSelected.HasDelegate)
         {
@@ -109,7 +109,7 @@
     }
 
 
-    private async void HandleFocusSimulation()
+    private async Task HandleFocusSimulation()
     {
         if (_module == null) return;
         try

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

@@ -12,28 +12,33 @@
 
 .graph-controls {
     position: absolute;
-    bottom: 1rem;
+    bottom: 1.5rem;
     right: 1.5rem;
     display: flex;
-    flex-direction: column;
-    gap: 0.5rem;
+    flex-direction: row;
+    gap: 0.25rem;
+    background: rgba(20, 20, 20, 0.4);
+    backdrop-filter: blur(12px);
+    padding: 0.35rem;
+    border-radius: 8px;
+    border: 1px solid rgba(255, 255, 255, 0.08);
+    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
     z-index: 10;
 }
 
 .zoom-btn {
-    width: 28px;
-    height: 28px;
-    background: rgba(18, 18, 18, 0.8);
-    backdrop-filter: blur(4px);
-    border: 1px solid rgba(255, 255, 255, 0.1);
-    border-radius: 4px;
-    color: #888;
-    font-size: 1rem;
+    width: 32px;
+    height: 32px;
+    background: rgba(255, 255, 255, 0.03);
+    border: 1px solid rgba(255, 255, 255, 0.05);
+    border-radius: 6px;
+    color: #aaa;
+    font-size: 1.1rem;
     cursor: pointer;
     display: flex;
     align-items: center;
     justify-content: center;
-    transition: all 0.2s ease;
+    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
 }
 
 .zoom-btn:hover {
@@ -98,3 +103,13 @@
     filter: drop-shadow(0 0 12px var(--nexus-neon));
     transition: all 0.3s ease;
 }
+
+::deep @keyframes neon-flash {
+    0% { filter: brightness(1) drop-shadow(0 0 0px var(--nexus-neon)); }
+    50% { filter: brightness(3) drop-shadow(0 0 30px var(--nexus-neon)); }
+    100% { filter: brightness(1) drop-shadow(0 0 0px var(--nexus-neon)); }
+}
+
+::deep .neon-flash-node {
+    animation: neon-flash 0.8s ease-out;
+}

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

@@ -52,15 +52,16 @@
     private bool _isJsInitialized;
     private ElementReference _containerRef;
 
-    protected override void OnInitialized()
+    protected override async Task OnInitializedAsync()
     {
-        Coordinator.Clear();
-        ThemeService.OnThemeChanged += StateHasChanged;
+        await Coordinator.ClearAsync();
+        ThemeService.OnThemeChanged += HandleUpdate;
         NavigationService.OnNavigationChanged += OnNavigationChanged;
         
         InteractionService.OnScrollToBlockRequested += HandleScrollRequested;
         InteractionService.OnHighlightBlockRequested += HandleHighlightRequested;
         InteractionService.OnTextSelected += HandleTextSelected;
+        SyncService.OnProgressReceived += HandleSyncProgressReceived;
     }
 
     protected override async Task OnParametersSetAsync()
@@ -113,60 +114,56 @@
     }
 
     [JSInvokable]
-    public void HandleBlockReached(string blockId, string content)
+    public async Task HandleBlockReached(string blockId, string content)
     {
-        Coordinator.OnBlockReached(blockId, content);
+        await Coordinator.OnBlockReachedAsync(blockId, content);
         
         // Debounce sync update (simple version: every 5 seconds or on a timer)
-        _ = SyncService.UpdateProgressAsync(blockId);
+        await SyncService.UpdateProgressAsync(blockId);
     }
 
-    private void HandleSyncProgressReceived(string blockId, DateTime timestamp)
+    private async Task HandleSyncProgressReceived(string blockId, DateTime timestamp)
     {
         // For now, let's just scroll to the node if it's in the current view, 
         // or just log it. Usually, we should prompt the user.
         Console.WriteLine($"[Sync] Received progress from another device: {blockId} at {timestamp}");
         
-        // Simple auto-scroll if it's newer than what we have (we don't track our own timestamp yet, 
-        // but we can assume incoming syncs are from other active devices)
-        _ = InvokeAsync(async () => {
-             await ScrollToNodeAsync(blockId);
-             StateHasChanged();
-        });
+        await ScrollToNodeAsync(blockId);
+        await InvokeAsync(StateHasChanged);
     }
 
     [JSInvokable]
-    public void HandleTextSelected(string text, string blockId, SelectionCoordinates coords)
+    public async Task HandleTextSelected(string text, string blockId, SelectionCoordinates coords)
     {
         Console.WriteLine($"[ReaderCanvas] Text selected: {text} at {coords.Top},{coords.Left}");
         _selectedText = text;
         _selectedBlockId = blockId;
         _selectionCoords = coords;
-        StateHasChanged();
+        await InvokeAsync(StateHasChanged);
     }
 
     [JSInvokable]
-    public void HandleSelectionCleared()
+    public async Task HandleSelectionCleared()
     {
         _selectedText = string.Empty;
         _selectionCoords = null;
-        StateHasChanged();
+        await InvokeAsync(StateHasChanged);
     }
 
-    private void HandleScrollRequested(string blockId)
+    private async Task HandleScrollRequested(string blockId)
     {
-        _ = ScrollToNodeAsync(blockId);
+        await ScrollToNodeAsync(blockId);
     }
 
-    private async void HandleHighlightRequested(string blockId)
+    private async Task HandleHighlightRequested(string blockId)
     {
         _highlightedBlockId = blockId;
-        StateHasChanged();
+        await InvokeAsync(StateHasChanged);
         await Task.Delay(3000); // Highlight for 3 seconds
         if (_highlightedBlockId == blockId)
         {
             _highlightedBlockId = null;
-            StateHasChanged();
+            await InvokeAsync(StateHasChanged);
         }
     }
 
