Resolve merge conflicts for PR #25: customizable mobile reading experience

- Backend: Replace PR's Book-only models with main's full models
  (EBook, BookChapter, DownloadRecord, ReadingProgress, ReadingSettings)
- Backend: Add reader app (ReadingSettings model, serializer, view, URL)
- Frontend: Port reader feature files from web/ to frontend/ (api, hooks,
  components/reader/, pages/ReadingPage, types/reader, reader.css)
- Frontend: Add /read/:id route to App.tsx for chapter-based reading view
- All imports adjusted for frontend/src directory structure

backend/apps/books/models.py

@@ -1,11 +1,36 @@
+from django.conf import settings
 from django.db import models
+from django.db.models.signals import post_delete
+from django.dispatch import receiver
+from pathlib import Path
+
+
+class ReadingStatus(models.TextChoices):
+    WANT_TO_READ = "want_to_read", "Want to Read"
+    READING = "reading", "Reading"
+    FINISHED = "finished", "Finished"
+    DNF = "dnf", "Did Not Finish"
+
+
+class FontStyle(models.TextChoices):
+    SANS_SERIF = "sans-serif", "Sans Serif"
+    SERIF = "serif", "Serif"
+    MONOSPACE = "monospace", "Monospace"
+
+
+class BackgroundColor(models.TextChoices):
+    WHITE = "#ffffff", "White"
+    SEPIA = "#f4e4c1", "Sepia"
+    DARK = "#1a1a2e", "Dark"
+    GREEN = "#c7edcc", "Green"
 
 
 class Book(models.Model):
-    """Represents a book in the user's library."""
-
-    title = models.CharField(max_length=512)
-    author = models.CharField(max_length=256, blank=True, default="")
+    title = models.CharField(max_length=512, db_index=True)
+    author = models.CharField(max_length=256, blank=True, default="", db_index=True)
+    genre = models.CharField(max_length=128, blank=True, default="", db_index=True)
+    description = models.TextField(blank=True, default="")
+    reading_status = models.CharField(max_length=20, choices=ReadingStatus.choices, default=ReadingStatus.WANT_TO_READ, db_index=True)
     total_pages = models.PositiveIntegerField(default=0)
     cover_image = models.URLField(blank=True, default="")
     created_at = models.DateTimeField(auto_now_add=True)
@@ -16,6 +41,218 @@ class Book(models.Model):
         verbose_name = "Book"
         verbose_name_plural = "Books"
         ordering = ["title"]
+        indexes = [models.Index(fields=["title", "author", "genre"])]
 
-    def __str__(self) -> str:
-        return self.title
+    def __str__(self):
+        return self.title
+
+
+class EBook(models.Model):
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="ebooks")
+    title = models.CharField(max_length=512, db_index=True)
+    author = models.CharField(max_length=256, blank=True, default="", db_index=True)
+    format = models.CharField(max_length=20, blank=True, default="", editable=False)
+    page_count = models.PositiveIntegerField(default=0)
+    file_size = models.BigIntegerField(default=0)
+    metadata_json = models.JSONField(blank=True, default=dict)
+    file = models.FileField(upload_to="ebooks/%Y/%m/%d/")
+    cover_image = models.ImageField(upload_to="ebook_covers/%Y/%m/%d/", blank=True, null=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "books_ebook"
+        verbose_name = "E-Book"
+        verbose_name_plural = "E-Books"
+        ordering = ["-created_at"]
+        indexes = [models.Index(fields=["user", "-created_at"])]
+
+    def __str__(self):
+        return self.title
+
+    def filename(self):
+        return Path(self.file.name).name if self.file else ""
+
+
+class BookChapter(models.Model):
+    ebook = models.ForeignKey(EBook, on_delete=models.CASCADE, related_name="chapters")
+    title = models.CharField(max_length=512)
+    index = models.IntegerField(default=0)
+    href = models.CharField(max_length=1024, blank=True, default="")
+    children = models.JSONField(blank=True, default=list)
+
+    class Meta:
+        db_table = "books_book_chapter"
+        verbose_name = "Book Chapter"
+        verbose_name_plural = "Book Chapters"
+        ordering = ["index"]
+        indexes = [models.Index(fields=["ebook", "index"])]
+
+    def __str__(self):
+        return f"{self.ebook.title} - {self.title}"
+
+
+@receiver(post_delete, sender=EBook)
+def _auto_delete_ebook_file(sender, instance, **kwargs):
+    if instance.file:
+        instance.file.delete(save=False)
+    if instance.cover_image:
+        instance.cover_image.delete(save=False)
+
+
+class DownloadRecord(models.Model):
+    """Tracks book downloads for offline access management."""
+
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="download_records")
+    ebook = models.ForeignKey(EBook, on_delete=models.CASCADE, related_name="download_records")
+    file_size = models.BigIntegerField(default=0)
+    downloaded_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "books_download_record"
+        verbose_name = "Download Record"
+        verbose_name_plural = "Download Records"
+        ordering = ["-downloaded_at"]
+        unique_together = [("user", "ebook")]
+
+    def __str__(self):
+        return f"{self.user} - {self.ebook.title}"
+
+
+class ReadingProgress(models.Model):
+    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="reading_progress")
+    ebook = models.OneToOneField(EBook, on_delete=models.CASCADE, related_name="reading_progress")
+    current_position = models.FloatField(default=0.0)
+    last_page = models.IntegerField(default=0)
+    device_id = models.CharField(max_length=128, blank=True, default="")
+    device_name = models.CharField(max_length=128, blank=True, default="")
+    version = models.PositiveIntegerField(default=1)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "books_reading_progress"
+        verbose_name_plural = "reading progress"
+        unique_together = [("user", "ebook")]
+
+    def __str__(self):
+        return f"{self.ebook.title} - {self.current_position:.1f}%"
+
+    def update_with_sync(self, position: float, last_page: int,
+                         device_id: str, device_name: str,
+                         client_updated_at: str | None = None) -> tuple["ReadingProgress", bool]:
+        """Update progress with conflict resolution (last-write-wins by timestamp).
+
+        Returns (instance, applied) where applied is True if the update was applied.
+        """
+        if client_updated_at and self.updated_at:
+            try:
+                from django.utils.timezone import is_naive, make_aware
+                from datetime import datetime
+                client_dt = datetime.fromisoformat(client_updated_at.replace("Z", "+00:00"))
+                if is_naive(client_dt):
+                    client_dt = make_aware(client_dt)
+                if client_dt <= self.updated_at:
+                    return self, False
+            except (ValueError, TypeError):
+                pass
+
+        self.current_position = position
+        self.last_page = last_page
+        self.device_id = device_id
+        self.device_name = device_name
+        self.version += 1
+        self.save(update_fields=[
+            "current_position", "last_page",
+            "device_id", "device_name", "version", "updated_at",
+        ])
+        return self, True
+
+
+class ReadingSettings(models.Model):
+    user = models.OneToOneField(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="reading_settings")
+    font_size = models.IntegerField(default=18)
+    font_style = models.CharField(max_length=20, choices=FontStyle.choices, default=FontStyle.SANS_SERIF.value)
+    background_color = models.CharField(max_length=7, choices=BackgroundColor.choices, default=BackgroundColor.WHITE.value)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "books_reading_settings"
+        verbose_name_plural = "reading settings"
+
+    def __str__(self):
+        return f"Settings for {self.user}"
+
+
+class Chapter(models.Model):
+    """A chapter within a book, containing the text/markdown content.
+
+    This is distinct from BookChapter (which tracks EPUB TOC entries).
+    Chapter represents user-authored chapter content for a Book.
+    """
+
+    book = models.ForeignKey(
+        Book,
+        on_delete=models.CASCADE,
+        related_name="chapters",
+        db_index=True,
+    )
+    title = models.CharField(max_length=512)
+    number = models.PositiveIntegerField()
+    content = models.TextField(blank=True, default="")
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "books_chapter"
+        verbose_name = "Chapter"
+        verbose_name_plural = "Chapters"
+        ordering = ["book", "number"]
+        constraints = [
+            models.UniqueConstraint(
+                fields=["book", "number"],
+                name="uq_book_chapter_number",
+            )
+        ]
+
+    def __str__(self):
+        return f"{self.book.title} — Ch. {self.number}: {self.title}"
+
+
+class BookReadingProgress(models.Model):
+    """Tracks a user's reading progress within a book's chapters.
+
+    This is distinct from ReadingProgress (which tracks ebook progress).
+    BookReadingProgress tracks chapter-based reading for Books.
+    """
+
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="book_reading_progress",
+        db_index=True,
+    )
+    book = models.ForeignKey(
+        Book,
+        on_delete=models.CASCADE,
+        related_name="book_reading_progress",
+        db_index=True,
+    )
+    current_chapter = models.PositiveIntegerField(default=1)
+    current_position = models.PositiveIntegerField(default=0)
+    percentage = models.FloatField(default=0.0)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "books_book_reading_progress"
+        verbose_name = "Book Reading Progress"
+        verbose_name_plural = "Book Reading Progress"
+        ordering = ["-updated_at"]
+        constraints = [
+            models.UniqueConstraint(
+                fields=["user", "book"],
+                name="uq_book_reading_progress_user_book",
+            )
+        ]
+
+    def __str__(self):
+        return f"{self.user} — {self.book.title} ({self.percentage:.0f}%)"

