feat(ui): implement premium mobile-first reader toolbar, bottom navigation, and auth ux stabilization (#61)

# Description

This Pull Request integrates the premium mobile-first layout enhancements, a responsive, full-bleed Reader Toolbar, and critical authorization flow stabilizations for the NexusReader Blazor application (targeting .NET 10 with Native AOT compatibility).

Resolves #62
Resolves #63
Resolves #15

## Key Changes

### 📱 1. Mobile-First Reader Layout & Toolbar
- **Full-Bleed Responsive Layout**: Redesigned `ReaderLayout` to feature a premium mobile-first three-tab bottom navigation system (Chapters, Graph, Assistant) and a glassmorphic floating action button (FAB) for the AI assistant.
- **Header & Escaping Routes**: Built `MobileReaderToolbar` with seamless exit paths back to the "Pulpit" (dashboard) and smooth transitions.
- **Custom Iconography**: Added the custom `NexusIcon` component supporting dynamic theme styling and responsive layouts without relying on external CSS frameworks.

### 🔐 2. Authentication Flow UX Stabilization
- **WASM Transition Hydration**: Implemented `AuthenticationStatePersister` and loading preloaders to eliminate authorization race conditions during Blazor WASM interactive hydration.
- **AOT-Compatible JWT Validation**: Integrated a robust, AOT-compatible `JwtTokenValidator` with unit tests (`JwtTokenValidatorTests.cs`) to cleanly parse claims without throwing performance-heavy runtime exceptions.
- **Secure Header Propagation**: Standardized token transmission in WASM (`AuthenticationHeaderHandler.cs`) and MAUI Hybrid client layers (`MobileAuthenticationHeaderHandler.cs`), ensuring cookies are correctly propagated.

### 📊 3. D3.js Knowledge Graph & Interaction
- **Dynamic Viewport Synchronization**: Refactored `knowledgeGraph.js` to ensure the SVG graph behaves correctly under flexbox containment, handles panel expansion/collapse gracefully, and avoids infinite loop redraws.
- **Interaction Hook**: Connected graph node clicks directly to chapter jumps via a new `IReaderInteractionService` abstraction.

### 🏗️ 4. Infrastructure & Central Package Management (CPM)
- **Beta Deployment Configuration**: Added `.env.test.template`, `docker-compose.test.yml`, and `appsettings.Test.json` with hardened environment security guards.
- **Docker-Compose Cache Optimization**: Maintained CPM consistency during multi-stage Docker builds.

## Verification & Build Results
- Run a successful local build check:
  ```bash
  dotnet build NexusReader.slnx --no-restore
  ```
  **Status**: Successfully completed with `0` compilation errors.

---------

Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Reviewed-on: #61
Co-authored-by: Antigravity <antigravity@google.com>
Co-committed-by: Antigravity <antigravity@google.com>

.env.test.template

@@ -32,7 +32,7 @@ GOOGLE_CLIENT_SECRET=placeholder
 GOOGLE_AI_API_KEY=placeholder
 
 # === Admin Seed Password ===
-NEXUS_ADMIN_PASSWORD=aQ13EdSw2
+NEXUS_ADMIN_PASSWORD=CHANGE_ME
 
 # === Non-standard ports for auxiliary services ===
 QDRANT_HTTP_PORT=6343

docker-compose.test.yml

@@ -36,7 +36,7 @@ services:
       - Authentication__Google__ClientId=${GOOGLE_CLIENT_ID:-placeholder}
       - Authentication__Google__ClientSecret=${GOOGLE_CLIENT_SECRET:-placeholder}
       - Ai__Google__ApiKey=${GOOGLE_AI_API_KEY:-placeholder}
-      - NEXUS_ADMIN_PASSWORD=${NEXUS_ADMIN_PASSWORD:-aQ13EdSw2}
+      - NEXUS_ADMIN_PASSWORD=${NEXUS_ADMIN_PASSWORD:?NEXUS_ADMIN_PASSWORD is required}
     depends_on:
       db:
         condition: service_healthy

src/NexusReader.Data/Persistence/DbInitializer.cs

@@ -1,5 +1,6 @@
 using Microsoft.AspNetCore.Identity;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Configuration;
 using NexusReader.Domain.Entities;
 using System;
 using System.Linq;
@@ -16,6 +17,7 @@ public static class DbInitializer
         using var scope = serviceProvider.CreateScope();
         var passwordHasher = scope.ServiceProvider.GetRequiredService<IPasswordHasher<NexusUser>>();
         var dbContextFactory = scope.ServiceProvider.GetRequiredService<IDbContextFactory<AppDbContext>>();
+        var configuration = scope.ServiceProvider.GetService<IConfiguration>();
         using var dbContext = await dbContextFactory.CreateDbContextAsync();
 
         try
@@ -68,7 +70,10 @@ public static class DbInitializer
                     SecurityStamp = Guid.NewGuid().ToString()
                 };
 
-                var adminPassword = Environment.GetEnvironmentVariable("NEXUS_ADMIN_PASSWORD") ?? "Admin123!";
+                var adminPassword = configuration?["Nexus:AdminPassword"] 
+                                    ?? configuration?["NEXUS_ADMIN_PASSWORD"] 
+                                    ?? Environment.GetEnvironmentVariable("NEXUS_ADMIN_PASSWORD") 
+                                    ?? "Admin123!";
                 adminUser.PasswordHash = passwordHasher.HashPassword(adminUser, adminPassword);
 
                 dbContext.Users.Add(adminUser);

src/NexusReader.Maui/MauiProgram.cs

@@ -69,6 +69,7 @@ public static class MauiProgram
 			builder.Services.AddScoped<IReaderNavigationService, ReaderNavigationService>();
 			builder.Services.AddScoped<IKnowledgeGraphService, KnowledgeGraphService>();
 			builder.Services.AddScoped<IReaderInteractionService, ReaderInteractionService>();
+			builder.Services.AddScoped<IReaderStateService, ReaderStateService>();
 			builder.Services.AddScoped<KnowledgeCoordinator>();
 			builder.Services.AddScoped<ISyncService, SyncService>();
 			builder.Services.AddScoped<IIdentityService, IdentityService>();

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

@@ -10,6 +10,7 @@
             <line x1="8" y1="2" x2="8" y2="18" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
             <line x1="16" y1="6" x2="16" y2="22" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
             break;
+        case "share":
         case "share-2":
             <circle cx="18" cy="5" r="3" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
             <circle cx="6" cy="12" r="3" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
@@ -45,6 +46,7 @@
             <line x1="3" y1="9" x2="21" y2="9" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
             <line x1="9" y1="21" x2="9" y2="9" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
             break;
+        case "book":
         case "book-open":
             <path d="M2 3h6a4 4 0 0 1 4 4v14a3 3 0 0 0-3-3H2z" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
             <path d="M22 3h-6a4 4 0 0 0-4 4v14a3 3 0 0 1 3-3h7z" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
@@ -86,6 +88,17 @@
         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;
+        case "chevron-left":
+            <polyline points="15 18 9 12 15 6" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
+            break;
+        case "chevron-right":
+            <polyline points="9 18 15 12 9 6" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
+            break;
+        case "x":
+        case "close":
+            <line x1="18" y1="6" x2="6" y2="18" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" />
+            <line x1="6" y1="6" x2="18" y2="18" 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/SelectionAiPanel.razor

@@ -1,4 +1,5 @@
 @using NexusReader.UI.Shared.Services
+@using NexusReader.UI.Shared.Models
 @using NexusReader.Application.DTOs.AI
 @inject KnowledgeCoordinator Coordinator
 @inject IReaderInteractionService InteractionService