@@ -212,9 +209,11 @@
         catch { }
     }
 
+    private Task HandleUpdate() => InvokeAsync(StateHasChanged);
+
     public void Dispose()
     {
-        ThemeService.OnThemeChanged -= StateHasChanged;
+        ThemeService.OnThemeChanged -= HandleUpdate;
         NavigationService.OnNavigationChanged -= OnNavigationChanged;
         
         InteractionService.OnScrollToBlockRequested -= HandleScrollRequested;

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

@@ -1,16 +1,47 @@
 .reader-canvas {
-    max-width: 800px;
-    margin: 0 auto;
-    padding: 2rem 1rem;
+    width: 100%;
+    height: 100%;
+    overflow-y: auto;
+    overflow-x: hidden;
+    padding: 2rem 0;
     transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
     position: relative;
+    
+    /* Dedicated Scrollbar Styling */
+    scrollbar-width: thin;
+    scrollbar-color: rgba(0, 255, 153, 0.2) transparent;
+}
+
+.reader-canvas::-webkit-scrollbar {
+    width: 6px;
+}
+
+.reader-canvas::-webkit-scrollbar-track {
+    background: transparent;
+}
+
+.reader-canvas::-webkit-scrollbar-thumb {
+    background-color: rgba(0, 255, 153, 0.2);
+    border-radius: 20px;
+    border: 3px solid transparent;
+}
+
+.reader-canvas:hover::-webkit-scrollbar-thumb {
+    background-color: rgba(0, 255, 153, 0.5);
+}
+
+.reader-canvas.theme-light {
+    background-color: #F9F9F9; /* Paper-white requirement */
 }
 
 .reader-flow-container {
+    max-width: 800px;
+    margin: 0 auto;
     display: flex;
     flex-direction: column;
     gap: 1.5rem;
     position: relative;
+    padding: 0 1.5rem 15rem 1.5rem; /* Large padding-bottom for reachability */
 }
 
 .block-wrapper {
@@ -20,6 +51,68 @@
     border: 1px solid transparent;
 }
 
+/* Typographic refinement for TextSegmentBlock */
+::deep .nexus-ebook {
+    font-family: 'Merriweather', serif !important;
+    line-height: 1.65 !important;
+    letter-spacing: -0.01em !important;
+    font-size: 1.15rem;
+    font-weight: 300;
+}
+
+.theme-light ::deep .nexus-ebook {
+    color: #1a1a1a;
+}
+
+/* Technical Code Block Container */
+::deep .nexus-ebook pre {
+    background-color: #2d2d2d; /* Dark theme for code for better contrast */
+    color: #e0e0e0;
+    padding: 1.25rem;
+    border-radius: 8px;
+    margin: 2rem 0;
+    overflow-x: auto;
+    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
+    border-left: 4px solid var(--nexus-neon); /* Nexus neon accent */
+    
+    /* Dedicated Scrollbar for Code */
+    scrollbar-width: thin;
+    scrollbar-color: rgba(0, 255, 153, 0.3) transparent;
+}
+
+::deep .nexus-ebook pre::-webkit-scrollbar {
+    height: 4px;
+}
+
+::deep .nexus-ebook pre::-webkit-scrollbar-thumb {
+    background: rgba(0, 255, 153, 0.3);
+    border-radius: 10px;
+}
+
+/* Monospace Typography Contrast */
+::deep .nexus-ebook code {
+    font-family: 'JetBrains Mono', 'Cascadia Code', 'Consolas', monospace !important;
+    font-variant-ligatures: contextual;
+    line-height: 1.5;
+    tab-size: 4;
+    font-size: 0.9rem;
+}
+
+/* Inline Code Highlight */
+::deep .nexus-ebook p code {
+    background-color: rgba(0, 0, 0, 0.05);
+    color: #d63384; /* Classic differentiator for inline code */
+    padding: 0.2rem 0.4rem;
+    border-radius: 4px;
+    font-size: 0.9em;
+    border: none;
+}
+
+.theme-dark ::deep .nexus-ebook p code {
+    background-color: rgba(255, 255, 255, 0.1);
+    color: #ff79c6;
+}
+
 .block-wrapper.highlighted {
     background: rgba(0, 243, 255, 0.08);
     box-shadow: 0 0 20px rgba(0, 243, 255, 0.15);

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

@@ -36,10 +36,9 @@
         NavigationService.OnNavigationChanged += HandleNavigationChanged;
     }
 
-    private Task HandleNavigationChanged()
+    private async Task HandleNavigationChanged()
     {
-        StateHasChanged();
-        return Task.CompletedTask;
+        await InvokeAsync(StateHasChanged);
     }
 
     private int CalculateProgress()

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

@@ -18,9 +18,11 @@
 }
 
 .navigation-controls {
-    display: flex;
+    display: grid;
+    grid-template-columns: 32px 1fr 32px;
     align-items: center;
-    gap: 1rem;
+    gap: 0.75rem;
+    width: 260px;
     flex-shrink: 0;
 }
 
@@ -51,18 +53,23 @@
 
 .chapter-info {
     display: flex;
+    flex-direction: column;
     align-items: center;
-    gap: 0.5rem;
-    font-size: 0.85rem;
+    justify-content: center;
+    min-width: 0;
+    overflow: hidden;
     color: #333;
-    white-space: nowrap;
 }
 
 .chapter-title {
     font-weight: 600;
-    max-width: 180px;
+    font-size: 0.75rem;
+    max-width: 100%;
     overflow: hidden;
     text-overflow: ellipsis;
+    white-space: nowrap;
+    text-align: center;
+    line-height: 1.2;
 }
 