backend/apps/books/serializers.py

@@ -1,28 +1,228 @@
 from rest_framework import serializers
 
-from apps.books.models import Book
+from apps.books.models import Book, BookChapter, BookReadingProgress, Chapter, EBook, FontStyle, BackgroundColor, ReadingProgress, ReadingSettings, ReadingStatus, DownloadRecord
 
 
-class BookSerializer(serializers.ModelSerializer):
-    """Serialize Book data."""
-
+class BookChapterSerializer(serializers.ModelSerializer):
     class Meta:
-        model = Book
-        fields = [
-            "id",
-            "title",
-            "author",
-            "total_pages",
-            "cover_image",
-            "created_at",
-            "updated_at",
-        ]
-        read_only_fields = ["id", "created_at", "updated_at"]
+        model = BookChapter
+        fields = ["id", "title", "index", "href", "children"]
+
+
+class EBookContentSerializer(serializers.Serializer):
+    page = serializers.IntegerField()
+    total_pages = serializers.IntegerField()
+    content = serializers.CharField()
+    chapter_title = serializers.CharField()
+    format = serializers.CharField()
+
+
+class EBookTocSerializer(serializers.Serializer):
+    chapters = serializers.ListField(child=BookChapterSerializer())
+    format = serializers.CharField()
+    page_count = serializers.IntegerField()
 
 
 class BookListSerializer(serializers.ModelSerializer):
-    """Lightweight serializer for list views (excludes heavy fields)."""
+    reading_status_display = serializers.CharField(source="get_reading_status_display", read_only=True)
 