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

@@ -0,0 +1,351 @@
+@using NexusReader.Application.DTOs.AI
+@using NexusReader.Application.Abstractions.Services
+@using NexusReader.Application.DTOs.User
+@using NexusReader.UI.Shared.Components.Atoms
+@using NexusReader.UI.Shared.Services
+@using NexusReader.UI.Shared.Models
+@using System.Net.Http.Json
+@namespace NexusReader.UI.Shared.Components.Organisms
+@inject HttpClient Http
+@inject IKnowledgeService KnowledgeService
+@inject AuthenticationStateProvider AuthStateProvider
+@inject IReaderNavigationService NavigationService
+
+<div class="global-intelligence-sheet @(IsOpen ? "is-open" : "")">
+    <div class="sheet-backdrop" @onclick="HandleClose"></div>
+    <div class="sheet-content">
+        <div class="sheet-drag-handle"></div>
+        
+        <header class="sheet-header">
+            <div class="header-main">
+                <div class="ai-avatar-badge">
+                    <NexusIcon Name="robot" Size="20" Class="neon-glow" />
+                </div>
+                <div class="header-info">
+                    <h3>Asystent AI Nexus</h3>
+                    <p class="subtitle">Zadawaj pytania do swojej biblioteki</p>
+                </div>
+            </div>
+            <button class="close-btn" @onclick="HandleClose" aria-label="Zamknij">
+                <NexusIcon Name="close" Size="20" />
+            </button>
+        </header>
+
+        <div class="sheet-body">
+            <div class="chat-thread" id="mobile-chat-thread">
+                @if (_chatMessages.Count == 0)
+                {
+                    <div class="welcome-container">
+                        <div class="welcome-glow-icon">
+                            <NexusIcon Name="brain" Size="32" Class="neon-glow" />
+                        </div>
+                        <h4>Zadaj pytanie asystentowi</h4>
+                        <p>KM-RAG przeszukuje całą treść książki, wyciąga semantyczne powiązania i generuje precyzyjne odpowiedzi wraz z przypisami źródłowymi.</p>
+                    </div>
+                }
+                else
+                {
+                    @foreach (var message in _chatMessages)
+                    {
+                        <div class="message-row @(message.Sender == "User" ? "user-row" : "ai-row")" @key="message.Id">
+                            <div class="message-avatar">
+                                @if (message.Sender == "User")
+                                {
+                                    <NexusIcon Name="user" Size="16" />
+                                }
+                                else
+                                {
+                                    <NexusIcon Name="robot" Size="16" />
+                                }
+                            </div>
+                            <div class="message-bubble @(message.Sender == "User" ? "user-bubble" : "ai-bubble")">
+                                <div class="message-meta">
+                                    <span class="sender-name">@(message.Sender == "User" ? "Ty" : "Asystent")</span>
+                                    <span class="message-time">@message.Timestamp.ToString("HH:mm")</span>
+                                </div>
+                                <div class="message-text">
+                                    @foreach (var segment in message.Segments)
+                                    {
+                                        @if (segment.IsCitation)
+                                        {
+                                            <span class="nexus-mobile-citation" @onclick="() => HandleCitationClick(segment.CitationId)">
+                                                [@segment.CitationId]
+                                            </span>
+                                        }
+                                        else
+                                        {
+                                            @RenderMarkdown(segment.Text)
+                                        }
+                                    }
+                                </div>
+                            </div>
+                        </div>
+                    }
+
+                    @if (_isLoading)
+                    {
+                        <div class="message-row ai-row">
+                            <div class="message-avatar">
+                                <NexusIcon Name="robot" Size="16" />
+                            </div>
+                            <div class="message-bubble ai-bubble pending-bubble">
+                                <div class="message-meta">
+                                    <span class="sender-name">Asystent</span>
+                                    <span class="message-time">Generowanie...</span>
+                                </div>
+                                <div class="message-text">
+                                    <div class="typing-indicator">
+                                        <span></span>
+                                        <span></span>
+                                        <span></span>
+                                    </div>
+                                    <span class="loading-label">Analiza grafu pojęć...</span>
+                                </div>
+                            </div>
+                        </div>
+                    }
+                }
+            </div>
+        </div>
+
+        <footer class="sheet-footer">
+            <div class="scope-indicator">
+                <NexusIcon Name="map" Size="12" />
+                <span>Obszar: <strong>@(string.IsNullOrEmpty(_activeBookTitle) ? "Cała biblioteka" : _activeBookTitle)</strong></span>
+            </div>
+            
+            <div class="input-container">
+                <input type="text" 
+                       class="nexus-mobile-input" 
+                       placeholder="Zadaj pytanie..." 
+                       @bind="_question" 
+                       @bind:event="oninput"
+                       @onkeyup="HandleKeyUp"
+                       disabled="@_isLoading" />
+                
+                <button class="send-btn @(string.IsNullOrWhiteSpace(_question) || _isLoading ? "disabled" : "")" 
+                        disabled="@(string.IsNullOrWhiteSpace(_question) || _isLoading)" 
+                        @onclick="AskQuestionAsync">
+                    @if (_isLoading)
+                    {
+                        <div class="btn-spinner"></div>
+                    }
+                    else
+                    {
+                        <NexusIcon Name="send" Size="18" />
+                    }
+                </button>
+            </div>
+        </footer>
+
+        @if (_selectedCitation != null)
+        {
+            <div class="citation-modal-overlay" @onclick="CloseCitationModal">
+                <div class="citation-modal glass-panel" @onclick:stopPropagation>
+                    <div class="modal-header">
+                        <span class="book-title"><NexusIcon Name="map" Size="14" /> @_selectedCitation.SourceBook</span>
+                        <button class="close-btn" @onclick="CloseCitationModal" aria-label="Close">
+                            <NexusIcon Name="close" Size="16" />
+                        </button>
+                    </div>
+                    <div class="modal-body">
+                        @if (!string.IsNullOrEmpty(_selectedCitation.Author))
+                        {
+                            <p class="citation-author"><strong>Autor:</strong> @_selectedCitation.Author</p>
+                        }
+                        @if (_selectedCitation.PageNumber.HasValue)
+                        {
+                            <p class="citation-page"><strong>Strona:</strong> @_selectedCitation.PageNumber.Value</p>
+                        }
+                        <p class="citation-snippet">"@_selectedCitation.Snippet"</p>
+                    </div>
+                    <div class="modal-footer">
+                        <button class="btn-nexus" @onclick="CloseCitationModal">Zamknij</button>
+                    </div>
+                </div>
+            </div>
+        }
+    </div>
+</div>
+
+@code {
+    [Parameter] public bool IsOpen { get; set; }
+    [Parameter] public EventCallback OnClose { get; set; }
+
+    private string _question = string.Empty;
+    private bool _isLoading;
+    private string _activeBookTitle = string.Empty;
+    private List<ChatMessage> _chatMessages = new();
+    private CitationDto? _selectedCitation;
+
+    protected override async Task OnParametersSetAsync()
+    {
+        if (IsOpen && string.IsNullOrEmpty(_activeBookTitle) && NavigationService.CurrentEbookId != Guid.Empty)
+        {
+            _activeBookTitle = NavigationService.ChapterTitle ?? "Aktywna książka";
+        }
+    }
+
+    private async Task HandleClose()
+    {
+        if (OnClose.HasDelegate)
+        {
+            await OnClose.InvokeAsync();
+        }
+    }
+
+    private async Task HandleKeyUp(KeyboardEventArgs e)
+    {
+        if (e.Key == "Enter" && !string.IsNullOrWhiteSpace(_question) && !_isLoading)
+        {
+            await AskQuestionAsync();
+        }
+    }
+
+    private void HandleCitationClick(string citationId)
+    {
+        _selectedCitation = _chatMessages
+            .SelectMany(m => m.Citations)
+            .FirstOrDefault(c => c.CitationId.Equals(citationId, StringComparison.OrdinalIgnoreCase))
+            ?? new CitationDto
+            {
+                CitationId = citationId,
+                SourceBook = "Grounded Document Chunk",
+                Snippet = "Context snippet retrieved from vector search node."
+            };
+    }
+
+    private void CloseCitationModal()
+    {
+        _selectedCitation = null;
+    }
+
+    private async Task AskQuestionAsync()
+    {
+        if (string.IsNullOrWhiteSpace(_question) || _isLoading) return;
+
+        var userQuestion = _question;
+        _question = string.Empty;
+        _isLoading = true;
+
+        _chatMessages.Add(new ChatMessage
+        {
+            Sender = "User",
+            Text = userQuestion,
+            Segments = new List<ResponseSegment> { new ResponseSegment { Text = userQuestion, IsCitation = false } }
+        });
+
+        StateHasChanged();
+
+        try
+        {
+            Guid? ebookId = null;
+            if (NavigationService.CurrentEbookId != Guid.Empty)
+            {
+                ebookId = NavigationService.CurrentEbookId;
+            }
+
+            var authState = await AuthStateProvider.GetAuthenticationStateAsync();
+            var tenantId = authState.User.FindFirst("TenantId")?.Value ?? "global";
+
+            var result = await KnowledgeService.AskQuestionAsync(userQuestion, tenantId, ebookId);
+            if (result.IsSuccess)
+            {
+                var response = result.Value;
+                _chatMessages.Add(new ChatMessage
+                {
+                    Sender = "AI",
+                    Text = response.Answer,
+                    Segments = ParseSegments(response.Answer),
+                    Citations = response.Citations
+                });
+            }
+            else
+            {
+                var errMsg = $"Błąd: {result.Errors.FirstOrDefault()?.Message ?? "Wystąpił nieznany problem."}";
+                _chatMessages.Add(new ChatMessage
+                {
+                    Sender = "AI",
+                    Text = errMsg,
+                    Segments = new List<ResponseSegment> { new ResponseSegment { Text = errMsg, IsCitation = false } }
+                });
+            }
+        }
+        catch (Exception ex)
+        {
+            var errMsg = $"Błąd sieci/API: {ex.Message}";
+            _chatMessages.Add(new ChatMessage
+            {
+                Sender = "AI",
+                Text = errMsg,
+                Segments = new List<ResponseSegment> { new ResponseSegment { Text = errMsg, IsCitation = false } }
+            });
+        }
+        finally
+        {
+            _isLoading = false;
+            StateHasChanged();
+        }
+    }
+
+    private List<ResponseSegment> ParseSegments(string text)
+    {
+        var segments = new List<ResponseSegment>();
+        if (string.IsNullOrEmpty(text)) return segments;
+
+        var regex = new System.Text.RegularExpressions.Regex(
+            @"\[Source ID:\s*([^\]]+)\]|\[([a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12})\]", 
+            System.Text.RegularExpressions.RegexOptions.IgnoreCase);
+        var matches = regex.Matches(text);
+
+        int lastIndex = 0;
+        foreach (System.Text.RegularExpressions.Match match in matches)
+        {
+            if (match.Index > lastIndex)
+            {
+                segments.Add(new ResponseSegment
+                {
+                    Text = text.Substring(lastIndex, match.Index - lastIndex),
+                    IsCitation = false
+                });
+            }
+
+            var citationId = match.Groups[1].Success 
+                ? match.Groups[1].Value.Trim() 
+                : match.Groups[2].Value.Trim();
+
+            segments.Add(new ResponseSegment
+            {
+                IsCitation = true,
+                CitationId = citationId
+            });
+
+            lastIndex = match.Index + match.Length;
+        }
+
+        if (lastIndex < text.Length)
+        {
+            segments.Add(new ResponseSegment
+            {
+                Text = text.Substring(lastIndex),
+                IsCitation = false
+            });
+        }
+
+        return segments;
+    }
+
+    private MarkupString RenderMarkdown(string text)
+    {
+        if (string.IsNullOrEmpty(text)) return new MarkupString(string.Empty);
+
+        var html = System.Net.WebUtility.HtmlEncode(text);
+        html = System.Text.RegularExpressions.Regex.Replace(html, @"\*\*(.*?)\*\*", "<strong>$1</strong>");
+        html = System.Text.RegularExpressions.Regex.Replace(html, @"\*(.*?)\*", "<em>$1</em>");
+        html = System.Text.RegularExpressions.Regex.Replace(html, @"```(?:[a-zA-Z0-9+#]+)?\s*([\s\S]*?)\s*```", "<pre class=\"nexus-mobile-code-block\"><code>$1</code></pre>");
+        html = System.Text.RegularExpressions.Regex.Replace(html, @"`(.*?)`", "<code class=\"nexus-mobile-inline-code\">$1</code>");
+        html = html.Replace("\n", "<br />");
+
+        return new MarkupString(html);
+    }
+}