 .chapter-count {

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

@@ -35,10 +35,7 @@
                             <span>Asystent AI</span>
                         </div>
 
-                        <div class="user-profile">
-                            <span class="user-email">@context.User.Identity?.Name</span>
-                            <button class="logout-btn" @onclick="HandleLogout">Logout</button>
-                        </div>
+
 
                         <button class="close-btn">×</button>
                     </div>
@@ -77,8 +74,8 @@
 
     protected override void OnInitialized()
     {
-        FocusMode.OnFocusModeChanged += StateHasChanged;
-        QuizService.OnQuizUpdated += StateHasChanged;
+        FocusMode.OnFocusModeChanged += HandleUpdate;
+        QuizService.OnQuizUpdated += HandleUpdate;
 
         var context = PlatformService.GetDeviceContext();
         if (context.IsSuccess)
@@ -93,11 +90,7 @@
         }
     }
 
-    private async Task HandleLogout()
-    {
-        await IdentityService.LogoutAsync();
-        NavigationManager.NavigateTo("/", true);
-    }
+
 
     protected override async Task OnAfterRenderAsync(bool firstRender)
     {
@@ -115,9 +108,11 @@
         }
     }
 
+    private Task HandleUpdate() => InvokeAsync(StateHasChanged);
+
     public void Dispose()
     {
-        FocusMode.OnFocusModeChanged -= StateHasChanged;
-        QuizService.OnQuizUpdated -= StateHasChanged;
+        FocusMode.OnFocusModeChanged -= HandleUpdate;
+        QuizService.OnQuizUpdated -= HandleUpdate;
     }
 }

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

@@ -20,9 +20,10 @@
 
 main {
     flex: 1;
-    overflow-y: auto;
-    overflow-x: hidden;
+    overflow: hidden;
     position: relative;
+    display: flex;
+    flex-direction: column;
 }
 
 .intelligence-sidebar {
@@ -32,7 +33,7 @@ main {
     height: 100%;
     background: #0d0d0d;
     box-shadow: -10px 0 30px rgba(0, 0, 0, 0.3);
-    border-left: 1px solid rgba(255, 255, 255, 0.05);
+    border-left: 1px solid rgba(255, 255, 255, 0.1);
     overflow: hidden;
     z-index: 10;
 }

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

@@ -22,8 +22,8 @@
 
     protected override async Task OnInitializedAsync()
     {
-        QuizState.OnQuizRequested += HandleQuizRequested;
-        FocusMode.OnFocusModeChanged += StateHasChanged;
+        QuizState.OnQuizRequested += HandleQuizRequestedAsync;
+        FocusMode.OnFocusModeChanged += HandleUpdate;
         await FocusMode.InitializeAsync();
     }
 
@@ -54,16 +54,18 @@
         }
     }
 
-    private void HandleQuizRequested(string blockId)
+    private async Task HandleQuizRequestedAsync(string blockId)
     {
         _activeQuizBlockId = blockId;
-        StateHasChanged();
+        await InvokeAsync(StateHasChanged);
     }
 
+    private Task HandleUpdate() => InvokeAsync(StateHasChanged);
+
     public async ValueTask DisposeAsync()
     {
-        QuizState.OnQuizRequested -= HandleQuizRequested;
-        FocusMode.OnFocusModeChanged -= StateHasChanged;
+        QuizState.OnQuizRequested -= HandleQuizRequestedAsync;
+        FocusMode.OnFocusModeChanged -= HandleUpdate;
         
         if (_interopModule != null && _keydownHandler != null)
         {

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

@@ -1,8 +1,8 @@
 .home-reader-container {
     width: 100%;
+    height: 100%;
     max-width: 800px;
     margin: 0 auto;
-    padding: 2rem;
     transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
 }
 

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

@@ -1,5 +1,10 @@
-@page "/not-found"
-@layout MainLayout
-
-<h3>Not Found</h3>
-<p>Sorry, the content you are looking for does not exist.</p>
+@page "/not-found"
+@layout Layout.MainLayout
+
+<div class="not-found-preloader">
+    <div class="preloader-robot">
+        <NexusIcon Name="robot" Size="64" class="neon-pulse" />
+        <div class="scan-line"></div>
+    </div>
+    <NexusTypography Variant="NexusTypography.TypographyVariant.UI">Synchronizowanie przestrzeni Nexus...</NexusTypography>
+</div>

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

@@ -0,0 +1,42 @@
+.not-found-preloader {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    height: 60vh;
+    gap: 2rem;
+}
+
+.preloader-robot {
+    position: relative;
+    padding: 1rem;
+}
+
+.scan-line {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 2px;
+    background: var(--nexus-neon);
+    box-shadow: 0 0 10px var(--nexus-neon);
+    animation: scan 2s linear infinite;
+}
+
+@keyframes scan {
+    0% { top: 0; }
+    50% { top: 100%; }
+    100% { top: 0; }
+}
+
+.neon-pulse {
+    color: var(--nexus-neon);
+    filter: drop-shadow(0 0 5px var(--nexus-neon));
+    animation: pulse 2s infinite;
+}
+
+@keyframes pulse {
+    0% { transform: scale(1); opacity: 1; }
+    50% { transform: scale(1.1); opacity: 0.8; }
+    100% { transform: scale(1); opacity: 1; }
+}

src/NexusReader.UI.Shared/Routes.razor

@@ -9,6 +9,9 @@
                 </AuthorizeRouteView>
                 <FocusOnNavigate RouteData="@routeData" Selector="h1" />
             </Found>
+            <NotFound>
+                <NexusReader.UI.Shared.Pages.NotFound />
+            </NotFound>
         </Router>
     </ChildContent>
     <ErrorContent Context="ex">