     class Meta:
         model = Book
-        fields = ["id", "title", "author", "total_pages", "cover_image"]
+        fields = ["id", "title", "author", "genre", "reading_status", "reading_status_display", "cover_image"]
+
+
+class BookDetailSerializer(serializers.ModelSerializer):
+    reading_status_display = serializers.CharField(source="get_reading_status_display", read_only=True)
+
+    class Meta:
+        model = Book
+        fields = ["id", "title", "author", "genre", "description", "reading_status", "reading_status_display", "cover_image", "total_pages", "created_at", "updated_at"]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class BookSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = Book
+        fields = ["id", "title", "author", "genre", "description", "reading_status", "cover_image", "total_pages", "created_at", "updated_at"]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class EBookListSerializer(serializers.ModelSerializer):
+    filename = serializers.CharField(read_only=True)
+    format = serializers.CharField(read_only=True)
+    progress = serializers.SerializerMethodField()
+
+    class Meta:
+        model = EBook
+        fields = ["id", "title", "author", "filename", "format", "page_count", "file_size", "cover_image", "created_at", "progress"]
+
+    def get_progress(self, obj):
+        try:
+            return obj.reading_progress.current_position
+        except ReadingProgress.DoesNotExist:
+            return None
+
+
+class EBookDetailSerializer(serializers.ModelSerializer):
+    filename = serializers.CharField(read_only=True)
+    format = serializers.CharField(read_only=True)
+    file_url = serializers.SerializerMethodField()
+    progress = serializers.SerializerMethodField()
+
+    class Meta:
+        model = EBook
+        fields = ["id", "title", "author", "filename", "format", "page_count", "file_size", "file_url", "cover_image", "created_at", "updated_at", "progress"]
+
+    def get_file_url(self, obj):
+        request = self.context.get("request")
+        if request and obj.file:
+            return request.build_absolute_uri(obj.file.url)
+        return ""
+
+    def get_progress(self, obj):
+        try:
+            rp = obj.reading_progress
+            return {"current_position": rp.current_position, "last_page": rp.last_page}
+        except ReadingProgress.DoesNotExist:
+            return None
+
+
+class EBookUploadSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = EBook
+        fields = ["title", "author", "file", "cover_image"]
+        extra_kwargs = {"title": {"required": True}, "file": {"required": True}}
+
+    def validate_file(self, value):
+        import os
+        if value is None:
+            return value
+        ext = os.path.splitext(str(getattr(value, "name", "")))[1].lower()
+        if ext not in (".epub", ".pdf"):
+            raise serializers.ValidationError("Only EPUB and PDF files are supported.")
+        return value
+
+    def create(self, validated_data):
+        validated_data["user"] = self.context["request"].user
+        # Auto-detect format from file extension
+        import os
+        name = str(getattr(validated_data.get("file"), "name", ""))
+        ext = os.path.splitext(name)[1].lower().lstrip(".")
+        if ext:
+            validated_data["format"] = ext
+        return super().create(validated_data)
+
+
+class ReadingProgressSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ReadingProgress
+        fields = ["current_position", "last_page", "device_id", "device_name", "version", "updated_at"]
+        read_only_fields = ["version", "updated_at"]
+        extra_kwargs = {"current_position": {"required": True, "min_value": 0.0, "max_value": 100.0}}
+
+    def validate_current_position(self, value):
+        if value < 0.0 or value > 100.0:
+            raise serializers.ValidationError("Position must be between 0.0 and 100.0.")
+        return value
+
+
+class ReadingSettingsSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = ReadingSettings
+        fields = ["font_size", "font_style", "background_color"]
+
+    def validate_font_size(self, value):
+        if value < 12 or value > 36:
+            raise serializers.ValidationError("Font size must be between 12 and 36.")
+        return value
+
+    def validate_font_style(self, value):
+        valid = [s.value for s in FontStyle]
+        if value not in valid:
+            raise serializers.ValidationError(f"Font style must be one of: {', '.join(valid)}")
+        return value
+
+    def validate_background_color(self, value):
+        valid = [c.value for c in BackgroundColor]
+        if value not in valid:
+            raise serializers.ValidationError(f"Background color must be one of: {', '.join(valid)}")
+        return value
+
+
+class DownloadRecordSerializer(serializers.ModelSerializer):
+    ebook_id = serializers.IntegerField(source="ebook.id", read_only=True)
+    ebook_title = serializers.CharField(source="ebook.title", read_only=True)
+    author = serializers.CharField(source="ebook.author", read_only=True)
+    filename = serializers.SerializerMethodField()
+    cover_image = serializers.ImageField(source="ebook.cover_image", read_only=True)
+    format = serializers.CharField(source="ebook.format", read_only=True)
+    progress = serializers.SerializerMethodField()
+    file_url = serializers.SerializerMethodField()
+
+    class Meta:
+        model = DownloadRecord
+        fields = [
+            "id", "ebook_id", "ebook_title", "author", "filename", "file_url",
+            "file_size", "cover_image", "format", "downloaded_at", "progress",
+        ]
+
+    def get_filename(self, obj):
+        return obj.ebook.filename()
+
+    def get_file_url(self, obj):
+        request = self.context.get("request")
+        if request and obj.ebook.file:
+            return request.build_absolute_uri(obj.ebook.file.url)
+        return ""
+
+    def get_progress(self, obj):
+        try:
+            rp = obj.ebook.reading_progress
+            return {"current_position": rp.current_position, "last_page": rp.last_page}
+        except ReadingProgress.DoesNotExist:
+            return None
+
+
+class StorageSummarySerializer(serializers.Serializer):
+    total_downloads = serializers.IntegerField()
+    total_size_bytes = serializers.IntegerField()
+    ebooks = serializers.ListField(child=serializers.DictField())
+
+
+class ChapterSummarySerializer(serializers.ModelSerializer):
+    """Compact serializer for TOC listing — no content body."""
+
+    class Meta:
+        model = Chapter
+        fields = ["id", "book", "title", "number"]
+
+
+class ChapterDetailSerializer(serializers.ModelSerializer):
+    """Full serializer with chapter content for reading view."""
+
+    class Meta:
+        model = Chapter
+        fields = ["id", "book", "title", "number", "content", "created_at", "updated_at"]
+        read_only_fields = ["id", "created_at", "updated_at"]
+
+
+class BookReadingProgressSerializer(serializers.ModelSerializer):
+    """Serialize chapter-based reading progress for a book."""
+
+    class Meta:
+        model = BookReadingProgress
+        fields = [
+            "id", "book", "current_chapter", "current_position",
+            "percentage", "updated_at",
+        ]
+        read_only_fields = ["id", "updated_at"]
+
+    def validate_percentage(self, value):
+        if value < 0.0 or value > 100.0:
+            raise serializers.ValidationError("Percentage must be between 0 and 100.")
+        return value
+
+    def validate_current_chapter(self, value):
+        if value < 1:
+            raise serializers.ValidationError("Chapter number must be positive.")
+        return value

backend/apps/books/views.py

@@ -1,24 +1,341 @@
-from django_filters.rest_framework import DjangoFilterBackend
-from rest_framework import viewsets
-from rest_framework.filters import OrderingFilter, SearchFilter
-from rest_framework.permissions import IsAuthenticated
+from __future__ import annotations
 
-from apps.books.models import Book
-from apps.books.serializers import BookListSerializer, BookSerializer
+import logging
+from typing import Any
+
+from django.db.models import QuerySet, Q
+from django_filters.rest_framework import DjangoFilterBackend
+from rest_framework import parsers, permissions, status, viewsets
+from rest_framework.decorators import action
+from rest_framework.filters import OrderingFilter, SearchFilter
+from rest_framework.permissions import AllowAny, IsAuthenticated
+from rest_framework.request import Request
+from rest_framework.response import Response
+
+from apps.books.models import Book, BookChapter, BookReadingProgress, DownloadRecord, EBook, Chapter, ReadingProgress, ReadingSettings
+from apps.books.serializers import (
+    BookChapterSerializer, BookDetailSerializer, BookListSerializer, BookSerializer,
+    BookReadingProgressSerializer, ChapterDetailSerializer, ChapterSummarySerializer,
+    DownloadRecordSerializer, EBookContentSerializer, EBookDetailSerializer,
+    EBookListSerializer, EBookTocSerializer, EBookUploadSerializer,
+    ReadingProgressSerializer, ReadingSettingsSerializer, StorageSummarySerializer,
+)
+
+logger = logging.getLogger(__name__)
 
 
 class BookViewSet(viewsets.ModelViewSet):
-    """CRUD for books."""
-
     queryset = Book.objects.all()
     permission_classes = [IsAuthenticated]
     filter_backends = [DjangoFilterBackend, SearchFilter, OrderingFilter]
-    filterset_fields = ["author"]
-    search_fields = ["title", "author"]
-    ordering_fields = ["title", "author", "created_at"]
+    filterset_fields = ["author", "genre", "reading_status"]
+    search_fields = ["title", "author", "genre"]
+    ordering_fields = ["title", "author", "genre", "created_at"]
     ordering = ["title"]
 