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

@@ -0,0 +1,545 @@
+.global-intelligence-sheet {
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100vw;
+    height: 100vh;
+    z-index: 1500;
+    display: flex;
+    flex-direction: column;
+    justify-content: flex-end;
+    pointer-events: none;
+    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
+}
+
+.global-intelligence-sheet.is-open {
+    pointer-events: all;
+}
+
+.sheet-backdrop {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    background-color: rgba(0, 0, 0, 0.4);
+    backdrop-filter: blur(4px);
+    opacity: 0;
+    transition: opacity 0.35s ease;
+    z-index: 1;
+}
+
+.global-intelligence-sheet.is-open .sheet-backdrop {
+    opacity: 1;
+}
+
+.sheet-content {
+    position: relative;
+    width: 100%;
+    height: 80vh;
+    background: rgba(18, 18, 18, 0.85);
+    backdrop-filter: blur(24px);
+    border-top: 1px solid rgba(0, 255, 153, 0.3);
+    border-top-left-radius: 20px;
+    border-top-right-radius: 20px;
+    box-shadow: 0 -10px 40px rgba(0, 0, 0, 0.5);
+    z-index: 2;
+    transform: translateY(100%);
+    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
+    display: flex;
+    flex-direction: column;
+}
+
+.global-intelligence-sheet.is-open .sheet-content {
+    transform: translateY(0);
+}
+
+.sheet-drag-handle {
+    width: 40px;
+    height: 4px;
+    background-color: rgba(255, 255, 255, 0.2);
+    border-radius: 2px;
+    margin: 10px auto 4px auto;
+}
+
+.sheet-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 0.75rem 1.25rem;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
+}
+
+.header-main {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+}
+
+.ai-avatar-badge {
+    width: 36px;
+    height: 36px;
+    border-radius: 10px;
+    background: linear-gradient(135deg, rgba(0, 255, 153, 0.15) 0%, rgba(0, 240, 255, 0.15) 100%);
+    border: 1px solid rgba(0, 255, 153, 0.3);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.ai-avatar-badge ::deep i {
+    color: var(--nexus-neon, #00FF99);
+}
+
+.header-info h3 {
+    font-size: 1rem;
+    font-weight: 600;
+    color: #FFFFFF;
+    margin: 0;
+}
+
+.header-info .subtitle {
+    font-size: 0.75rem;
+    color: rgba(255, 255, 255, 0.5);
+    margin: 0;
+}
+
+.close-btn {
+    background: none;
+    border: none;
+    color: rgba(255, 255, 255, 0.6);
+    padding: 6px;
+    border-radius: 50%;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: all 0.2s ease;
+}
+
+.close-btn:hover {
+    background-color: rgba(255, 255, 255, 0.05);
+    color: #FFFFFF;
+}
+
+.sheet-body {
+    flex: 1;
+    overflow-y: auto;
+    padding: 1.25rem;
+}
+
+.chat-thread {
+    display: flex;
+    flex-direction: column;
+    gap: 1.25rem;
+    padding-bottom: 2rem;
+}
+
+.welcome-container {
+    text-align: center;
+    padding: 4rem 1.5rem;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+}
+
+.welcome-glow-icon {
+    width: 64px;
+    height: 64px;
+    border-radius: 50%;
+    background: rgba(0, 255, 153, 0.05);
+    border: 1px solid rgba(0, 255, 153, 0.15);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    margin-bottom: 1.25rem;
+    box-shadow: 0 0 20px rgba(0, 255, 153, 0.1);
+}
+
+.welcome-glow-icon ::deep i {
+    color: var(--nexus-neon, #00FF99);
+}
+
+.welcome-container h4 {
+    font-size: 1.1rem;
+    font-weight: 550;
+    color: #FFFFFF;
+    margin-bottom: 0.5rem;
+}
+
+.welcome-container p {
+    font-size: 0.85rem;
+    color: rgba(255, 255, 255, 0.55);
+    line-height: 1.5;
+    max-width: 280px;
+}
+
+.message-row {
+    display: flex;
+    gap: 0.75rem;
+    max-width: 88%;
+}
+
+.message-row.user-row {
+    align-self: flex-end;
+    flex-direction: row-reverse;
+}
+
+.message-row.ai-row {
+    align-self: flex-start;
+}
+
+.message-avatar {
+    width: 28px;
+    height: 28px;
+    border-radius: 50%;
+    background-color: rgba(255, 255, 255, 0.05);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    flex-shrink: 0;
+}
+
+.user-row .message-avatar {
+    background-color: rgba(0, 255, 153, 0.1);
+    border: 1px solid rgba(0, 255, 153, 0.2);
+}
+
+.message-avatar ::deep i {
+    font-size: 0.85rem;
+    color: rgba(255, 255, 255, 0.7);
+}
+
+.user-row .message-avatar ::deep i {
+    color: var(--nexus-neon, #00FF99);
+}
+
+.message-bubble {
+    padding: 0.75rem 1rem;
+    border-radius: 14px;
+    position: relative;
+}
+
+.user-bubble {
+    background-color: rgba(0, 255, 153, 0.08);
+    border: 1px solid rgba(0, 255, 153, 0.2);
+    border-top-right-radius: 2px;
+}
+
+.ai-bubble {
+    background-color: rgba(255, 255, 255, 0.03);
+    border: 1px solid rgba(255, 255, 255, 0.06);
+    border-top-left-radius: 2px;
+}
+
+.message-meta {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    margin-bottom: 0.25rem;
+    gap: 1rem;
+}
+
+.sender-name {
+    font-size: 0.7rem;
+    font-weight: 600;
+    text-transform: uppercase;
+    letter-spacing: 0.05em;
+}
+
+.user-bubble .sender-name {
+    color: var(--nexus-neon, #00FF99);
+}
+
+.ai-bubble .sender-name {
+    color: rgba(255, 255, 255, 0.7);
+}
+
+.message-time {
+    font-size: 0.65rem;
+    color: rgba(255, 255, 255, 0.4);
+}
+
+.message-text {
+    font-size: 0.85rem;
+    line-height: 1.5;
+    color: rgba(255, 255, 255, 0.9);
+}
+
+.message-text strong {
+    color: #FFFFFF;
+}
+
+.nexus-mobile-citation {
+    background-color: rgba(0, 240, 255, 0.15);
+    border: 1px solid rgba(0, 240, 255, 0.3);
+    color: #00F0FF;
+    border-radius: 4px;
+    padding: 1px 4px;
+    font-size: 0.75rem;
+    font-weight: bold;
+    cursor: pointer;
+    margin-left: 2px;
+    display: inline-block;
+}
+
+.nexus-mobile-code-block {
+    background-color: rgba(0, 0, 0, 0.4);
+    border-left: 3px solid var(--nexus-neon, #00FF99);
+    padding: 0.75rem;
+    border-radius: 6px;
+    margin: 0.5rem 0;
+    overflow-x: auto;
+    font-family: monospace;
+    font-size: 0.75rem;
+}
+
+.nexus-mobile-inline-code {
+    background-color: rgba(255, 255, 255, 0.08);
+    color: #FF7B72;
+    padding: 2px 4px;
+    border-radius: 4px;
+    font-family: monospace;
+    font-size: 0.75rem;
+}
+
+/* Typing indicator */
+.typing-indicator {
+    display: inline-flex;
+    align-items: center;
+    gap: 4px;
+    padding: 4px 0;
+}
+
+.typing-indicator span {
+    width: 6px;
+    height: 6px;
+    background-color: rgba(255, 255, 255, 0.5);
+    border-radius: 50%;
+    animation: bounce 1.4s infinite ease-in-out both;
+}
+
+.typing-indicator span:nth-child(1) { animation-delay: -0.32s; }
+.typing-indicator span:nth-child(2) { animation-delay: -0.16s; }
+
+@keyframes bounce {
+    0%, 80%, 100% { transform: scale(0); }
+    40% { transform: scale(1); }
+}
+
+.loading-label {
+    font-size: 0.75rem;
+    color: rgba(255, 255, 255, 0.5);
+    margin-left: 8px;
+    vertical-align: middle;
+}
+
+.sheet-footer {
+    padding: 0.75rem 1rem 1.5rem 1rem;
+    border-top: 1px solid rgba(255, 255, 255, 0.08);
+    background-color: rgba(10, 10, 10, 0.5);
+}
+
+.scope-indicator {
+    display: flex;
+    align-items: center;
+    gap: 4px;
+    font-size: 0.7rem;
+    color: rgba(255, 255, 255, 0.45);
+    margin-bottom: 0.5rem;
+}
+
+.scope-indicator ::deep i {
+    color: rgba(255, 255, 255, 0.4);
+}
+
+.input-container {
+    display: flex;
+    gap: 0.5rem;
+    align-items: center;
+}
+
+.nexus-mobile-input {
+    flex: 1;
+    background-color: rgba(255, 255, 255, 0.04);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    border-radius: 12px;
+    padding: 0.65rem 0.9rem;
+    font-size: 0.85rem;
+    color: #FFFFFF;
+    outline: none;
+    transition: all 0.25s ease;
+}
+
+.nexus-mobile-input:focus {
+    border-color: rgba(0, 255, 153, 0.4);
+    background-color: rgba(255, 255, 255, 0.07);
+    box-shadow: 0 0 8px rgba(0, 255, 153, 0.15);
+}
+
+.send-btn {
+    width: 38px;
+    height: 38px;
+    border-radius: 12px;
+    background: linear-gradient(135deg, #00FF99 0%, #00F0FF 100%);
+    border: none;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    color: #0b0c10;
+    cursor: pointer;
+    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
+    box-shadow: 0 0 10px rgba(0, 255, 153, 0.2);
+    flex-shrink: 0;
+}
+
+.send-btn.disabled {
+    background: rgba(255, 255, 255, 0.05);
+    color: rgba(255, 255, 255, 0.3);
+    box-shadow: none;
+    cursor: not-allowed;
+}
+
+.btn-spinner {
+    width: 16px;
+    height: 16px;
+    border: 2px solid rgba(0,0,0,0.1);
+    border-top: 2px solid #000000;
+    border-radius: 50%;
+    animation: spin 1s linear infinite;
+}
+
+@keyframes spin {
+    0% { transform: rotate(0deg); }
+    100% { transform: rotate(360deg); }
+}
+
+/* Citation Modal Overlay & Glassmorphic Card */
+.citation-modal-overlay {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    background-color: rgba(0, 0, 0, 0.6);
+    backdrop-filter: blur(8px);
+    z-index: 10;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    padding: 1.5rem;
+    animation: fadeIn 0.25s ease-out;
+}
+
+.citation-modal {
+    width: 100%;
+    max-width: 320px;
+    background: rgba(20, 20, 20, 0.85);
+    border: 1px solid rgba(0, 240, 255, 0.25);
+    box-shadow: 0 0 30px rgba(0, 240, 255, 0.15);
+    border-radius: 16px;
+    display: flex;
+    flex-direction: column;
+    overflow: hidden;
+    animation: slideUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
+}
+
+.citation-modal .modal-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 0.75rem 1rem;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
+}
+
+.citation-modal .book-title {
+    font-size: 0.85rem;
+    font-weight: 600;
+    color: #FFFFFF;
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+}
+
+.citation-modal .book-title ::deep i {
+    color: #00F0FF;
+}
+
+.citation-modal .close-btn {
+    background: none;
+    border: none;
+    color: rgba(255, 255, 255, 0.5);
+    cursor: pointer;
+    padding: 4px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.citation-modal .modal-body {
+    padding: 1rem;
+    font-size: 0.8rem;
+    line-height: 1.5;
+    color: rgba(255, 255, 255, 0.85);
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+}
+
+.citation-modal .citation-author,
+.citation-modal .citation-page {
+    font-size: 0.75rem;
+    color: rgba(255, 255, 255, 0.5);
+    margin: 0;
+}
+
+.citation-modal .citation-author strong,
+.citation-modal .citation-page strong {
+    color: rgba(255, 255, 255, 0.75);
+}
+
+.citation-modal .citation-snippet {
+    font-style: italic;
+    background: rgba(0, 240, 255, 0.04);
+    border-left: 2px solid #00F0FF;
+    padding: 0.5rem 0.75rem;
+    border-radius: 4px;
+    color: rgba(255, 255, 255, 0.9);
+    margin: 0.25rem 0 0 0;
+}
+
+.citation-modal .modal-footer {
+    display: flex;
+    justify-content: flex-end;
+    padding: 0.75rem 1rem;
+    border-top: 1px solid rgba(255, 255, 255, 0.08);
+}
+
+.citation-modal .btn-nexus {
+    font-size: 0.8rem;
+    padding: 0.4rem 1rem;
+    border-radius: 8px;
+    background: linear-gradient(135deg, rgba(0, 240, 255, 0.2) 0%, rgba(0, 255, 153, 0.2) 100%);
+    border: 1px solid rgba(0, 240, 255, 0.4);
+    color: #FFFFFF;
+    font-weight: 550;
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.citation-modal .btn-nexus:hover {
+    background: linear-gradient(135deg, rgba(0, 240, 255, 0.35) 0%, rgba(0, 255, 153, 0.35) 100%);
+    border-color: rgba(0, 240, 255, 0.6);
+    box-shadow: 0 0 10px rgba(0, 240, 255, 0.2);
+}
+
+@keyframes fadeIn {
+    from { opacity: 0; }
+    to { opacity: 1; }
+}
+
+@keyframes slideUp {
+    from { transform: translateY(20px); opacity: 0; }
+    to { transform: translateY(0); opacity: 1; }
+}