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

@@ -6,7 +6,7 @@ public sealed class FocusModeService : IFocusModeService
 {
     private readonly IJSRuntime _jsRuntime;
     public bool IsFocusModeActive { get; private set; }
-    public event Action? OnFocusModeChanged;
+    public event Func<Task>? OnFocusModeChanged;
 
     public FocusModeService(IJSRuntime jsRuntime)
     {
@@ -21,7 +21,7 @@ public sealed class FocusModeService : IFocusModeService
             if (value == "true" && !IsFocusModeActive)
             {
                 IsFocusModeActive = true;
-                OnFocusModeChanged?.Invoke();
+                if (OnFocusModeChanged != null) await OnFocusModeChanged();
             }
         }
         catch
@@ -33,7 +33,7 @@ public sealed class FocusModeService : IFocusModeService
     public async Task ToggleAsync()
     {
         IsFocusModeActive = !IsFocusModeActive;
-        OnFocusModeChanged?.Invoke();
+        if (OnFocusModeChanged != null) await OnFocusModeChanged();
 
         try
         {

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

@@ -3,7 +3,7 @@ namespace NexusReader.UI.Shared.Services;
 public interface IFocusModeService
 {
     bool IsFocusModeActive { get; }
-    event Action? OnFocusModeChanged;
+    event Func<Task>? OnFocusModeChanged;
     Task InitializeAsync();
     Task ToggleAsync();
 }

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

@@ -8,12 +8,12 @@ public interface IKnowledgeGraphService
     string? ActiveNodeId { get; }
     bool IsLoading { get; }
     
-    event Action? OnGraphUpdated;
-    event Action<string>? OnActiveNodeChanged;
-    event Action<bool>? OnLoadingChanged;
+    event Func<Task>? OnGraphUpdated;
+    event Func<string, Task>? OnActiveNodeChanged;
+    event Func<bool, Task>? OnLoadingChanged;
 
-    void UpdateGraph(GraphDataDto newData);
-    void SetActiveNode(string nodeId);
-    void SetLoading(bool isLoading);
-    void Clear();
+    Task UpdateGraph(GraphDataDto newData);
+    Task SetActiveNode(string nodeId);
+    Task SetLoading(bool isLoading);
+    Task Clear();
 }

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

@@ -9,11 +9,11 @@ public interface IQuizStateService
     bool IsHydrating { get; }
     bool HasNewQuiz { get; }
     
-    event Action<string>? OnQuizRequested;
-    event Action? OnQuizUpdated;
+    event Func<string, Task>? OnQuizRequested;
+    event Func<Task>? OnQuizUpdated;
     
-    void RequestQuiz(string blockId);
-    void SetQuiz(string? blockId, QuizDto quiz);
-    void SetHydrating(bool hydrating);
-    void MarkQuizAsSeen();
+    Task RequestQuiz(string blockId);
+    Task SetQuiz(string? blockId, QuizDto? quiz);
+    Task SetHydrating(bool hydrating);
+    Task MarkQuizAsSeen();
 }

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

@@ -2,15 +2,15 @@ namespace NexusReader.UI.Shared.Services;
 
 public interface IReaderInteractionService
 {
-    event Action<string>? OnNodeSelected;
-    event Action<string>? OnScrollToBlockRequested;
-    event Action<string>? OnHighlightBlockRequested;
-    event Action<string, string, SelectionCoordinates>? OnTextSelected;
+    event Func<string, Task>? OnNodeSelected;
+    event Func<string, Task>? OnScrollToBlockRequested;
+    event Func<string, Task>? OnHighlightBlockRequested;
+    event Func<string, string, SelectionCoordinates, Task>? OnTextSelected;
 
-    void NotifyNodeSelected(string nodeId);
-    void RequestScrollToBlock(string blockId);
-    void RequestHighlightBlock(string blockId);
-    void NotifyTextSelected(string text, string blockId, SelectionCoordinates coords);
+    Task NotifyNodeSelected(string nodeId);
+    Task RequestScrollToBlock(string blockId);
+    Task RequestHighlightBlock(string blockId);
+    Task NotifyTextSelected(string text, string blockId, SelectionCoordinates coords);
 }
 
 public record SelectionCoordinates(double Top, double Left, double Width);

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

@@ -6,6 +6,6 @@ public interface ISyncService
 {
     Task<Result> InitializeAsync();
     Task<Result> UpdateProgressAsync(string pageId);
-    event Action<string, DateTime> OnProgressReceived;
+    event Func<string, DateTime, Task> OnProgressReceived;
     Task DisposeAsync();
 }

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

@@ -3,6 +3,6 @@ namespace NexusReader.UI.Shared.Services;
 public interface IThemeService
 {
     bool IsLightMode { get; }
-    event Action? OnThemeChanged;
-    void ToggleTheme();
+    event Func<Task>? OnThemeChanged;
+    Task ToggleTheme();
 }

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

@@ -36,10 +36,10 @@ public sealed partial class KnowledgeCoordinator : IDisposable
         _interactionService.OnNodeSelected += HandleNodeSelected;
     }
 
-    private void HandleNodeSelected(string nodeId)
+    private async Task HandleNodeSelected(string nodeId)
     {
-        _interactionService.RequestScrollToBlock(nodeId);
-        _interactionService.RequestHighlightBlock(nodeId);
+        await _interactionService.RequestScrollToBlock(nodeId);
+        await _interactionService.RequestHighlightBlock(nodeId);
     }
 
     public async Task ProcessFullPageAsync(string fullContent, string tenantId = "global")
@@ -48,8 +48,8 @@ public sealed partial class KnowledgeCoordinator : IDisposable
 
         LogGeneratingGraph(tenantId);
         