     def get_serializer_class(self):
+        if self.action == "retrieve":
+            return BookDetailSerializer
         if self.action == "list":
             return BookListSerializer
-        return BookSerializer
+        return BookSerializer
+
+    def get_queryset(self) -> QuerySet[Book]:
+        qs = super().get_queryset()
+        query = self.request.query_params.get("q", "").strip()
+        if query:
+            qs = qs.filter(Q(title__icontains=query) | Q(author__icontains=query) | Q(genre__icontains=query))
+        return qs
+
+    @action(detail=False, methods=["get"], permission_classes=[AllowAny])
+    def genres(self, request: Request) -> Response:
+        genre_list = Book.objects.values_list("genre", flat=True).distinct().order_by("genre")
+        return Response([g for g in genre_list if g])
+
+    @action(detail=False, methods=["get"], permission_classes=[AllowAny])
+    def authors(self, request: Request) -> Response:
+        author_list = Book.objects.values_list("author", flat=True).distinct().order_by("author")
+        return Response([a for a in author_list if a])
+
+    @action(detail=False, methods=["get"])
+    def storage(self, request: Request) -> Response:
+        """Return storage usage summary for the current user."""
+        download_records = DownloadRecord.objects.filter(user=request.user).select_related("ebook")
+        total_size = sum(r.file_size for r in download_records)
+        ebook_list = [
+            {"id": r.ebook.id, "title": r.ebook.title, "file_size": r.file_size}
+            for r in download_records
+        ]
+        serializer = StorageSummarySerializer(data={
+            "total_downloads": download_records.count(),
+            "total_size_bytes": total_size,
+            "ebooks": ebook_list,
+        })
+        serializer.is_valid(raise_exception=True)
+        return Response(serializer.data)
+
+
+    @action(detail=True, methods=["get"])
+    def chapters(self, request: Request, pk: int | None = None) -> Response:
+        """List all chapters for this book (TOC)."""
+        book = self.get_object()
+        chapter_qs = Chapter.objects.filter(book=book).order_by("number")
+        serializer = ChapterSummarySerializer(chapter_qs, many=True)
+        return Response(serializer.data)
+
+    @action(detail=True, methods=["get"], url_path=r"chapters/(?P<chapter_number>[0-9]+)")
+    def chapter_detail(self, request: Request, pk: int | None = None, chapter_number: str | None = None) -> Response:
+        """Get a specific chapter with full content."""
+        book = self.get_object()
+        try:
+            chapter = Chapter.objects.get(book=book, number=int(chapter_number or "0"))
+        except Chapter.DoesNotExist:
+            return Response(
+                {"detail": "Chapter not found."}, status=status.HTTP_404_NOT_FOUND
+            )
+        serializer = ChapterDetailSerializer(chapter)
+        return Response(serializer.data)
+
+    @action(detail=True, methods=["get", "put"])
+    def progress(self, request: Request, pk: int | None = None) -> Response:
+        """Get or update chapter-based reading progress for this book."""
+        book = self.get_object()
+        progress_obj, _created = BookReadingProgress.objects.get_or_create(
+            user=request.user, book=book
+        )
+
+        if request.method == "GET":
+            serializer = BookReadingProgressSerializer(progress_obj)
+            return Response(serializer.data)
+
+        serializer = BookReadingProgressSerializer(
+            progress_obj, data=request.data, partial=True
+        )
+        serializer.is_valid(raise_exception=True)
+        serializer.save()
+        return Response(serializer.data, status=status.HTTP_200_OK)
+
+
+class IsEBookOwner(permissions.BasePermission):
+    def has_object_permission(self, request: Request, view: object, obj: EBook) -> bool:
+        return obj.user == request.user
+
+
+class EBookViewSet(viewsets.ModelViewSet):
+    parser_classes = [parsers.MultiPartParser, parsers.FormParser, parsers.JSONParser]
+    permission_classes = [IsAuthenticated, IsEBookOwner]
+
+    def get_serializer_class(self):
+        if self.action == "create":
+            return EBookUploadSerializer
+        if self.action in ("list",):
+            return EBookListSerializer
+        if self.action in ("toc",):
+            return BookChapterSerializer
+        return EBookDetailSerializer
+
+    def get_queryset(self):
+        return EBook.objects.filter(user=self.request.user).select_related("reading_progress", "user")
+
+    @action(detail=True, methods=["get", "patch"])
+    def progress(self, request: Request, pk: int | None = None) -> Response:
+        ebook = self.get_object()
+        progress_obj, _created = ReadingProgress.objects.get_or_create(user=request.user, ebook=ebook)
+        if request.method == "GET":
+            serializer = ReadingProgressSerializer(progress_obj)
+            return Response(serializer.data)
+        serializer = ReadingProgressSerializer(progress_obj, data=request.data, partial=True)
+        serializer.is_valid(raise_exception=True)
+        serializer.save()
+        return Response(serializer.data)
+
+    @action(detail=True, methods=["post"])
+    def process(self, request: Request, pk: int | None = None) -> Response:
+        """Trigger e-book processing: metadata extraction, TOC building, page counting."""
+        ebook = self.get_object()
+        if not ebook.file:
+            return Response({"error": "No file found for this e-book."}, status=status.HTTP_400_BAD_REQUEST)
+
+        try:
+            from apps.books.services import process_ebook
+
+            file_path = ebook.file.path
+            result = process_ebook(file_path, original_filename=ebook.filename())
+
+            # Update ebook with extracted data
+            ebook.format = result.get("format", ebook.format)
+            ebook.page_count = result.get("page_count", 0)
+            ebook.metadata_json = result.get("metadata", {})
+            ebook.save(update_fields=["format", "page_count", "metadata_json", "updated_at"])
+
+            # Store chapters in DB
+            raw_toc: list[dict[str, Any]] = result.get("toc", [])
+            BookChapter.objects.filter(ebook=ebook).delete()
+            _store_chapters(ebook, raw_toc)
+
+            return Response({
+                "format": ebook.format,
+                "page_count": ebook.page_count,
+                "metadata": ebook.metadata_json,
+                "toc_count": len(raw_toc),
+                "status": "processed",
+            })
+        except Exception as exc:
+            logger.exception("Failed to process ebook %s", ebook.id)
+            return Response({"error": f"Processing failed: {exc}"}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
+
+    @action(detail=True, methods=["get"])
+    def toc(self, request: Request, pk: int | None = None) -> Response:
+        """Return hierarchical table of contents."""
+        ebook = self.get_object()
+        chapters = BookChapter.objects.filter(ebook=ebook).order_by("index").select_related("ebook")
+        serializer = BookChapterSerializer(chapters, many=True)
+        return Response({
+            "chapters": serializer.data,
+            "format": ebook.format,
+            "page_count": ebook.page_count,
+        })
+
+    @action(detail=True, methods=["get"])
+    def content(self, request: Request, pk: int | None = None) -> Response:
+        """Return paginated content for a given page number.
+
+        Query params:
+            page (int): page/chapter index to fetch (1-indexed, default: 1)
+        """
+        ebook = self.get_object()
+        page = max(1, int(request.query_params.get("page", 1)))
+
+        chapters = list(BookChapter.objects.filter(ebook=ebook).order_by("index").select_related("ebook"))
+        total_pages = len(chapters) or ebook.page_count or 1
+
+        chapter: BookChapter | None = None
+        chapter_title = ""
+        content_html = ""
+
+        if chapters and 0 <= page - 1 < len(chapters):
+            ch = chapters[page - 1]
+            chapter_title = ch.title
+            content_html = _fetch_chapter_content(ebook, ch)
+
+        serializer = EBookContentSerializer(data={
+            "page": page,
+            "total_pages": total_pages,
+            "content": content_html,
+            "chapter_title": chapter_title,
+            "format": ebook.format,
+        })
+        serializer.is_valid(raise_exception=True)
+        return Response(serializer.data)
+
+    @action(detail=True, methods=["post"])
+    def download(self, request: Request, pk: int | None = None) -> Response:
+        """Track download of an e-book. Creates a DownloadRecord and returns file info."""
+        ebook = self.get_object()
+        if not ebook.file:
+            return Response({"error": "No file found for this e-book."}, status=status.HTTP_400_BAD_REQUEST)
+
+        download, created = DownloadRecord.objects.get_or_create(
+            user=request.user,
+            ebook=ebook,
+            defaults={"file_size": ebook.file.size if ebook.file else 0},
+        )
+        if not created:
+            download.file_size = ebook.file.size if ebook.file else 0
+            download.save(update_fields=["file_size"])
+
+        serializer = DownloadRecordSerializer(download, context={"request": request})
+        return Response(serializer.data, status=status.HTTP_200_OK)
+
+    @action(detail=False, methods=["get"])
+    def downloads(self, request: Request) -> Response:
+        """List all e-books the current user has downloaded."""
+        records = DownloadRecord.objects.filter(user=request.user).select_related(
+            "ebook", "ebook__reading_progress"
+        ).prefetch_related("ebook__chapters")
+        page = self.paginate_queryset(records)
+        if page is not None:
+            serializer = DownloadRecordSerializer(page, many=True, context={"request": request})
+            return self.get_paginated_response(serializer.data)
+        serializer = DownloadRecordSerializer(records, many=True, context={"request": request})
+        return Response(serializer.data)
+
+    @action(detail=False, methods=["delete"], url_path="downloads/(?P<download_pk>[^/.]+)")
+    def delete_download(self, request: Request, download_pk: str | None = None) -> Response:
+        """Delete a download record."""
+        try:
+            download = DownloadRecord.objects.get(pk=download_pk, user=request.user)
+        except DownloadRecord.DoesNotExist:
+            return Response({"error": "Download record not found."}, status=status.HTTP_404_NOT_FOUND)
+        download.delete()
+        return Response(status=status.HTTP_204_NO_CONTENT)
+
+
+def _store_chapters(ebook: EBook, toc: list[dict[str, Any]], parent_index: int = 0) -> None:
+    """Recursively store TOC entries as BookChapter records."""
+    for idx, entry in enumerate(toc):
+        BookChapter.objects.create(
+            ebook=ebook,
+            title=entry.get("title", "Untitled"),
+            index=parent_index + idx,
+            href=entry.get("href", ""),
+            children=entry.get("children", []),
+        )
+        children = entry.get("children", [])
+        if children:
+            _store_chapters(ebook, children, parent_index + idx + 1)
+
+
+def _fetch_chapter_content(ebook: EBook, chapter: BookChapter) -> str:
+    """Fetch HTML content for a chapter from the e-book file."""
+    if ebook.format == "epub":
+        return _fetch_epub_chapter_content(ebook.file.path, chapter)
+    return ""
+
+
+def _fetch_epub_chapter_content(file_path: str, chapter: BookChapter) -> str:
+    """Extract HTML content of a specific EPUB chapter by href."""
+    try:
+        from ebooklib import epub
+        from bs4 import BeautifulSoup
+    except ImportError:
+        return ""
+
+    try:
+        book = epub.read_epub(file_path)
+        href = chapter.href or ""
+        # Find the item by href
+        for item in book.get_items():
+            item_name = item.get_name() or ""
+            if href and (item_name.endswith(href) or href.endswith(item_name)):
+                content = item.get_content()
+                soup = BeautifulSoup(content, "html.parser")
+                # Clean up — remove body/html/head wrappers, keep inner content
+                body = soup.find("body")
+                if body:
+                    return str(body)
+                return str(soup)
+        return ""
+    except Exception:
+        logger.exception("Failed to fetch EPUB chapter content for %s", chapter.href)
+        return ""
+
+
+class ReadingSettingsViewSet(viewsets.GenericViewSet):
+    permission_classes = [IsAuthenticated]
+    serializer_class = ReadingSettingsSerializer
+
+    def get_queryset(self):
+        return ReadingSettings.objects.filter(user=self.request.user)
+
+    def list(self, request: Request) -> Response:
+        settings_obj, _created = ReadingSettings.objects.get_or_create(user=request.user)
+        serializer = self.get_serializer(settings_obj)
+        return Response(serializer.data)
+
+    def partial_update(self, request: Request) -> Response:
+        settings_obj, _created = ReadingSettings.objects.get_or_create(user=request.user)
+        serializer = self.get_serializer(settings_obj, data=request.data, partial=True)
+        serializer.is_valid(raise_exception=True)
+        serializer.save()
+        return Response(serializer.data)