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

@@ -0,0 +1,151 @@
+@using NexusReader.UI.Shared.Components.Atoms
+@using NexusReader.UI.Shared.Services
+@using NexusReader.UI.Shared.Models
+@using NexusReader.Application.Utilities
+@namespace NexusReader.UI.Shared.Components.Organisms
+@inject IReaderInteractionService InteractionService
+@inject IReaderStateService StateService
+
+<div class="nexus-unified-mobile-toolbar">
+    <!-- LEFT SLOT: Progress & Section Checkpoints -->
+    <div class="toolbar-slot left-slot" @onclick="ToggleCheckpoints" title="Rozdziały i checkpoints">
+        <div class="progress-ring-wrapper">
+            <svg class="progress-ring" width="38" height="38">
+                <circle class="progress-ring-track" stroke="rgba(255,255,255,0.06)" stroke-width="2.5" fill="transparent" r="16" cx="19" cy="19" />
+                <circle class="progress-ring-indicator" stroke="var(--nexus-neon, #00FF99)" stroke-width="2.5" fill="transparent" r="16" cx="19" cy="19"
+                        stroke-dasharray="100.53" stroke-dashoffset="@GetDashOffset()" />
+            </svg>
+            <span class="progress-text">@ScrollPercentage%</span>
+        </div>
+        <div class="progress-info">
+            <span class="slot-label">Postęp</span>
+            <span class="slot-desc">Checkpoints</span>
+        </div>
+    </div>
+
+    <!-- CENTER SLOT: Global AI Assistant Glowing Trigger -->
+    <div class="toolbar-slot center-slot">
+        <button class="btn-nexus-ai-core" @onclick="HandleAssistantClick" aria-label="Asystent AI">
+            <div class="pulse-ring"></div>
+            <div class="pulse-ring-outer"></div>
+            <NexusIcon Name="robot" Size="22" Class="ai-core-icon" />
+        </button>
+    </div>
+
+    <!-- RIGHT SLOT: Context View Toggles -->
+    <div class="toolbar-slot right-slot">
+        <button class="nav-toggle-btn @(ActiveTab == MobileReaderTab.Reader ? "active" : "")" 
+                @onclick="() => ChangeTab(MobileReaderTab.Reader)" 
+                aria-label="Tekst">
+            <NexusIcon Name="book-open" Size="18" />
+            <span>Tekst</span>
+        </button>
+        <button class="nav-toggle-btn @(ActiveTab == MobileReaderTab.Graph ? "active" : "")" 
+                @onclick="() => ChangeTab(MobileReaderTab.Graph)" 
+                aria-label="Graf">
+            <NexusIcon Name="share-2" Size="18" />
+            <span>Graf</span>
+        </button>
+        <button class="nav-toggle-btn @(ActiveTab == MobileReaderTab.Concepts ? "active" : "")" 
+                @onclick="() => ChangeTab(MobileReaderTab.Concepts)" 
+                aria-label="Mapa">
+            <NexusIcon Name="map" Size="18" />
+            <span>Mapa</span>
+        </button>
+    </div>
+</div>
+
+<!-- SECTION CHECKPOINTS OVERLAY -->
+<div class="checkpoints-overlay @(IsCheckpointsOpen ? "is-open" : "")">
+    <div class="checkpoints-backdrop" @onclick="ToggleCheckpoints"></div>
+    <div class="checkpoints-sheet">
+        <div class="sheet-drag-handle"></div>
+        <header class="checkpoints-header">
+            <h4>Checkpoints Sekcji</h4>
+            <button class="close-checkpoints-btn" @onclick="ToggleCheckpoints">
+                <NexusIcon Name="close" Size="16" />
+            </button>
+        </header>
+        <div class="checkpoints-body">
+            @if (Checkpoints == null || !Checkpoints.Any())
+            {
+                <div class="empty-checkpoints">
+                    <NexusIcon Name="info" Size="20" />
+                    <p>Brak punktów kontrolnych w tym rozdziale.</p>
+                </div>
+            }
+            else
+            {
+                <div class="checkpoints-list">
+                    @foreach (var cp in Checkpoints)
+                    {
+                        var isCurrent = cp == StateService.CurrentBlockId;
+                        <div class="checkpoint-item @(isCurrent ? "active" : "")" @onclick="() => SelectCheckpoint(cp)">
+                            <div class="checkpoint-indicator">
+                                <div class="indicator-dot"></div>
+                                <div class="indicator-line"></div>
+                            </div>
+                            <div class="checkpoint-details">
+                                <span class="checkpoint-id">@cp.ToUpper()</span>
+                                <span class="checkpoint-label">@(isCurrent ? "Aktualna sekcja" : "Przejdź do sekcji")</span>
+                            </div>
+                            <NexusIcon Name="chevron-right" Size="14" Class="arrow-icon" />
+                        </div>
+                    }
+                </div>
+            }
+        </div>
+    </div>
+</div>
+
+@code {
+    [Parameter] public int ScrollPercentage { get; set; }
+    [Parameter] public MobileReaderTab ActiveTab { get; set; }
+    [Parameter] public EventCallback<MobileReaderTab> OnTabChanged { get; set; }
+    [Parameter] public EventCallback OnAssistantClick { get; set; }
+    [Parameter] public List<string> Checkpoints { get; set; } = new();
+
+    private bool IsCheckpointsOpen { get; set; }
+
+
+    private double GetDashOffset()
+    {
+        // Circumference of r=16 is 2 * pi * 16 = 100.53
+        double circumference = 100.53;
+        double progress = Math.Clamp(ScrollPercentage, 0, 100);
+        return circumference - (progress / 100.0) * circumference;
+    }
+
+    private void ToggleCheckpoints()
+    {
+        IsCheckpointsOpen = !IsCheckpointsOpen;
+    }
+
+    private async Task SelectCheckpoint(string checkpointId)
+    {
+        IsCheckpointsOpen = false;
+        // Scroll to the targeted block
+        await InteractionService.RequestScrollToBlock(checkpointId);
+        // Ensure user is on the text reading tab to see the scroll happen
+        if (ActiveTab != MobileReaderTab.Reader)
+        {
+            await ChangeTab(MobileReaderTab.Reader);
+        }
+    }
+
+    private async Task ChangeTab(MobileReaderTab tab)
+    {
+        if (OnTabChanged.HasDelegate)
+        {
+            await OnTabChanged.InvokeAsync(tab);
+        }
+    }
+
+    private async Task HandleAssistantClick()
+    {
+        if (OnAssistantClick.HasDelegate)
+        {
+            await OnAssistantClick.InvokeAsync();
+        }
+    }
+}

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

@@ -0,0 +1,362 @@
+.nexus-unified-mobile-toolbar {
+    position: fixed;
+    bottom: 16px;
+    left: 16px;
+    right: 16px;
+    height: 64px;
+    background: rgba(18, 18, 18, 0.75);
+    backdrop-filter: blur(24px);
+    -webkit-backdrop-filter: blur(24px);
+    border: 1px solid rgba(0, 255, 153, 0.2);
+    border-radius: 16px;
+    display: grid;
+    grid-template-columns: 1fr auto 1fr;
+    align-items: center;
+    padding: 0 1rem;
+    z-index: 1000;
+    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
+    box-sizing: border-box;
+    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
+}
+
+.toolbar-slot {
+    display: flex;
+    align-items: center;
+}
+
+/* LEFT SLOT: Progress circular ring */
+.left-slot {
+    justify-content: flex-start;
+    gap: 0.65rem;
+    cursor: pointer;
+    user-select: none;
+}
+
+.progress-ring-wrapper {
+    position: relative;
+    width: 38px;
+    height: 38px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.progress-ring {
+    transform: rotate(-90deg);
+}
+
+.progress-ring-indicator {
+    transition: stroke-dashoffset 0.35s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.progress-text {
+    position: absolute;
+    font-size: 0.65rem;
+    font-weight: 700;
+    color: #FFFFFF;
+}
+
+.progress-info {
+    display: flex;
+    flex-direction: column;
+}
+
+.slot-label {
+    font-size: 0.75rem;
+    font-weight: 600;
+    color: #FFFFFF;
+}
+
+.slot-desc {
+    font-size: 0.6rem;
+    color: rgba(255,255,255,0.4);
+}
+
+/* CENTER SLOT: Glowing AI Core Button */
+.center-slot {
+    justify-content: center;
+    position: relative;
+}
+
+.btn-nexus-ai-core {
+    width: 52px;
+    height: 52px;
+    border-radius: 50%;
+    background: linear-gradient(135deg, #00FF99 0%, #00F0FF 100%);
+    border: none;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    color: #0B0C10;
+    cursor: pointer;
+    position: relative;
+    z-index: 5;
+    box-shadow: 0 0 20px rgba(0, 255, 153, 0.4);
+    transform: translateY(-8px);
+    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
+}
+
+.btn-nexus-ai-core:active {
+    transform: translateY(-6px) scale(0.95);
+    box-shadow: 0 0 10px rgba(0, 255, 153, 0.3);
+}
+
+.ai-core-icon {
+    color: #0b0c10;
+    filter: drop-shadow(0 1px 2px rgba(0,0,0,0.2));
+}
+
+/* Pulse effects */
+.pulse-ring {
+    position: absolute;
+    top: -4px;
+    left: -4px;
+    right: -4px;
+    bottom: -4px;
+    border-radius: 50%;
+    border: 2px solid rgba(0, 255, 153, 0.4);
+    opacity: 0;
+    animation: corePulse 2s cubic-bezier(0.24, 0, 0.38, 1) infinite;
+    pointer-events: none;
+    z-index: 1;
+}
+
+.pulse-ring-outer {
+    position: absolute;
+    top: -8px;
+    left: -8px;
+    right: -8px;
+    bottom: -8px;
+    border-radius: 50%;
+    border: 1px solid rgba(0, 240, 255, 0.2);
+    opacity: 0;
+    animation: corePulseOuter 2.5s cubic-bezier(0.24, 0, 0.38, 1) infinite;
+    pointer-events: none;
+    z-index: 1;
+}
+
+@keyframes corePulse {
+    0% { transform: scale(0.95); opacity: 0; }
+    50% { opacity: 0.8; }
+    100% { transform: scale(1.15); opacity: 0; }
+}
+
+@keyframes corePulseOuter {
+    0% { transform: scale(0.9); opacity: 0; }
+    50% { opacity: 0.5; }
+    100% { transform: scale(1.25); opacity: 0; }
+}
+
+/* RIGHT SLOT: Layout Switching */
+.right-slot {
+    justify-content: flex-end;
+    gap: 0.35rem;
+}
+
+.nav-toggle-btn {
+    background: none;
+    border: none;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 2px;
+    padding: 6px 8px;
+    border-radius: 8px;
+    color: rgba(255, 255, 255, 0.45);
+    cursor: pointer;
+    transition: all 0.25s ease;
+}
+
+.nav-toggle-btn.active {
+    color: var(--nexus-neon, #00FF99);
+    background-color: rgba(0, 255, 153, 0.06);
+}
+
+.nav-toggle-btn ::deep .nexus-icon {
+    transition: transform 0.2s ease;
+}
+
+.nav-toggle-btn.active ::deep .nexus-icon {
+    transform: scale(1.08);
+}
+
+.nav-toggle-btn span {
+    font-size: 0.6rem;
+    font-weight: 500;
+}
+
+/* SECTION CHECKPOINTS OVERLAY */
+.checkpoints-overlay {
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100vw;
+    height: 100vh;
+    z-index: 1400;
+    display: flex;
+    flex-direction: column;
+    justify-content: flex-end;
+    pointer-events: none;
+}
+
+.checkpoints-overlay.is-open {
+    pointer-events: all;
+}
+
+.checkpoints-backdrop {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    background-color: rgba(0, 0, 0, 0.3);
+    backdrop-filter: blur(3px);
+    opacity: 0;
+    transition: opacity 0.3s ease;
+    z-index: 1;
+}
+
+.checkpoints-overlay.is-open .checkpoints-backdrop {
+    opacity: 1;
+}
+
+.checkpoints-sheet {
+    position: relative;
+    width: 100%;
+    max-height: 50vh;
+    background: rgba(15, 15, 15, 0.9);
+    backdrop-filter: blur(20px);
+    border-top: 1px solid rgba(255, 255, 255, 0.08);
+    border-top-left-radius: 16px;
+    border-top-right-radius: 16px;
+    box-shadow: 0 -8px 30px rgba(0, 0, 0, 0.5);
+    z-index: 2;
+    transform: translateY(100%);
+    transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
+    display: flex;
+    flex-direction: column;
+}
+
+.checkpoints-overlay.is-open .checkpoints-sheet {
+    transform: translateY(0);
+}
+
+.checkpoints-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    padding: 0.75rem 1.25rem;
+    border-bottom: 1px solid rgba(255,255,255,0.06);
+}
+
+.checkpoints-header h4 {
+    font-size: 0.9rem;
+    font-weight: 600;
+    color: #FFFFFF;
+    margin: 0;
+}
+
+.close-checkpoints-btn {
+    background: none;
+    border: none;
+    color: rgba(255,255,255,0.5);
+    padding: 4px;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+}
+
+.checkpoints-body {
+    flex: 1;
+    overflow-y: auto;
+    padding: 1rem 1.25rem;
+}
+
+.empty-checkpoints {
+    text-align: center;
+    padding: 2rem 1rem;
+    color: rgba(255,255,255,0.4);
+}
+
+.empty-checkpoints p {
+    font-size: 0.8rem;
+    margin-top: 0.5rem;
+}
+
+.checkpoints-list {
+    display: flex;
+    flex-direction: column;
+    gap: 0.5rem;
+    padding-bottom: 1rem;
+}
+
+.checkpoint-item {
+    display: flex;
+    align-items: center;
+    padding: 0.75rem;
+    border-radius: 10px;
+    background-color: rgba(255,255,255,0.02);
+    border: 1px solid rgba(255,255,255,0.04);
+    cursor: pointer;
+    transition: all 0.2s ease;
+}
+
+.checkpoint-item:active {
+    background-color: rgba(255,255,255,0.05);
+}
+
+.checkpoint-item.active {
+    background-color: rgba(0, 255, 153, 0.04);
+    border-color: rgba(0, 255, 153, 0.15);
+}
+
+.checkpoint-indicator {
+    width: 14px;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    margin-right: 0.75rem;
+}
+
+.indicator-dot {
+    width: 6px;
+    height: 6px;
+    border-radius: 50%;
+    background-color: rgba(255,255,255,0.3);
+}
+
+.checkpoint-item.active .indicator-dot {
+    background-color: var(--nexus-neon, #00FF99);
+    box-shadow: 0 0 8px rgba(0, 255, 153, 0.6);
+}
+
+.checkpoint-details {
+    flex: 1;
+    display: flex;
+    flex-direction: column;
+}
+
+.checkpoint-id {
+    font-size: 0.8rem;
+    font-weight: 700;
+    color: #FFFFFF;
+}
+
+.checkpoint-item.active .checkpoint-id {
+    color: var(--nexus-neon, #00FF99);
+}
+
+.checkpoint-label {
+    font-size: 0.65rem;
+    color: rgba(255,255,255,0.4);
+    margin-top: 1px;
+}
+
+.arrow-icon {
+    color: rgba(255,255,255,0.25);
+    transition: transform 0.2s ease;
+}
+
+.checkpoint-item:active .arrow-icon {
+    transform: translateX(2px);
+}