-        _graphService.Clear();
-        _graphService.SetLoading(true);
+        await _graphService.Clear();
+        await _graphService.SetLoading(true);
         
         try
         {
@@ -59,7 +59,7 @@ public sealed partial class KnowledgeCoordinator : IDisposable
                 var packet = result.Value;
                 if (packet.Graph != null)
                 {
-                    _graphService.UpdateGraph(packet.Graph);
+                    await _graphService.UpdateGraph(packet.Graph);
                     OnGraphUpdated?.Invoke(packet.Graph);
                     await _platformService.VibrateSuccessAsync();
                 }
@@ -71,15 +71,15 @@ public sealed partial class KnowledgeCoordinator : IDisposable
         }
     }
 
-    public void OnBlockReached(string blockId, string content)
+    public async Task OnBlockReachedAsync(string blockId, string content)
     {
         // Only update active node for "TU JESTEŚ" logic, do NOT trigger highlight here
-        _graphService.SetActiveNode(blockId);
+        await _graphService.SetActiveNode(blockId);
     }
 
     public async Task<KnowledgePacket?> RequestSummaryAndQuizAsync(string content, string tenantId = "global")
     {
-        _quizService.SetHydrating(true);
+        await _quizService.SetHydrating(true);
         LogRequestingSummary(tenantId);
         try
         {
@@ -91,7 +91,7 @@ public sealed partial class KnowledgeCoordinator : IDisposable
                     .Select(q => new QuizQuestionDto(q.Question, q.Options, q.CorrectIndex))
                     .ToList();
                 
-                _quizService.SetQuiz(null, new QuizDto(quizQuestions));
+                await _quizService.SetQuiz(null, new QuizDto(quizQuestions));
                 await _platformService.VibrateSuccessAsync();
                 return packet;
             }
@@ -104,15 +104,15 @@ public sealed partial class KnowledgeCoordinator : IDisposable
         }
         finally
         {
-            _quizService.SetHydrating(false);
+            await _quizService.SetHydrating(false);
         }
         return null;
     }
 
-    public void Clear()
+    public async Task ClearAsync()
     {
-        _graphService.Clear();
-        _quizService.SetQuiz(null, null);
+        await _graphService.Clear();
+        await _quizService.SetQuiz(null, null);
     }
 
     public void Dispose()

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

@@ -8,36 +8,36 @@ public sealed class KnowledgeGraphService : IKnowledgeGraphService
     public string? ActiveNodeId { get; private set; }
     public bool IsLoading { get; private set; }
 
-    public event Action? OnGraphUpdated;
-    public event Action<string>? OnActiveNodeChanged;
-    public event Action<bool>? OnLoadingChanged;
+    public event Func<Task>? OnGraphUpdated;
+    public event Func<string, Task>? OnActiveNodeChanged;
+    public event Func<bool, Task>? OnLoadingChanged;
 
-    public void UpdateGraph(GraphDataDto newData)
+    public async Task UpdateGraph(GraphDataDto newData)
     {
         CurrentGraphData = newData;
         IsLoading = false;
-        OnLoadingChanged?.Invoke(false);
-        OnGraphUpdated?.Invoke();
+        if (OnLoadingChanged != null) await OnLoadingChanged(false);
+        if (OnGraphUpdated != null) await OnGraphUpdated();
     }
 
-    public void SetActiveNode(string nodeId)
+    public async Task SetActiveNode(string nodeId)
     {
         if (ActiveNodeId == nodeId) return;
         ActiveNodeId = nodeId;
-        OnActiveNodeChanged?.Invoke(nodeId);
+        if (OnActiveNodeChanged != null) await OnActiveNodeChanged(nodeId);
     }
 
-    public void SetLoading(bool isLoading)
+    public async Task SetLoading(bool isLoading)
     {
         IsLoading = isLoading;
-        OnLoadingChanged?.Invoke(isLoading);
+        if (OnLoadingChanged != null) await OnLoadingChanged(isLoading);
     }
 
-    public void Clear()
+    public async Task Clear()
     {
         CurrentGraphData = null;
         ActiveNodeId = null;
         IsLoading = false;
-        OnGraphUpdated?.Invoke();
+        if (OnGraphUpdated != null) await OnGraphUpdated();
     }
 }

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

@@ -9,34 +9,34 @@ public sealed class QuizStateService : IQuizStateService
     public bool IsHydrating { get; private set; }
     public bool HasNewQuiz { get; private set; }
 
-    public event Action<string>? OnQuizRequested;
-    public event Action? OnQuizUpdated;
+    public event Func<string, Task>? OnQuizRequested;
+    public event Func<Task>? OnQuizUpdated;
 
-    public void RequestQuiz(string blockId)
+    public async Task RequestQuiz(string blockId)
     {
         CurrentQuizBlockId = blockId;
-        OnQuizRequested?.Invoke(blockId);
+        if (OnQuizRequested != null) await OnQuizRequested(blockId);
     }
 
-    public void SetQuiz(string? blockId, QuizDto quiz)
+    public async Task SetQuiz(string? blockId, QuizDto? quiz)
     {
         CurrentQuizBlockId = blockId;
         CurrentQuiz = quiz;
         IsHydrating = false;
-        HasNewQuiz = true;
-        OnQuizUpdated?.Invoke();
+        HasNewQuiz = quiz != null;
+        if (OnQuizUpdated != null) await OnQuizUpdated();
     }
 
-    public void SetHydrating(bool hydrating)
+    public async Task SetHydrating(bool hydrating)
     {
         IsHydrating = hydrating;
-        OnQuizUpdated?.Invoke();
+        if (OnQuizUpdated != null) await OnQuizUpdated();
     }
 
-    public void MarkQuizAsSeen()
+    public async Task MarkQuizAsSeen()
     {
         if (!HasNewQuiz) return;
         HasNewQuiz = false;
-        OnQuizUpdated?.Invoke();
+        if (OnQuizUpdated != null) await OnQuizUpdated();
     }
 }