backend/apps/reader/apps.py

@@ -0,0 +1,7 @@
+from django.apps import AppConfig
+
+
+class ReaderConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "apps.reader"
+    verbose_name = "Reader Settings"

backend/apps/reader/models.py

@@ -0,0 +1,53 @@
+from django.conf import settings
+from django.db import models
+
+
+class ReadingSettings(models.Model):
+    """Per-user reading preferences for the e-book reader view."""
+
+    THEME_CHOICES = [
+        ("sepia", "Sepia"),
+        ("dark", "Dark"),
+        ("light", "Light"),
+        ("paper", "Paper"),
+    ]
+
+    FONT_CHOICES = [
+        ("sans-serif", "Sans-serif"),
+        ("serif", "Serif"),
+        ("monospace", "Monospace"),
+    ]
+
+    ORIENTATION_CHOICES = [
+        ("auto", "Auto"),
+        ("portrait", "Portrait"),
+        ("landscape", "Landscape"),
+    ]
+
+    user = models.OneToOneField(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="reading_settings",
+        primary_key=True,
+    )
+    font_family = models.CharField(max_length=32, choices=FONT_CHOICES, default="serif")
+    font_size = models.PositiveSmallIntegerField(default=18)
+    line_height = models.FloatField(default=1.6)
+    margin_width = models.PositiveSmallIntegerField(default=16)
+    background_color = models.CharField(max_length=7, default="#f5f0eb")
+    text_color = models.CharField(max_length=7, default="#1a1a1a")
+    brightness = models.PositiveSmallIntegerField(default=100)
+    orientation_lock = models.CharField(
+        max_length=16, choices=ORIENTATION_CHOICES, default="auto"
+    )
+    theme = models.CharField(max_length=32, choices=THEME_CHOICES, default="sepia")
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "reader_reading_settings"
+        verbose_name = "Reading Settings"
+        verbose_name_plural = "Reading Settings"
+
+    def __str__(self) -> str:
+        return f"{self.user} — {self.theme} ({self.font_size}px)"