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

@@ -2,8 +2,9 @@
 @using NexusReader.Application.Queries.Reader
 @using Microsoft.JSInterop
 @using NexusReader.UI.Shared.Services
+@using NexusReader.UI.Shared.Models
 @using Microsoft.AspNetCore.Components.Authorization
-@implements IDisposable
+@implements IAsyncDisposable
 @inject IMediator Mediator
 @inject IJSRuntime JS
 @inject IThemeService ThemeService
@@ -11,13 +12,36 @@
 @inject IReaderNavigationService NavigationService
 @inject KnowledgeCoordinator Coordinator
 @inject IReaderInteractionService InteractionService
+@inject IReaderStateService StateService
 @inject ISyncService SyncService
 @inject AuthenticationStateProvider AuthStateProvider
 @inject IQuizStateService QuizService
 @inject IPlatformService PlatformService
+@inject NavigationManager Navigation
 @inject ILogger<ReaderCanvas> Logger
 
 <div class="reader-canvas @(ThemeService.IsLightMode ? "theme-light" : "theme-dark")">
+    @if (_isMobile && ViewModel != null)
+    {
+        <header class="nexus-mobile-reader-header">
+            <button class="nexus-mobile-escape-btn" @onclick="HandleEscape" aria-label="Powrót do pulpitu">
+                <NexusIcon Name="chevron-left" Size="18" />
+                <span>Pulpit</span>
+            </button>
+            <div class="nexus-mobile-chapter-navigation">
+                <button class="nexus-chapter-nav-btn prev" @onclick="NavigationService.GoToPreviousChapter" disabled="@(NavigationService.CurrentChapterIndex == 0)" aria-label="Poprzedni rozdział">
+                    <NexusIcon Name="chevron-left" Size="14" />
+                </button>
+                <div class="nexus-mobile-chapter-title">
+                    @ViewModel.ChapterTitle
+                </div>
+                <button class="nexus-chapter-nav-btn next" @onclick="NavigationService.GoToNextChapter" disabled="@(NavigationService.CurrentChapterIndex >= NavigationService.TotalChapters - 1)" aria-label="Następny rozdział">
+                    <NexusIcon Name="chevron-right" Size="14" />
+                </button>
+            </div>
+        </header>
+    }
+
     @if (ViewModel == null)
     {
         <div class="loading-state full-page">
@@ -56,16 +80,7 @@
         Coordinates="@_selectionCoords"
         FullPageContent="@GetFullPageContent()" />
 
-    @if (_isMobile)
+
-    {
-        <button class="nexus-mobile-assistant-fab @(QuizService.HasNewQuiz ? "has-new-quiz" : "")" @onclick="HandleAssistantFabClick" aria-label="Asystent AI">
-            <NexusIcon Name="robot" Size="24" Class="neon-glow" />
-            @if (QuizService.HasNewQuiz)
-            {
-                <span class="fab-badge"></span>
-            }
-        </button>
-    }
 </div>
 
 @code {
@@ -83,6 +98,7 @@
     private string? _currentActiveBlockId;
     private bool _isMobile = false;
     private DotNetObjectReference<ReaderCanvas>? _selfReference;
+    private IJSObjectReference? _viewportModule;
 
     protected override async Task OnInitializedAsync()
     {
@@ -147,23 +163,11 @@
     {
         try
         {
+            _viewportModule = await JS.InvokeAsync<IJSObjectReference>("import", "./_content/NexusReader.UI.Shared/js/viewport.js");
             _selfReference = DotNetObjectReference.Create(this);
-            var isMobileViewport = await JS.InvokeAsync<bool>("eval", "window.innerWidth < 768");
+            var isMobileViewport = await _viewportModule.InvokeAsync<bool>("isMobileViewport");
             await OnViewportChanged(isMobileViewport);
-
+            await _viewportModule.InvokeVoidAsync("registerViewportObserver", _selfReference);
-            await JS.InvokeVoidAsync("eval", @"
-                window.registerCanvasViewportObserver = (dotNetHelper) => {
-                    let currentIsMobile = window.innerWidth < 768;
-                    window.addEventListener('resize', () => {
-                        let isMobile = window.innerWidth < 768;
-                        if (isMobile !== currentIsMobile) {
-                            currentIsMobile = isMobile;
-                            dotNetHelper.invokeMethodAsync('OnViewportChanged', isMobile);
-                        }
-                    });
-                }
-            ");
-            await JS.InvokeVoidAsync("registerCanvasViewportObserver", _selfReference);
         }
         catch (Exception ex)
         {
@@ -194,12 +198,15 @@
         }
     }
 
+    private IJSObjectReference? _scrollListenerReference;
+
     private async Task InitializeObserverAsync()
     {
         try
         {
             var module = await JS.InvokeAsync<IJSObjectReference>("import", "./_content/NexusReader.UI.Shared/js/readerObserver.js");
             await module.InvokeVoidAsync("initObserver", DotNetObjectReference.Create(this), ".reader-flow-container", ".block-wrapper");
+            _scrollListenerReference = await module.InvokeAsync<IJSObjectReference>("initScrollListener", DotNetObjectReference.Create(this), ".reader-flow-container");
         }
         catch (Exception ex)
         {
@@ -207,10 +214,19 @@
         }
     }
 
+    [JSInvokable]
+    public async Task HandleScrollPercentChanged(int percent)
+    {
+        StateService.CurrentScrollPercentage = percent;
+        await InteractionService.NotifyScrollPercentChanged(percent);
+    }
+
     [JSInvokable]
     public async Task HandleBlockReached(string blockId, string content)
     {
         _currentActiveBlockId = blockId;
+        StateService.CurrentBlockId = blockId;
+        await InteractionService.NotifyBlockReached(blockId);
         await Coordinator.OnBlockReachedAsync(blockId, content);
 
         if (ViewModel != null)
@@ -310,6 +326,13 @@
             ViewModel = result.Value;
             await NavigationService.UpdateMetadataAsync(ViewModel.CurrentChapterIndex, ViewModel.TotalChapters, ViewModel.ChapterTitle);
 
+            // Populate checkpoints!
+            var checkpoints = ViewModel.Blocks
+                .Where(b => !string.IsNullOrEmpty(b.Id) && b.Id.Contains("seg"))
+                .Select(b => b.Id)
+                .ToList();
+            StateService.CurrentCheckpoints = checkpoints;
+
             if (_isInteractive)
             {
                 await Coordinator.ProcessFullPageAsync(GetFullPageContent(), ebookId: ViewModel.EbookId);
@@ -342,7 +365,8 @@
     {
         try
         {
-            await JS.InvokeVoidAsync("eval", $"document.getElementById('{id}')?.scrollIntoView({{ behavior: 'smooth', block: 'center' }});");
+            var module = _viewportModule ?? await JS.InvokeAsync<IJSObjectReference>("import", "./_content/NexusReader.UI.Shared/js/viewport.js");
+            await module.InvokeVoidAsync("scrollIntoView", id);
         }
         catch (Exception ex)
         {
@@ -352,12 +376,20 @@
 
     private Task HandleUpdate() => InvokeAsync(StateHasChanged);
 