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

@@ -2,28 +2,28 @@ namespace NexusReader.UI.Shared.Services;
 
 public sealed class ReaderInteractionService : IReaderInteractionService
 {
-    public event Action<string>? OnNodeSelected;
-    public event Action<string>? OnScrollToBlockRequested;
-    public event Action<string>? OnHighlightBlockRequested;
-    public event Action<string, string, SelectionCoordinates>? OnTextSelected;
+    public event Func<string, Task>? OnNodeSelected;
+    public event Func<string, Task>? OnScrollToBlockRequested;
+    public event Func<string, Task>? OnHighlightBlockRequested;
+    public event Func<string, string, SelectionCoordinates, Task>? OnTextSelected;
 
-    public void NotifyNodeSelected(string nodeId)
+    public async Task NotifyNodeSelected(string nodeId)
     {
-        OnNodeSelected?.Invoke(nodeId);
+        if (OnNodeSelected != null) await OnNodeSelected(nodeId);
     }
 
-    public void RequestScrollToBlock(string blockId)
+    public async Task RequestScrollToBlock(string blockId)
     {
-        OnScrollToBlockRequested?.Invoke(blockId);
+        if (OnScrollToBlockRequested != null) await OnScrollToBlockRequested(blockId);
     }
 
-    public void RequestHighlightBlock(string blockId)
+    public async Task RequestHighlightBlock(string blockId)
     {
-        OnHighlightBlockRequested?.Invoke(blockId);
+        if (OnHighlightBlockRequested != null) await OnHighlightBlockRequested(blockId);
     }
 
-    public void NotifyTextSelected(string text, string blockId, SelectionCoordinates coords)
+    public async Task NotifyTextSelected(string text, string blockId, SelectionCoordinates coords)
     {
-        OnTextSelected?.Invoke(text, blockId, coords);
+        if (OnTextSelected != null) await OnTextSelected(text, blockId, coords);
     }
 }

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

@@ -14,7 +14,7 @@ public class SyncService : ISyncService, IAsyncDisposable
     private bool _isInitialized;
     private CancellationTokenSource? _debounceCts;
 
-    public event Action<string, DateTime>? OnProgressReceived;
+    public event Func<string, DateTime, Task>? OnProgressReceived;
 
     public SyncService(
         HttpClient httpClient,
@@ -44,9 +44,9 @@ public class SyncService : ISyncService, IAsyncDisposable
             .WithAutomaticReconnect()
             .Build();
 
-        _hubConnection.On<string, DateTime>("ProgressUpdated", (pageId, timestamp) =>
+        _hubConnection.On<string, DateTime>("ProgressUpdated", async (pageId, timestamp) =>
         {
-            OnProgressReceived?.Invoke(pageId, timestamp);
+            if (OnProgressReceived != null) await OnProgressReceived(pageId, timestamp);
         });
 
         try

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

@@ -3,11 +3,11 @@ namespace NexusReader.UI.Shared.Services;
 public sealed class ThemeService : IThemeService
 {
     public bool IsLightMode { get; private set; } = false;
-    public event Action? OnThemeChanged;
+    public event Func<Task>? OnThemeChanged;
 
-    public void ToggleTheme()
+    public async Task ToggleTheme()
     {
         IsLightMode = !IsLightMode;
-        OnThemeChanged?.Invoke();
+        if (OnThemeChanged != null) await OnThemeChanged();
     }
 }

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

@@ -1,10 +1,13 @@
 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;
+
 let simulation;
 let zoomBehavior;
 let svgElement;
 
-let node, link, rootGroup, badge, width, height, currentDotNetHelper, resizeHandler;
+let node, link, rootGroup, badge, width, height, currentDotNetHelper, resizeObserver;
 
 export function mount(containerId, data, dotNetHelper) {
     const container = document.getElementById(containerId);
@@ -18,7 +21,8 @@ export function mount(containerId, data, dotNetHelper) {
     svgElement = d3.select(container).append("svg")
         .attr("viewBox", [0, 0, width, height])
         .attr("width", "100%")
-        .attr("height", "100%");
+        .attr("height", "100%")
+        .style("background", "radial-gradient(circle, #1a1a1a 0%, #121212 100%)");
 
     // Radial gradient for Nebula effect
     const defs = svgElement.append("defs");
@@ -66,14 +70,19 @@ export function mount(containerId, data, dotNetHelper) {
     
     svgElement.call(zoomBehavior).on("wheel.zoom", null);
 
-    resizeHandler = () => handleResize(containerId);
-    window.addEventListener('resize', resizeHandler);
+    // Use ResizeObserver for more reliable container size tracking
+    resizeObserver = new ResizeObserver(entries => {
+        for (let entry of entries) {
+            handleResize(containerId);
+        }
+    });
+    resizeObserver.observe(container);
 
     simulation = d3.forceSimulation()
         .force("link", d3.forceLink().id(d => d.id).distance(120))
         .force("charge", d3.forceManyBody().strength(-400))
         .force("center", d3.forceCenter(width / 2, height / 2))
-        .force("collide", d3.forceCollide().radius(50));
+        .force("collide", d3.forceCollide().radius(d => (getPillWidth(d) / 2) + 20));
 
     simulation.on("tick", () => {
         if (link) {
@@ -86,7 +95,14 @@ export function mount(containerId, data, dotNetHelper) {
         }
 
         if (node) {
-            node.attr("transform", d => `translate(${d.x},${d.y})`);
+            node.attr("transform", d => {
+                // Keep within bounds with padding
+                const pillWidth = getPillWidth(d);
+                const halfWidth = pillWidth / 2;
+                d.x = Math.max(halfWidth + 20, Math.min(width - halfWidth - 20, d.x));
+                d.y = Math.max(35, Math.min(height - 35, d.y));
+                return `translate(${d.x},${d.y})`;
+            });
         }
         