backend/apps/reader/serializers.py

@@ -0,0 +1,63 @@
+from rest_framework import serializers
+
+from apps.reader.models import ReadingSettings
+
+# Theme presets mapped to colors
+THEME_COLORS = {
+    "sepia": {"background_color": "#f5f0eb", "text_color": "#1a1a1a"},
+    "dark": {"background_color": "#1a1a2e", "text_color": "#e0e0e0"},
+    "light": {"background_color": "#ffffff", "text_color": "#1a1a1a"},
+    "paper": {"background_color": "#e8e0d4", "text_color": "#2c2c2c"},
+}
+
+
+class ReadingSettingsSerializer(serializers.ModelSerializer):
+    """Serialize ReadingSettings for the current user."""
+
+    class Meta:
+        model = ReadingSettings
+        fields = [
+            "font_family",
+            "font_size",
+            "line_height",
+            "margin_width",
+            "background_color",
+            "text_color",
+            "brightness",
+            "orientation_lock",
+            "theme",
+            "created_at",
+            "updated_at",
+        ]
+        read_only_fields = ["created_at", "updated_at"]
+
+    def validate_font_size(self, value: int) -> int:
+        if value < 12 or value > 32:
+            raise serializers.ValidationError("Font size must be between 12 and 32.")
+        return value
+
+    def validate_line_height(self, value: float) -> float:
+        if value < 1.2 or value > 2.0:
+            raise serializers.ValidationError("Line height must be between 1.2 and 2.0.")
+        return value
+
+    def validate_margin_width(self, value: int) -> int:
+        if value < 8 or value > 48:
+            raise serializers.ValidationError("Margin width must be between 8 and 48.")
+        return value
+
+    def validate_brightness(self, value: int) -> int:
+        if value < 0 or value > 100:
+            raise serializers.ValidationError("Brightness must be between 0 and 100.")
+        return value
+
+    def validate(self, attrs):
+        """Sync theme colors when theme changes, unless explicit colors provided."""
+        theme = attrs.get("theme")
+        if theme and theme in THEME_COLORS:
+            # Only auto-set colors if not explicitly provided
+            if "background_color" not in attrs:
+                attrs["background_color"] = THEME_COLORS[theme]["background_color"]
+            if "text_color" not in attrs:
+                attrs["text_color"] = THEME_COLORS[theme]["text_color"]
+        return attrs

backend/apps/reader/urls.py

@@ -0,0 +1,7 @@
+from django.urls import path
+
+from apps.reader.views import reading_settings_view
+
+urlpatterns = [
+    path("settings/", reading_settings_view, name="reading-settings"),
+]

backend/apps/reader/views.py

@@ -0,0 +1,33 @@
+from rest_framework import permissions, status
+from rest_framework.decorators import api_view, permission_classes
+from rest_framework.request import Request
+from rest_framework.response import Response
+
+from apps.reader.models import ReadingSettings
+from apps.reader.serializers import ReadingSettingsSerializer
+
+
+@api_view(["GET", "PUT", "PATCH"])
+@permission_classes([permissions.IsAuthenticated])
+def reading_settings_view(request: Request) -> Response:
+    """Get or update the current user's reading settings.
+
+    GET  → return existing settings (auto-create defaults if missing)
+    PUT  → create or fully replace settings
+    PATCH → partial update
+    """
+    user = request.user
+    settings, created = ReadingSettings.objects.get_or_create(user=user)
+
+    if request.method == "GET":
+        serializer = ReadingSettingsSerializer(settings)
+        return Response(serializer.data)
+
+    if request.method == "PUT":
+        serializer = ReadingSettingsSerializer(settings, data=request.data)
+    elif request.method == "PATCH":
+        serializer = ReadingSettingsSerializer(settings, data=request.data, partial=True)
+
+    serializer.is_valid(raise_exception=True)
+    serializer.save()
+    return Response(serializer.data, status=status.HTTP_200_OK)

backend/config/django.py

@@ -40,6 +40,7 @@ INSTALLED_APPS = [
     "apps.users",
     "apps.books",
     "apps.annotations",
+    "apps.reader",
 ]
 
 MIDDLEWARE = [

backend/config/urls.py

@@ -6,4 +6,5 @@ urlpatterns = [
     path("api/auth/", include("apps.users.urls")),
     path("api/books/", include("apps.books.urls")),
     path("api/annotations/", include("apps.annotations.urls")),
+    path("api/reader/", include("apps.reader.urls")),
 ]