+    private void HandleEscape()
+    {
+        if (ViewModel != null)
+        {
+            Navigation.NavigateTo("/");
+        }
+    }
+
     private async Task HandleAssistantFabClick()
     {
         await InteractionService.RequestAssistant();
     }
 
-    public void Dispose()
+    public async ValueTask DisposeAsync()
     {
         ThemeService.OnThemeChanged -= HandleUpdate;
         NavigationService.OnNavigationChanged -= OnNavigationChanged;
@@ -367,6 +399,32 @@
         InteractionService.OnHighlightBlockRequested -= HandleHighlightRequested;
         InteractionService.OnTextSelected -= HandleTextSelected;
         SyncService.OnProgressReceived -= HandleSyncProgressReceived;
+
+        try
+        {
+            if (_viewportModule != null)
+            {
+                if (_selfReference != null)
+                {
+                    await _viewportModule.InvokeVoidAsync("unregisterViewportObserver", _selfReference);
+                }
+                await _viewportModule.DisposeAsync();
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.LogDebug(ex, "Teardown of viewport observer module failed in ReaderCanvas disposal.");
+        }
+
+        try
+        {
+            if (_scrollListenerReference != null)
+            {
+                await _scrollListenerReference.DisposeAsync();
+            }
+        }
+        catch { }
+
         _selfReference?.Dispose();
     }
 }

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

@@ -258,4 +258,118 @@
 @keyframes fadeIn {
     from { opacity: 0; }
     to { opacity: 1; }
+}
+
+/* MOBILE READER UI OVERRIDES */
+@media (max-width: 768px) {
+    .reader-canvas {
+        padding-top: 54px !important;
+        padding-bottom: 80px !important; /* Ensure content is clear of bottom toolbar */
+    }
+
+    .reader-flow-container {
+        padding-bottom: 4rem; /* Safe breathing room */
+    }
+}
+
+.nexus-mobile-reader-header {
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100vw;
+    height: 50px;
+    background: rgba(18, 18, 18, 0.75);
+    backdrop-filter: blur(20px);
+    -webkit-backdrop-filter: blur(20px);
+    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
+    display: flex;
+    align-items: center;
+    padding: 0 1rem;
+    z-index: 1000;
+    box-sizing: border-box;
+}
+
+.theme-light .nexus-mobile-reader-header {
+    background: rgba(249, 249, 249, 0.8);
+    border-bottom-color: rgba(0, 0, 0, 0.08);
+}
+
+.nexus-mobile-escape-btn {
+    background: none;
+    border: none;
+    display: flex;
+    align-items: center;
+    gap: 4px;
+    color: var(--nexus-neon, #00FF99);
+    font-size: 0.8rem;
+    font-weight: 600;
+    cursor: pointer;
+    padding: 8px 12px;
+    border-radius: 8px;
+    transition: background-color 0.2s ease;
+    margin-left: -8px;
+}
+
+.nexus-mobile-escape-btn:active {
+    background-color: rgba(0, 255, 153, 0.08);
+}
+
+.nexus-mobile-chapter-navigation {
+    flex: 1;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 0.25rem;
+    height: 100%;
+    min-width: 0;
+}
+
+.nexus-mobile-chapter-title {
+    flex: 1;
+    text-align: center;
+    font-size: 0.8rem;
+    font-weight: 600;
+    color: #FFFFFF;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    padding: 0 0.5rem;
+    min-width: 0;
+}
+
+.theme-light .nexus-mobile-chapter-title {
+    color: #1a1a1a;
+}
+
+.nexus-chapter-nav-btn {
+    background: none;
+    border: none;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 28px;
+    height: 28px;
+    border-radius: 50%;
+    color: rgba(255, 255, 255, 0.5);
+    cursor: pointer;
+    transition: all 0.2s ease;
+    padding: 0;
+}
+
+.nexus-chapter-nav-btn:hover:not(:disabled) {
+    color: var(--nexus-neon, #00FF99);
+    background: rgba(255, 255, 255, 0.06);
+}
+
+.nexus-chapter-nav-btn:disabled {
+    opacity: 0.2;
+    cursor: not-allowed;
+}
+
+.theme-light .nexus-chapter-nav-btn {
+    color: rgba(0, 0, 0, 0.5);
+}
+
+.theme-light .nexus-chapter-nav-btn:hover:not(:disabled) {
+    background: rgba(0, 0, 0, 0.06);
 }

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

@@ -1,6 +1,7 @@
 @inherits LayoutComponentBase
 @using NexusReader.Application.Abstractions.Services
 @using NexusReader.UI.Shared.Services
+@using NexusReader.UI.Shared.Models
 @using NexusReader.UI.Shared.Components.Molecules
 @using NexusReader.UI.Shared.Components.Organisms
 @using NexusReader.Application.Queries.Graph
@@ -9,12 +10,14 @@
 @inject IFocusModeService FocusMode
 @inject IQuizStateService QuizService
 @inject IReaderInteractionService InteractionService
+@inject IReaderStateService StateService
 @inject IKnowledgeGraphService GraphService
 @inject IJSRuntime JS
 @inject IIdentityService IdentityService
 @inject NavigationManager NavigationManager
 @inject Microsoft.Extensions.Logging.ILogger<ReaderLayout> Logger
-@implements IDisposable
+@implements IAsyncDisposable
+
 
 <div class="app-container @_platformClass @(FocusMode.IsFocusModeActive ? "focus-mode-active" : "") @($"active-mobile-tab-{_activeMobileTab.ToString().ToLower()}")">
     <div class="reader-pane">
@@ -141,8 +144,8 @@
                         <KnowledgeGraph />
                     </div>
 
-                    <!-- Tab 3: Insight (Contextual Intelligence AND Knowledge Quiz) -->
+                    <!-- Tab 3: Concepts/Quiz -->
-                    <div class="nexus-mobile-tab-content insight-tab @(_activeMobileTab == MobileReaderTab.Insight ? "active" : "")">
+                    <div class="nexus-mobile-tab-content insight-tab @(_activeMobileTab == MobileReaderTab.Concepts ? "active" : "")">
                         <div class="mobile-insight-container">
                             <div class="mobile-insight-header">
                                 <div class="mobile-insight-nav">
@@ -223,27 +226,14 @@
                     </div>
                 </div>
 
-                <!-- Three-Tab Fixed Bottom Navigation Bar -->
+                <MobileReaderToolbar 
-                <div class="nexus-mobile-bottom-nav">
+                    ScrollPercentage="@_scrollPercentage"
-                    <button class="bottom-nav-item @(_activeMobileTab == MobileReaderTab.Reader ? "active" : "")" @onclick="() => SetMobileTab(MobileReaderTab.Reader)">
+                    ActiveTab="@_activeMobileTab"
-                        <NexusIcon Name="book-open" Size="20" />
+                    OnTabChanged="SetMobileTab"
-                        <span>Czytnik</span>
+                    OnAssistantClick="OpenAssistant"
-                    </button>
+                    Checkpoints="@StateService.CurrentCheckpoints" />
-                    <button class="bottom-nav-item @(_activeMobileTab == MobileReaderTab.Graph ? "active" : "")" @onclick="() => SetMobileTab(MobileReaderTab.Graph)">
+
-                        <NexusIcon Name="network" Size="20" />
+                <GlobalIntelligence IsOpen="@_isAssistantOpen" OnClose="CloseAssistant" />
-                        <span>Wykres</span>
-                    </button>
-                    <button class="bottom-nav-item @(_activeMobileTab == MobileReaderTab.Insight ? "active" : "")" @onclick="() => SetMobileTab(MobileReaderTab.Insight)">
-                        <span class="insight-icon-wrapper">
-                            <NexusIcon Name="brain" Size="20" />
-                            @if (QuizService.HasNewQuiz)
-                            {
-                                <span class="nav-quiz-indicator"></span>
-                            }
-                        </span>
-                        <span>Analiza</span>
-                    </button>
-                </div>
             }
         </Authorized>
         <Authorizing>
@@ -268,21 +258,28 @@
         Quiz
     }
 
-    private enum MobileReaderTab
-    {
-        Reader,
-        Graph,
-        Insight
-    }
-
     private SidebarTab _activeTab = SidebarTab.Knowledge;
-    private MobileReaderTab _activeMobileTab = MobileReaderTab.Reader;
     private string? _selectedNodeId;
     private GraphNodeDto? _selectedNode;
 
     private string _platformClass = "platform-desktop";
     private bool _isMobile = false;
     private DotNetObjectReference<ReaderLayout>? _selfReference;
+    private IJSObjectReference? _viewportModule;
+
+    private bool _isAssistantOpen;
+
+    private int _scrollPercentage
+    {
+        get => StateService.CurrentScrollPercentage;
+        set => StateService.CurrentScrollPercentage = value;
+    }
+
+    private MobileReaderTab _activeMobileTab
+    {
+        get => StateService.ActiveTab;
+        set => StateService.ActiveTab = value;
+    }
 
     protected override void OnInitialized()
     {
@@ -292,6 +289,7 @@
 
         InteractionService.OnNodeSelected += HandleNodeSelectedAsync;
         InteractionService.OnAssistantRequested += HandleAssistantRequestedAsync;
+        InteractionService.OnScrollPercentChanged += HandleScrollPercentChanged;
         GraphService.OnGraphUpdated += HandleGraphUpdatedAsync;
 
         var context = PlatformService.GetDeviceContext();
@@ -319,20 +317,45 @@
         StateHasChanged();
     }
 
+    private void OpenAssistant()
+    {
+        _isAssistantOpen = true;
+        StateHasChanged();
+    }
+
+    private void CloseAssistant()
+    {
+        _isAssistantOpen = false;
+        StateHasChanged();
+    }
+
+    private async Task HandleScrollPercentChanged(int percent)
+    {
+        _scrollPercentage = percent;
+        await InvokeAsync(StateHasChanged);
+    }
+
     private async Task HandleQuizRequestedAsync(string blockId)
     {
         _activeTab = SidebarTab.Quiz;
         if (_isMobile)
         {
-            _activeMobileTab = MobileReaderTab.Insight;
+            _activeMobileTab = MobileReaderTab.Concepts;
         }
         await InvokeAsync(StateHasChanged);
     }
 
     private async Task HandleAssistantRequestedAsync()
     {
-        _activeMobileTab = MobileReaderTab.Insight;
+        if (_isMobile)
-        _activeTab = SidebarTab.Quiz;
+        {
+            OpenAssistant();
+        }
+        else
+        {
+            _activeMobileTab = MobileReaderTab.Concepts;
+            _activeTab = SidebarTab.Quiz;
+        }
         await InvokeAsync(StateHasChanged);
     }
 
@@ -345,7 +368,7 @@
         }
         if (_isMobile)
         {
-            _activeMobileTab = MobileReaderTab.Insight;
+            _activeMobileTab = MobileReaderTab.Concepts;
             _activeTab = SidebarTab.Knowledge;
         }
         await InvokeAsync(StateHasChanged);
@@ -372,31 +395,27 @@
                 Logger.LogError(ex, "Failed to initialize layout resizer JS module.");
             }
 