         if (badge && badge.style("display") !== "none") {
@@ -134,9 +150,10 @@ export function updateData(data) {
                 .attr("fill", "none")
                 .attr("stroke-width", d => d.relationType === 'Defines' ? 2 : 1)
                 .attr("stroke-dasharray", d => d.relationType === 'References' ? "5,5" : "0")
-                .call(e => e.transition().duration(500).attr("opacity", 1)),
+                .style("opacity", 0)
+                .call(enter => enter.transition().duration(500).style("opacity", 1)),
             update => update,
-            exit => exit.remove()
+            exit => exit.transition().duration(500).style("opacity", 0).remove()
         );
 
     // Update Nodes
@@ -146,8 +163,9 @@ export function updateData(data) {
         .join(
             enter => {
                 const g = enter.append("g")
-                    .attr("class", "node-group")
+                    .attr("class", "node-group neon-flash-node")
                     .style("cursor", "pointer")
+                    .style("opacity", 0)
                     .on("click", (e, d) => {
                         currentDotNetHelper.invokeMethodAsync('OnNodeClicked', d.id);
                         setActiveNode(d.id);
@@ -162,16 +180,15 @@ export function updateData(data) {
                         if (d.type === 'Rule') return '#ff4444';
                         return "url(#nebulaGlow)";
                     })
-                    .attr("opacity", 0)
-                    .transition().duration(1000).attr("opacity", d => d.group === 'current' ? 0.6 : 0.2);
+                    .attr("opacity", d => d.group === 'current' ? 0.6 : 0.2);
 
                 g.append("rect")
                     .attr("class", "node-pill")
-                    .attr("x", d => -(d.label.length * 4 + 10))
-                    .attr("y", -12)
-                    .attr("width", d => d.label.length * 8 + 20)
-                    .attr("height", 24)
-                    .attr("rx", 12)
+                    .attr("x", d => -getPillWidth(d) / 2)
+                    .attr("y", -15)
+                    .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)';
@@ -181,21 +198,29 @@ export function updateData(data) {
                     .attr("stroke-width", 1);
 
                 g.append("text")
-                    .text(d => d.label)
+                    .text(d => getDisplayLabel(d))
                     .attr("text-anchor", "middle")
-                    .attr("y", 4)
+                    .attr("y", 5)
                     .attr("fill", d => d.type === 'Definition' ? 'var(--nexus-accent)' : '#ccc')
                     .attr("font-size", "0.8rem");
+
+                g.append("title")
+                    .text(d => d.label);
+                
+                g.transition().duration(500).style("opacity", 1);
                 
                 return g;
             },
-            update => update,
-            exit => exit.remove()
+            update => update.classed("neon-flash-node", false),
+            exit => exit.transition().duration(500).style("opacity", 0).remove()
         );
 
     simulation.nodes(data.nodes);
     simulation.force("link").links(data.links);
     simulation.alpha(0.5).restart();
+
+    // Trigger zoom to fit after a short delay to allow simulation to settle
+    setTimeout(zoomToFit, 100);
 }
 
 function drag(simulation) {
@@ -222,32 +247,59 @@ function drag(simulation) {
 export function setActiveNode(nodeId) {
     if (!svgElement || !node) return;
     
+    // Safety check: ensure we only target the first occurrence if IDs are duplicated
     const targetNode = node.filter(d => d.id === nodeId);
-    if (targetNode.empty()) return;
+    if (targetNode.empty()) {
+        dimNodes(null);
+        badge.style("display", "none");
+        return;
+    }
 
-    const d = targetNode.datum();
+    const firstMatch = targetNode.filter((d, i) => i === 0);
+    const d = firstMatch.datum();
     
     // Reset all active classes
     rootGroup.selectAll(".node-pill").classed("nexus-node-active", false);
-    targetNode.select(".node-pill").classed("nexus-node-active", true);
+    firstMatch.select(".node-pill").classed("nexus-node-active", true);
 
     // Position badge
     badge.style("display", "block").datum(d);
     badge.attr("transform", `translate(${d.x},${d.y})`);
 
-    // Smooth transition
+    // Dim others (only exact matches for nodeId will be fully opaque)
+    dimNodes(nodeId);
+
+    // Smooth transition to the first matching node
     svgElement.transition().duration(1000).call(
         zoomBehavior.transform,
         d3.zoomIdentity.translate(width / 2, height / 2).scale(1.2).translate(-d.x, -d.y)
     );
 }
 
+export function dimNodes(activeNodeId) {
+    if (!node) return;
+    
+    node.transition().duration(500)
+        .style("opacity", d => (activeNodeId === null || d.id === activeNodeId) ? 1 : 0.4);
+    
+    if (link) {
+        link.transition().duration(500)
+            .style("opacity", d => {
+                if (activeNodeId === null) return 1;
+                // Check if this link is connected to the active node
+                const sourceId = typeof d.source === 'object' ? d.source.id : d.source;
+                const targetId = typeof d.target === 'object' ? d.target.id : d.target;
+                return (sourceId === activeNodeId || targetId === activeNodeId) ? 1 : 0.1;
+            });
+    }
+}
+
 export function unmount(containerId) {
     if (simulation) {
         simulation.stop();
     }
-    if (resizeHandler) {
-        window.removeEventListener('resize', resizeHandler);
+    if (resizeObserver) {
+        resizeObserver.disconnect();
     }
     const container = document.getElementById(containerId);
     if (container) {
@@ -293,9 +345,43 @@ export function zoomOut() {
 }
 