docs/001-customizable-mobile-reading-experience.md

@@ -0,0 +1,246 @@
+# US: Customizable Mobile Reading Experience
+
+**Issue:** https://gitea-dev.codescripters.org/HermesFactory/cloud-reader/issues (TBD)
+
+## Overview
+
+Add a full-screen reading view for ebooks with customizable typography, themes,
+table of contents navigation, and orientation support. Mobile-first, responsive
+design that adapts to any screen size.
+
+---
+
+## Backend Specification
+
+### New Models
+
+#### `apps.books.models.Chapter`
+
+| Field        | Type               | Notes                          |
+|-------------|--------------------|--------------------------------|
+| id          | AutoField (PK)     |                                |
+| book        | FK -> Book         | related_name="chapters"        |
+| title       | CharField(512)     | Chapter title                  |
+| number      | PositiveIntegerField | Chapter ordering / TOC index |
+| content     | TextField          | Chapter text/markdown content  |
+| created_at  | DateTimeField      | auto_now_add                   |
+| updated_at  | DateTimeField      | auto_now                       |
+
+**Constraints:** UniqueConstraint(book, chapter_number)
+**Ordering:** [book, number]
+**Index:** FK to book with db_index
+
+#### `apps.books.models.ReadingProgress`
+
+| Field             | Type               | Notes                          |
+|------------------|--------------------|--------------------------------|
+| id               | AutoField (PK)     |                                |
+| user             | FK -> User         | related_name="reading_progress"|
+| book             | FK -> Book         | related_name="reading_progress"|
+| current_chapter  | PositiveIntegerField | Last chapter number          |
+| current_position | PositiveIntegerField | Position within chapter (paragraph) |
+| percentage       | FloatField         | 0.0 - 100.0 overall progress  |
+| updated_at       | DateTimeField      | auto_now                       |
+
+**Constraints:** UniqueConstraint(user, book)
+**Indexes:** (user, book) composite, (user) filter for list queries
+
+#### `apps.reader.models.ReadingSettings`
+
+New app `apps/reader/` for reading preferences, isolated from book data model.
+
+| Field              | Type               | Notes                         |
+|-------------------|--------------------|-------------------------------|
+| id                | AutoField (PK)     |                               |
+| user              | OneToOneField -> User | related_name="reading_settings" |
+| font_family       | CharField(32)      | "sans-serif", "serif", "monospace" |
+| font_size         | PositiveSmallIntegerField | 12-32, default 18       |
+| line_height       | FloatField         | 1.2 - 2.0, default 1.6       |
+| margin_width      | PositiveSmallIntegerField | 8-48, default 16 (px)   |
+| background_color  | CharField(7)       | Hex color, default "#f5f0eb" |
+| text_color        | CharField(7)       | Hex color, default "#1a1a1a" |
+| brightness        | PositiveSmallIntegerField | 0-100, default 100       |
+| orientation_lock  | CharField(16)      | "auto", "portrait", "landscape" |
+| theme             | CharField(32)      | "sepia", "dark", "light", "paper" |
+| created_at        | DateTimeField      | auto_now_add                  |
+| updated_at        | DateTimeField      | auto_now                      |
+
+### New API Endpoints
+
+All under `/api/` prefix, authenticated with JWT.
+
+#### Reader Settings (`/api/reader/settings/`)
+
+| Method | URL                          | Action                    |
+|--------|------------------------------|---------------------------|
+| GET    | /api/reader/settings/        | Get current user settings |
+| PUT    | /api/reader/settings/        | Create/update settings    |
+| PATCH  | /api/reader/settings/        | Partial update settings   |
+
+- Single-object endpoint (one settings record per user, auto-created on first GET)
+- Validation: font_size 12-32, line_height 1.2-2.0, margin_width 8-48
+
+#### Reading Progress (`/api/books/{id}/progress/`)
+
+| Method | URL                                    | Action                       |
+|--------|----------------------------------------|------------------------------|
+| GET    | /api/books/{id}/progress/              | Get reading progress for book|
+| PUT    | /api/books/{id}/progress/              | Create/update reading progress|
+
+- Nested under book detail
+- Auto-creates progress record on first PUT
+
+#### Chapters (`/api/books/{id}/chapters/`)
+
+| Method | URL                                    | Action                       |
+|--------|----------------------------------------|------------------------------|
+| GET    | /api/books/{id}/chapters/              | List chapters for book (TOC) |
+| GET    | /api/books/{id}/chapters/{number}/     | Get specific chapter content |
+
+- Ordering by `number`
+- Used by frontend TOC sidebar and content loading
+
+---
+
+## Frontend Specification
+
+### New Pages
+
+#### `/reader/:bookId` — ReadingPage
+
+Full-screen reading view with:
+- Chapter content display (left/right swiping or scroll)
+- Bottom toolbar: TOC toggle, Settings toggle, Progress indicator
+- Top bar: Back button, Book title, Chapter title
+- Swipe/tap/page navigation between chapters
+
+### New Components
+
+#### `ReaderToolbar`
+- Fixed bottom toolbar
+- TOC button (opens TOC drawer)
+- Settings/theme button (opens settings panel)
+- Progress bar showing overall reading progress
+
+#### `TableOfContents`
+- Slide-in drawer from left
+- Lists all chapters with current chapter highlighted
+- Tap on chapter to navigate
+- Shows reading progress per chapter
+
+#### `ReadingSettingsPanel`
+- Slide-in drawer from right (or bottom sheet on mobile)
+- Controls:
+  - Theme presets: Sepia, Dark, Light, Paper
+  - Font family: Sans-serif, Serif, Monospace
+  - Font size slider (12-32)
+  - Line height slider (1.2-2.0)
+  - Margin/padding control
+  - Orientation lock toggle (Auto / Portrait / Landscape)
+- All changes persist immediately via API
+- LocalStorage fallback when offline
+
+### New Hooks
+
+#### `useReadingSettings(bookId)`
+- Fetches user reading settings from API
+- Returns current settings + update function
+- Applies CSS custom properties to document root
+- Falls back to defaults if API unavailable
+
+#### `useChapters(bookId)`
+- Fetches chapter list for TOC
+- Returns chapters array, current chapter, navigate function
+- Prefetches next/prev chapter content
+
+#### `useReadingProgress(bookId)`
+- Fetches/updates reading progress
+- Auto-saves position on chapter change and periodic interval
+
+### New Types
+
+```typescript
+interface Chapter {
+  id: number;
+  book: number;
+  title: string;
+  number: number;
+  content?: string; // Only present when fetching individual chapter
+}
+
+interface ChapterSummary {
+  id: number;
+  book: number;
+  title: string;
+  number: number;
+}
+
+interface ReadingSettings {
+  font_family: "sans-serif" | "serif" | "monospace";
+  font_size: number;
+  line_height: number;
+  margin_width: number;
+  background_color: string;
+  text_color: string;
+  brightness: number;
+  orientation_lock: "auto" | "portrait" | "landscape";
+  theme: "sepia" | "dark" | "light" | "paper";
+}
+
+interface ReadingProgress {
+  current_chapter: number;
+  current_position: number;
+  percentage: number;
+  updated_at: string;
+}
+```
+
+### CSS / Theming
+
+Reading view uses CSS custom properties driven by reading settings:
+
+```css
+:root {
+  --reader-bg: var(--bg-color, #f5f0eb);
+  --reader-text: var(--text-color, #1a1a1a);
+  --reader-font-family: var(--font-family, "Georgia", serif);
+  --reader-font-size: var(--font-size, 18px);
+  --reader-line-height: var(--line-height, 1.6);
+  --reader-margin: var(--margin-width, 16px);
+}
+```
+
+Three theme presets:
+- **Sepia**: `bg:#f5f0eb`, `text:#1a1a1a` — warm, easy on eyes
+- **Dark**: `bg:#1a1a2e`, `text:#e0e0e0` — for low-light reading
+- **Light**: `bg:#ffffff`, `text:#1a1a1a` — crisp and clean
+- **Paper**: `bg:#e8e0d4`, `text:#2c2c2c` — book-like feel
+
+### Orientation Support
+
+- CSS `@media (orientation: portrait)` and `@media (orientation: landscape)` breakpoints
+- Reading settings panel includes orientation lock toggle
+- On mobile, landscape mode expands content horizontally with wider margins
+- Portrait mode stacks controls vertically for thumb-reachable UI
+
+### Routing
+
+Add to App.tsx:
+```
+/                     → LibraryPage
+/books/:bookId        → BookDetailPage
+/reader/:bookId       → ReadingPage
+```
+
+---
+
+## Implementation Order
+
+1. Backend models + migrations (Chapter, ReadingProgress, ReadingSettings)
+2. Backend serializers + views + URLs
+3. Frontend types + API client
+4. Frontend hooks (useReadingSettings, useChapters, useReadingProgress)
+5. Frontend components (ReadingSettingsPanel, TableOfContents, ReaderToolbar)
+6. Frontend page (ReadingPage)
+7. Routing updates
+8. CSS / theming