-            await InitViewportDetectionAsync();
+            try
+            {
+                _viewportModule = await JS.InvokeAsync<IJSObjectReference>("import", "./_content/NexusReader.UI.Shared/js/viewport.js");
+                await InitViewportDetectionAsync();
+            }
+            catch (Exception ex)
+            {
+                Logger.LogError(ex, "Failed to import viewport utilities JS module.");
+            }
         }
     }
 
     private async Task InitViewportDetectionAsync()
     {
+        if (_viewportModule == null) return;
         try
         {
             _selfReference = DotNetObjectReference.Create(this);
-            var isMobileViewport = await JS.InvokeAsync<bool>("eval", "window.innerWidth < 768");
+            var isMobileViewport = await _viewportModule.InvokeAsync<bool>("isMobileViewport");
             await OnViewportChanged(isMobileViewport);
-
+            await _viewportModule.InvokeVoidAsync("registerViewportObserver", _selfReference);
-            await JS.InvokeVoidAsync("eval", @"
-                window.registerViewportObserver = (dotNetHelper) => {
-                    let currentIsMobile = window.innerWidth < 768;
-                    window.addEventListener('resize', () => {
-                        let isMobile = window.innerWidth < 768;
-                        if (isMobile !== currentIsMobile) {
-                            currentIsMobile = isMobile;
-                            dotNetHelper.invokeMethodAsync('OnViewportChanged', isMobile);
-                        }
-                    });
-                }
-            ");
-            await JS.InvokeVoidAsync("registerViewportObserver", _selfReference);
         }
         catch (Exception ex)
         {
@@ -417,14 +436,34 @@
 
     private Task HandleUpdate() => InvokeAsync(StateHasChanged);
 
-    public void Dispose()
+    public async ValueTask DisposeAsync()
     {
         FocusMode.OnFocusModeChanged -= HandleUpdate;
         QuizService.OnQuizUpdated -= HandleUpdate;
         QuizService.OnQuizRequested -= HandleQuizRequestedAsync;
         InteractionService.OnNodeSelected -= HandleNodeSelectedAsync;
         InteractionService.OnAssistantRequested -= HandleAssistantRequestedAsync;
+        InteractionService.OnScrollPercentChanged -= HandleScrollPercentChanged;
         GraphService.OnGraphUpdated -= HandleGraphUpdatedAsync;
+
+        try
+        {
+            if (_viewportModule != null)
+            {
+                if (_selfReference != null)
+                {
+                    await _viewportModule.InvokeVoidAsync("unregisterViewportObserver", _selfReference);
+                }
+                await _viewportModule.DisposeAsync();
+            }
+        }
+        catch (Exception ex)
+        {
+            Logger.LogDebug(ex, "Teardown of viewport observer module failed during component disposal.");
+        }
+
         _selfReference?.Dispose();
     }
 }
+
+

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

@@ -479,7 +479,7 @@ main {
 
 .platform-mobile .reader-pane {
     width: 100vw !important;
-    height: calc(100vh - 60px) !important; /* reserve bottom nav height */
+    height: 100vh !important; /* full viewport height */
     position: absolute;
     top: 0;
     left: 0;
@@ -496,7 +496,7 @@ main {
     display: block;
 }
 
-.app-container.platform-mobile.active-mobile-tab-insight .nexus-mobile-reader-tabs .insight-tab {
+.app-container.platform-mobile.active-mobile-tab-concepts .nexus-mobile-reader-tabs .insight-tab {
     display: block;
 }
 
@@ -508,7 +508,7 @@ main {
 .platform-mobile .nexus-mobile-reader-tabs {
     display: none; /* Keep hidden by default */
     width: 100vw;
-    height: calc(100vh - 60px);
+    height: 100vh; /* full viewport height */
     position: absolute;
     top: 0;
     left: 0;
@@ -518,8 +518,8 @@ main {
 }
 
 .app-container.platform-mobile.active-mobile-tab-graph .nexus-mobile-reader-tabs,
-.app-container.platform-mobile.active-mobile-tab-insight .nexus-mobile-reader-tabs {
+.app-container.platform-mobile.active-mobile-tab-concepts .nexus-mobile-reader-tabs {
-    display: block; /* Show only when graph or insight tabs are active */
+    display: block; /* Show only when graph or concepts tabs are active */
 }
 
 .nexus-mobile-tab-content {
@@ -553,7 +553,17 @@ main {
     background: #09090b;
 }
 
-.nexus-mobile-tab-content.graph-tab :deep(svg) {
+.nexus-mobile-tab-content.graph-tab ::deep .knowledge-graph-container {
+    height: 100% !important;
+    min-height: 100% !important;
+}
+
+.nexus-mobile-tab-content.graph-tab ::deep .graph-controls {
+    bottom: 6.5rem !important;
+    right: 1.5rem !important;
+}
+
+.nexus-mobile-tab-content.graph-tab ::deep svg {
     width: 100% !important;
     height: 100% !important;
 }
@@ -637,121 +647,4 @@ main {
     overflow-y: auto;
 }
 
-/* Three-Tab Bottom Navigation Bar styling */
+/* Obsolescence managed: consolidated mobile toolbar and sheet styled inside respective components */
-.nexus-mobile-bottom-nav {
-    display: none;
-}
-
-.platform-mobile .nexus-mobile-bottom-nav {
-    display: flex;
-    justify-content: space-around;
-    align-items: center;
-    position: absolute;
-    bottom: 0;
-    left: 0;
-    width: 100vw;
-    height: 60px;
-    background: rgba(13, 13, 13, 0.95);
-    backdrop-filter: blur(16px);
-    border-top: 1px solid rgba(255, 255, 255, 0.05);
-    z-index: 100;
-}
-
-.bottom-nav-item {
-    flex: 1;
-    display: flex;
-    flex-direction: column;
-    align-items: center;
-    justify-content: center;
-    gap: 0.25rem;
-    height: 100%;
-    background: none;
-    border: none;
-    color: rgba(255, 255, 255, 0.4);
-    font-family: var(--nexus-font-sans, "Outfit", sans-serif);
-    font-size: 0.65rem;
-    font-weight: 500;
-    cursor: pointer;
-    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
-}
-
-.bottom-nav-item.active {
-    color: var(--nexus-neon, #00f0ff);
-    text-shadow: 0 0 10px rgba(0, 240, 255, 0.2);
-}
-
-.bottom-nav-item.active :deep(svg) {
-    filter: drop-shadow(0 0 5px var(--nexus-neon, #00f0ff));
-}
-
-.insight-icon-wrapper {
-    position: relative;
-    display: inline-flex;
-    align-items: center;
-    justify-content: center;
-}
-
-.nav-quiz-indicator {
-    position: absolute;
-    top: -2px;
-    right: -2px;
-    width: 8px;
-    height: 8px;
-    background-color: #f43f5e;
-    border-radius: 50%;
-    box-shadow: 0 0 8px #f43f5e;
-    animation: indicator-flash 1.5s infinite ease-in-out;
-}
-
-@keyframes indicator-flash {
-    0% { transform: scale(0.8); opacity: 0.6; }
-    50% { transform: scale(1.2); opacity: 1; }
-    100% { transform: scale(0.8); opacity: 0.6; }
-}
-
-/* Assistant FAB styling inside ReaderCanvas */
-:global(.nexus-mobile-assistant-fab) {
-    position: fixed;
-    bottom: 75px;
-    right: 20px;
-    width: 56px;
-    height: 56px;
-    border-radius: 50%;
-    background: linear-gradient(135deg, rgba(0, 240, 255, 0.15) 0%, rgba(0, 100, 255, 0.15) 100%);
-    border: 1px solid rgba(0, 240, 255, 0.4);
-    box-shadow: 0 4px 20px rgba(0, 240, 255, 0.25);
-    display: flex;
-    align-items: center;
-    justify-content: center;
-    cursor: pointer;
-    z-index: 99;
-    backdrop-filter: blur(8px);
-    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
-}
-
-:global(.nexus-mobile-assistant-fab:hover) {
-    transform: scale(1.1) translateY(-2px);
-    box-shadow: 0 8px 25px rgba(0, 240, 255, 0.4);
-    border-color: var(--nexus-neon, #00f0ff);
-}
-
-:global(.nexus-mobile-assistant-fab:active) {
-    transform: scale(0.95);
-}
-
-:global(.nexus-mobile-assistant-fab.has-new-quiz) {
-    border-color: #f43f5e;
-    box-shadow: 0 4px 20px rgba(244, 63, 94, 0.3);
-}
-
-:global(.nexus-mobile-assistant-fab .fab-badge) {
-    position: absolute;
-    top: 2px;
-    right: 2px;
-    width: 10px;
-    height: 10px;
-    background-color: #f43f5e;
-    border-radius: 50%;
-    box-shadow: 0 0 10px #f43f5e;
-    animation: indicator-flash 1.5s infinite ease-in-out;
-}

src/NexusReader.UI.Shared/Models/ReaderModels.cs

@@ -0,0 +1,41 @@
+using NexusReader.Application.DTOs.AI;
+
+namespace NexusReader.UI.Shared.Models;
+
+/// <summary>
+/// Defines the active tab state for the unified mobile reader toolbar.
+/// </summary>
+public enum MobileReaderTab
+{
+    Reader,
+    Graph,
+    Concepts
+}
+
+/// <summary>
+/// Screen coordinates for text selection popup positioning.
+/// </summary>
+public record SelectionCoordinates(double Top, double Left, double Width);
+
+/// <summary>
+/// Represents a message in the KM-RAG global and mobile intelligence chat threads.
+/// </summary>
+public class ChatMessage
+{
+    public string Id { get; set; } = Guid.NewGuid().ToString();
+    public string Sender { get; set; } = string.Empty; // "User" or "AI"
+    public string Text { get; set; } = string.Empty;
+    public DateTime Timestamp { get; set; } = DateTime.UtcNow;
+    public List<ResponseSegment> Segments { get; set; } = new();
+    public List<CitationDto> Citations { get; set; } = new();
+}
+
+/// <summary>
+/// Represents a parsed segment of an intelligence response, potentially referencing a citation.
+/// </summary>
+public class ResponseSegment
+{
+    public string Text { get; set; } = string.Empty;
+    public bool IsCitation { get; set; }
+    public string CitationId { get; set; } = string.Empty;
+}

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

@@ -4,6 +4,7 @@
 @using NexusReader.Application.Abstractions.Services
 @using NexusReader.Application.DTOs.User
 @using NexusReader.UI.Shared.Components.Atoms
+@using NexusReader.UI.Shared.Models
 @using System.Net.Http.Json
 @inject HttpClient Http
 @inject IKnowledgeService KnowledgeService
@@ -145,22 +146,7 @@
     private List<LastReadBookDto>? _books;
     private List<ChatMessage> _chatMessages = new();
 
-    public class ChatMessage
-    {
-        public string Id { get; set; } = Guid.NewGuid().ToString();
-        public string Sender { get; set; } = string.Empty; // "User" or "AI"
-        public string Text { get; set; } = string.Empty;
-        public DateTime Timestamp { get; set; } = DateTime.UtcNow;
-        public List<ResponseSegment> Segments { get; set; } = new();
-        public List<CitationDto> Citations { get; set; } = new();
-    }
 