 export function zoomReset() {
-    if (svgElement && zoomBehavior) {
-        svgElement.transition().duration(500).call(zoomBehavior.transform, d3.zoomIdentity);
-    }
+    zoomToFit();
+}
+
+export function zoomToFit() {
+    if (!node || node.empty() || !svgElement || !zoomBehavior) return;
+
+    // Get the actual bounding box of the nodes
+    let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
+    node.each(d => {
+        const pw = getPillWidth(d) / 2;
+        minX = Math.min(minX, d.x - pw);
+        maxX = Math.max(maxX, d.x + pw);
+        minY = Math.min(minY, d.y - 15);
+        maxY = Math.max(maxY, d.y + 15);
+    });
+
+    if (minX === Infinity) return;
+
+    const graphWidth = maxX - minX;
+    const graphHeight = maxY - minY;
+    const midX = (minX + maxX) / 2;
+    const midY = (minY + maxY) / 2;
+
+    const padding = 60;
+    const scale = Math.min(
+        (width - padding) / graphWidth,
+        (height - padding) / graphHeight,
+        1.2 // Max scale
+    );
+
+    svgElement.transition().duration(750).call(
+        zoomBehavior.transform,
+        d3.zoomIdentity
+            .translate(width / 2, height / 2)
+            .scale(scale)
+            .translate(-midX, -midY)
+    );
 }
 
 export function clear() {

src/NexusReader.Web.Client/Handlers/AuthenticationHeaderHandler.cs

@@ -0,0 +1,27 @@
+using System.Net.Http.Headers;
+using NexusReader.Application.Abstractions.Services;
+
+namespace NexusReader.Web.Client.Handlers;
+
+public class AuthenticationHeaderHandler : DelegatingHandler
+{
+    private readonly INativeStorageService _storageService;
+    private const string TokenKey = "nexus_auth_token";
+
+    public AuthenticationHeaderHandler(INativeStorageService storageService)
+    {
+        _storageService = storageService;
+    }
+
+    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+    {
+        var tokenResult = await _storageService.GetSecureString(TokenKey);
+        
+        if (tokenResult.IsSuccess && !string.IsNullOrEmpty(tokenResult.Value))
+        {
+            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", tokenResult.Value);
+        }
+
+        return await base.SendAsync(request, cancellationToken);
+    }
+}

src/NexusReader.Web.Client/NexusReader.Web.Client.csproj

@@ -12,6 +12,7 @@
   <ItemGroup>
     <PackageReference Include="MediatR" Version="12.1.1" />
     <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly" Version="10.0.7" />
+    <PackageReference Include="Microsoft.Extensions.Http" Version="10.0.7" />
   </ItemGroup>
 
   <ItemGroup>

src/NexusReader.Web.Client/Program.cs

@@ -4,6 +4,9 @@ using NexusReader.Application.Abstractions.Services;
 using NexusReader.Web.Client.Services;
 using NexusReader.UI.Shared.Services;
 using NexusReader.Application;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.AI;
+using NexusReader.Data.Persistence;
 
 
 var builder = WebAssemblyHostBuilder.CreateDefault(args);
@@ -30,9 +33,33 @@ builder.Services.AddCascadingAuthenticationState();
 
 // AI & Content Services
 builder.Services.AddScoped<IKnowledgeService, WasmKnowledgeService>();
-builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });
+
+builder.Services.AddTransient<NexusReader.Web.Client.Handlers.AuthenticationHeaderHandler>();
+builder.Services.AddHttpClient("NexusAPI", client => 
+{
+    client.BaseAddress = new Uri(builder.HostEnvironment.BaseAddress);
+}).AddHttpMessageHandler<NexusReader.Web.Client.Handlers.AuthenticationHeaderHandler>();
+
+builder.Services.AddScoped(sp => sp.GetRequiredService<IHttpClientFactory>().CreateClient("NexusAPI"));
+
+// Dummy registrations for server-only handlers to satisfy DI validation
+builder.Services.AddSingleton<IDbContextFactory<AppDbContext>>(new ThrowingDbContextFactory());
+builder.Services.AddSingleton<IEmbeddingGenerator<string, Embedding<float>>>(new ThrowingEmbeddingGenerator());
 
 builder.Services.AddApplication();
 builder.Services.AddScoped<IEpubService, WasmEpubService>();
 
 await builder.Build().RunAsync();
+
+public class ThrowingDbContextFactory : IDbContextFactory<AppDbContext>
+{
+    public AppDbContext CreateDbContext() => throw new NotSupportedException("DbContext cannot be used in WASM client.");
+}
+
+public class ThrowingEmbeddingGenerator : IEmbeddingGenerator<string, Embedding<float>>
+{
+    public void Dispose() { }
+    public Task<GeneratedEmbeddings<Embedding<float>>> GenerateAsync(IEnumerable<string> values, EmbeddingGenerationOptions? options = null, CancellationToken cancellationToken = default) 
+        => throw new NotSupportedException("Embedding generation cannot be used in WASM client.");
+    public object? GetService(Type serviceType, object? serviceKey = null) => null;
+}

src/NexusReader.Web.New/Program.cs

@@ -96,6 +96,18 @@ builder.Services.ConfigureApplicationCookie(options =>
     options.Cookie.HttpOnly = true;
     options.ExpireTimeSpan = TimeSpan.FromDays(30);
     options.SlidingExpiration = true;
+    options.Events.OnRedirectToLogin = context =>
+    {
+        if (context.Request.Path.StartsWithSegments("/api"))
+        {
+            context.Response.StatusCode = 401;
+        }
+        else
+        {
+            context.Response.Redirect(context.RedirectUri);
+        }
+        return Task.CompletedTask;
+    };
 });
 
 builder.Services.Configure<IdentityOptions>(options =>