-    public class ResponseSegment
-    {
-        public string Text { get; set; } = string.Empty;
-        public bool IsCitation { get; set; }
-        public string CitationId { get; set; } = string.Empty;
-    }
 
     protected override async Task OnInitializedAsync()
     {

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

@@ -109,21 +109,16 @@ else
 
     private void LogInfo()
     {
-#if DEBUG
         Logger.LogInformation("Structured native log triggered by user from SerilogDemo. Button: LogInfo");
-#endif
     }
 
     private void LogWarning()
     {
-#if DEBUG
         Logger.LogWarning("Potential warning log triggered from Blazor razor component at {Time}", DateTime.UtcNow);
-#endif
     }
 
     private void LogError()
     {
-#if DEBUG
         try
         {
             throw new InvalidOperationException("Simulated native C# operation exception triggered in Diagnostic dashboard.");
@@ -132,22 +127,31 @@ else
         {
             Logger.LogError(ex, "Captured exception successfully in native Serilog pipeline!");
         }
-#endif
     }
 
     private async Task TriggerJsLog()
     {
-#if DEBUG
+        try
-        await JSRuntime.InvokeVoidAsync("console.log", "Intercepted JS console statement from Blazor WebView interop trigger!");
+        {
-#endif
+            await JSRuntime.InvokeVoidAsync("console.log", "Intercepted JS console statement from Blazor WebView interop trigger!");
-        await Task.CompletedTask;
+        }
+        catch (Exception ex)
+        {
+            Logger.LogWarning(ex, "Failed to execute console.log from diagnostic panel.");
+        }
     }
 
     private async Task TriggerJsException()
     {
-#if DEBUG
+        try
-        await JSRuntime.InvokeVoidAsync("eval", "throw new Error('Simulated runtime JS Exception triggered from Blazor UI button click!');");
+        {
-#endif
+            // Triggers a TypeError by invoking a non-existent method, which is completely CSP-compliant and works without eval()
-        await Task.CompletedTask;
+            await JSRuntime.InvokeVoidAsync("window.nonExistentFunctionTriggeringException");
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError(ex, "Simulated runtime JS Exception triggered and captured in Blazor UI");
+        }
     }
 }
+

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

@@ -1,3 +1,5 @@
+using NexusReader.UI.Shared.Models;
+
 namespace NexusReader.UI.Shared.Services;
 
 public interface IReaderInteractionService
@@ -7,12 +9,15 @@ public interface IReaderInteractionService
     event Func<string, Task>? OnHighlightBlockRequested;
     event Func<string, string, SelectionCoordinates, Task>? OnTextSelected;
     event Func<Task>? OnAssistantRequested;
+    event Func<int, Task>? OnScrollPercentChanged;
+    event Func<string, Task>? OnBlockReached;
 
     Task NotifyNodeSelected(string nodeId);
     Task RequestScrollToBlock(string blockId);
     Task RequestHighlightBlock(string blockId);
     Task NotifyTextSelected(string text, string blockId, SelectionCoordinates coords);
     Task RequestAssistant();
+    Task NotifyScrollPercentChanged(int percent);
+    Task NotifyBlockReached(string blockId);
 }
 
-public record SelectionCoordinates(double Top, double Left, double Width);

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

@@ -0,0 +1,14 @@
+using NexusReader.UI.Shared.Models;
+
+namespace NexusReader.UI.Shared.Services;
+
+/// <summary>
+/// Service to maintain local UI state for the reader, separating state from event bus.
+/// </summary>
+public interface IReaderStateService
+{
+    int CurrentScrollPercentage { get; set; }
+    List<string> CurrentCheckpoints { get; set; }
+    string CurrentBlockId { get; set; }
+    MobileReaderTab ActiveTab { get; set; }
+}

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

@@ -1,3 +1,5 @@
+using NexusReader.UI.Shared.Models;
+
 namespace NexusReader.UI.Shared.Services;
 
 public sealed class ReaderInteractionService : IReaderInteractionService
@@ -7,6 +9,8 @@ public sealed class ReaderInteractionService : IReaderInteractionService
     public event Func<string, Task>? OnHighlightBlockRequested;
     public event Func<string, string, SelectionCoordinates, Task>? OnTextSelected;
     public event Func<Task>? OnAssistantRequested;
+    public event Func<int, Task>? OnScrollPercentChanged;
+    public event Func<string, Task>? OnBlockReached;
 
     public async Task NotifyNodeSelected(string nodeId)
     {
@@ -32,4 +36,15 @@ public sealed class ReaderInteractionService : IReaderInteractionService
     {
         if (OnAssistantRequested != null) await OnAssistantRequested();
     }
+
+    public async Task NotifyScrollPercentChanged(int percent)
+    {
+        if (OnScrollPercentChanged != null) await OnScrollPercentChanged(percent);
+    }
+
+    public async Task NotifyBlockReached(string blockId)
+    {
+        if (OnBlockReached != null) await OnBlockReached(blockId);
+    }
 }
+

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

@@ -0,0 +1,39 @@
+using NexusReader.UI.Shared.Models;
+
+namespace NexusReader.UI.Shared.Services;
+
+/// <summary>
+/// Thread-safe implementation of IReaderStateService.
+/// </summary>
+public sealed class ReaderStateService : IReaderStateService
+{
+    private readonly object _lock = new();
+    private int _scrollPercent;
+    private List<string> _checkpoints = new();
+    private string _blockId = string.Empty;
+    private MobileReaderTab _activeTab = MobileReaderTab.Reader;
+
+    public int CurrentScrollPercentage
+    {
+        get { lock (_lock) return _scrollPercent; }
+        set { lock (_lock) _scrollPercent = value; }
+    }
+
+    public List<string> CurrentCheckpoints
+    {
+        get { lock (_lock) return _checkpoints; }
+        set { lock (_lock) _checkpoints = value ?? new(); }
+    }
+
+    public string CurrentBlockId
+    {
+        get { lock (_lock) return _blockId; }
+        set { lock (_lock) _blockId = value ?? string.Empty; }
+    }
+
+    public MobileReaderTab ActiveTab
+    {
+        get { lock (_lock) return _activeTab; }
+        set { lock (_lock) _activeTab = value; }
+    }
+}

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

@@ -200,6 +200,9 @@ export function mount(containerId, data, dotNetHelper) {
     width = container.clientWidth || 400;
     height = container.clientHeight || 400;
 
+    // Clean up any existing SVG to prevent duplicates
+    container.querySelectorAll("svg").forEach(el => el.remove());
+
     // Create SVG
     svgElement = d3.select(container).append("svg")
         .attr("viewBox", [0, 0, width, height])

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

@@ -20,3 +20,43 @@ export function initObserver(dotNetHelper, containerSelector, itemSelector) {
 
     return observer;
 }
+
+export function initScrollListener(dotNetHelper, scrollContainerSelector) {
+    const container = document.querySelector(scrollContainerSelector);
+    if (!container) return null;
+
+    let isThrottled = false;
+
+    const onScroll = () => {
+        if (isThrottled) return;
+        isThrottled = true;
+
+        requestAnimationFrame(() => {
+            const scrollTop = container.scrollTop;
+            const scrollHeight = container.scrollHeight;
+            const clientHeight = container.clientHeight;
+
+            let percentage = 0;
+            if (scrollHeight > clientHeight) {
+                percentage = Math.round((scrollTop / (scrollHeight - clientHeight)) * 100);
+            }
+
+            // Ensure bounds
+            percentage = Math.max(0, Math.min(100, percentage));
+
+            dotNetHelper.invokeMethodAsync('HandleScrollPercentChanged', percentage);
+            isThrottled = false;
+        });
+    };
+
+    container.addEventListener('scroll', onScroll, { passive: true });
+
+    // Initial calculation after a brief layout delay
+    setTimeout(onScroll, 100);
+
+    return {
+        dispose: () => {
+            container.removeEventListener('scroll', onScroll);
+        }
+    };
+}

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

@@ -0,0 +1,40 @@
+/**
+ * Viewport and scrolling utilities for NexusReader.
+ * Avoids eval() usage, supports CSP, AOT-safety, and prevents memory leaks.
+ */
+
+export function isMobileViewport() {
+    return window.innerWidth < 768;
+}
+
+export function registerViewportObserver(dotNetHelper) {
+    let currentIsMobile = window.innerWidth < 768;
+    
+    const listener = () => {
+        const isMobile = window.innerWidth < 768;
+        if (isMobile !== currentIsMobile) {
+            currentIsMobile = isMobile;
+            dotNetHelper.invokeMethodAsync('OnViewportChanged', isMobile);
+        }
+    };
+
+    // Store listener directly on the JS object wrapper of the DotNetObjectReference for elegant cleanup
+    dotNetHelper._viewportListener = listener;
+    window.addEventListener('resize', listener);
+}
+
+export function unregisterViewportObserver(dotNetHelper) {
+    if (dotNetHelper && dotNetHelper._viewportListener) {
+        window.removeEventListener('resize', dotNetHelper._viewportListener);
+        delete dotNetHelper._viewportListener;
+    }
+}
+
+export function scrollIntoView(id) {
+    const el = document.getElementById(id);
+    if (el) {
+        el.scrollIntoView({ behavior: 'smooth', block: 'center' });
+        return true;
+    }
+    return false;
+}

src/NexusReader.Web.Client/Program.cs

@@ -23,6 +23,7 @@ builder.Services.AddScoped<IFocusModeService, FocusModeService>();
 builder.Services.AddScoped<IReaderNavigationService, ReaderNavigationService>();
 builder.Services.AddScoped<IKnowledgeGraphService, KnowledgeGraphService>();
 builder.Services.AddScoped<IReaderInteractionService, ReaderInteractionService>();
+builder.Services.AddScoped<IReaderStateService, ReaderStateService>();
 builder.Services.AddScoped<KnowledgeCoordinator>();
 builder.Services.AddScoped<ISyncService, SyncService>();
 

src/NexusReader.Web.Client/wwwroot/js/knowledgeGraph.js

@@ -9,6 +9,9 @@ export function mount(containerId, data, dotNetHelper) {
     const width = container.clientWidth || 400;
     const height = container.clientHeight || 400;
 
+    // Clean up any existing SVG to prevent duplicates
+    container.querySelectorAll("svg").forEach(el => el.remove());
+
     // Create SVG
     const svg = d3.select(container).append("svg")
         .attr("viewBox", [0, 0, width, height])

src/NexusReader.Web/Program.cs

@@ -53,6 +53,7 @@ builder.Services.AddScoped<IFocusModeService, FocusModeService>();
 builder.Services.AddScoped<IReaderNavigationService, ReaderNavigationService>();
 builder.Services.AddScoped<IKnowledgeGraphService, KnowledgeGraphService>();
 builder.Services.AddScoped<IReaderInteractionService, ReaderInteractionService>();
+builder.Services.AddScoped<IReaderStateService, ReaderStateService>();
 builder.Services.AddScoped<KnowledgeCoordinator>();
 builder.Services.AddScoped<ISyncService, SyncService>();