frontend/src/App.tsx

@@ -0,0 +1,62 @@
+import React, { lazy, Suspense, useState } from "react";
+import { BrowserRouter, Navigate, Route, Routes } from "react-router-dom";
+import { AuthProvider, useAuth } from "./context/AuthContext";
+
+const LibraryPage = lazy(() => import("./pages/Library").then((m) => ({ default: m.LibraryPage })));
+const BookDetailPage = lazy(() => import("./pages/BookDetailPage").then((m) => ({ default: m.BookDetailPage })));
+const ReaderPage = lazy(() => import("./pages/Reader").then((m) => ({ default: m.ReaderPage })));
+const AddBookPage = lazy(() => import("./pages/AddBook").then((m) => ({ default: m.AddBookPage })));
+const EditEBookPage = lazy(() => import("./pages/EditEBook").then((m) => ({ default: m.EditEBookPage })));
+const SettingsPage = lazy(() => import("./pages/Settings").then((m) => ({ default: m.SettingsPage })));
+const BookmarksNotesPage = lazy(() => import("./components/annotations/BookmarksNotesPage").then((m) => ({ default: m.BookmarksNotesPage })));
+const ReadingPage = lazy(() => import("./pages/ReadingPage").then((m) => ({ default: m.default })));
+
+const AuthPage = lazy(() =>
+  import("./pages/AuthPage").then((m) => ({
+    default: () => {
+      const [isLogin, setIsLogin] = useState(true);
+      return isLogin ? <m.LoginPage onToggle={() => setIsLogin(false)} /> : <m.RegisterPage onToggle={() => setIsLogin(true)} />;
+    },
+  })),
+);
+
+function LoadingFallback() {
+  return <div style={{ display: "flex", justifyContent: "center", alignItems: "center", minHeight: "100vh", color: "#888", fontSize: 16 }}><p>Loading...</p></div>;
+}
+
+function ProtectedRoute({ children }: { children: React.ReactNode }) {
+  const { isAuthenticated, loading } = useAuth();
+  if (loading) return <LoadingFallback />;
+  if (!isAuthenticated) return <Navigate to="/auth" replace />;
+  return <>{children}</>;
+}
+
+function AppRoutes() {
+  const { isAuthenticated } = useAuth();
+  return (
+    <Suspense fallback={<LoadingFallback />}>
+      <Routes>
+        <Route path="/auth" element={isAuthenticated ? <Navigate to="/" replace /> : <AuthPage />} />
+        <Route path="/" element={<ProtectedRoute><LibraryPage /></ProtectedRoute>} />
+        <Route path="/books/:id" element={<ProtectedRoute><BookDetailPage /></ProtectedRoute>} />
+        <Route path="/reader/:id" element={<ProtectedRoute><ReaderPage /></ProtectedRoute>} />
+        <Route path="/read/:id" element={<ProtectedRoute><ReadingPage /></ProtectedRoute>} />
+        <Route path="/add" element={<ProtectedRoute><AddBookPage /></ProtectedRoute>} />
+        <Route path="/edit/:id" element={<ProtectedRoute><EditEBookPage /></ProtectedRoute>} />
+        <Route path="/settings" element={<ProtectedRoute><SettingsPage /></ProtectedRoute>} />
+        <Route path="/bookmarks-notes/:bookId?" element={<ProtectedRoute><BookmarksNotesPage /></ProtectedRoute>} />
+        <Route path="*" element={<Navigate to="/" replace />} />
+      </Routes>
+    </Suspense>
+  );
+}
+
+export default function App() {
+  return (
+    <BrowserRouter>
+      <AuthProvider>
+        <AppRoutes />
+      </AuthProvider>
+    </BrowserRouter>
+  );
+}

frontend/src/api/reader.ts

@@ -0,0 +1,112 @@
+/**
+ * API client for the reader module — reading settings, chapters, and progress.
+ */
+
+import type {
+  ChapterDetail,
+  ChapterSummary,
+  ReadingProgress,
+  ReadingSettings,
+} from "../types/reader";
+
+const API_BASE = "/api";
+
+/**
+ * Fetch the current user's reading settings.
+ * Auto-creates defaults on the server if none exist.
+ */
+export async function getReadingSettings(): Promise<ReadingSettings> {
+  const response = await fetch(`${API_BASE}/reader/settings/`);
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch reading settings: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingSettings>;
+}
+
+/**
+ * Update (full or partial) the user's reading settings.
+ */
+export async function updateReadingSettings(
+  settings: Partial<ReadingSettings>
+): Promise<ReadingSettings> {
+  const method = settings.theme !== undefined ? "PUT" : "PATCH";
+  const response = await fetch(`${API_BASE}/reader/settings/`, {
+    method,
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(settings),
+  });
+  if (!response.ok) {
+    throw new Error(
+      `Failed to update reading settings: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingSettings>;
+}
+
+/**
+ * Fetch the table of contents (chapter list) for a book.
+ */
+export async function getChapters(bookId: number): Promise<ChapterSummary[]> {
+  const response = await fetch(`${API_BASE}/books/${bookId}/chapters/`);
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch chapters: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ChapterSummary[]>;
+}
+
+/**
+ * Fetch a specific chapter with full content for reading.
+ */
+export async function getChapterContent(
+  bookId: number,
+  chapterNumber: number
+): Promise<ChapterDetail> {
+  const response = await fetch(
+    `${API_BASE}/books/${bookId}/chapters/${chapterNumber}/`
+  );
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch chapter ${chapterNumber}: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ChapterDetail>;
+}
+
+/**
+ * Fetch reading progress for a book.
+ */
+export async function getReadingProgress(
+  bookId: number
+): Promise<ReadingProgress> {
+  const response = await fetch(`${API_BASE}/books/${bookId}/progress/`);
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch reading progress: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingProgress>;
+}
+
+/**
+ * Update reading progress for a book.
+ */
+export async function updateReadingProgress(
+  bookId: number,
+  progress: Partial<ReadingProgress>
+): Promise<ReadingProgress> {
+  const response = await fetch(`${API_BASE}/books/${bookId}/progress/`, {
+    method: "PUT",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(progress),
+  });
+  if (!response.ok) {
+    throw new Error(
+      `Failed to update reading progress: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingProgress>;
+}

frontend/src/components/reader/ReaderToolbar.tsx

@@ -0,0 +1,67 @@
+/**
+ * ReaderToolbar — fixed bottom toolbar for the reading view.
+ * Provides TOC toggle, settings toggle, and progress indicator.
+ */
+
+import type { ReadingProgress } from "../../types/reader";
+
+interface ReaderToolbarProps {
+  bookTitle: string;
+  chapterTitle: string;
+  progress: ReadingProgress | null;
+  onToggleToc: () => void;
+  onToggleSettings: () => void;
+}
+
+export default function ReaderToolbar({
+  bookTitle,
+  chapterTitle,
+  progress,
+  onToggleToc,
+  onToggleSettings,
+}: ReaderToolbarProps) {
+  const percentage = progress?.percentage ?? 0;
+
+  return (
+    <>
+      {/* Top bar */}
+      <header className="reader-top-bar">
+        <button
+          type="button"
+          className="reader-bar-btn"
+          onClick={onToggleToc}
+          aria-label="Table of contents"
+        >
+          <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+            <line x1="3" y1="6" x2="21" y2="6" />
+            <line x1="3" y1="12" x2="21" y2="12" />
+            <line x1="3" y1="18" x2="21" y2="18" />
+          </svg>
+        </button>
+        <div className="reader-bar-title">
+          <span className="reader-bar-book">{bookTitle}</span>
+          <span className="reader-bar-chapter">{chapterTitle}</span>
+        </div>
+        <button
+          type="button"
+          className="reader-bar-btn"
+          onClick={onToggleSettings}
+          aria-label="Reading settings"
+        >
+          <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+            <circle cx="12" cy="12" r="3" />
+            <path d="M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1 0 2.83 2 2 0 0 1-2.83 0l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-2 2 2 2 0 0 1-2-2v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83 0 2 2 0 0 1 0-2.83l.06-.06A1.65 1.65 0 0 0 4.68 15a1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1-2-2 2 2 0 0 1 2-2h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 0-2.83 2 2 0 0 1 2.83 0l.06.06A1.65 1.65 0 0 0 9 4.68a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 2-2 2 2 0 0 1 2 2v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 0 2 2 0 0 1 0 2.83l-.06.06a1.65 1.65 0 0 0-.33 1.82V9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 2 2 2 2 0 0 1-2 2h-.09a1.65 1.65 0 0 0-1.51 1z" />
+          </svg>
+        </button>
+      </header>
+
+      {/* Bottom progress bar */}
+      <div className="reader-progress-bar">
+        <div
+          className="reader-progress-fill"
+          style={{ width: `${Math.min(percentage, 100)}%` }}
+        />
+      </div>
+    </>
+  );
+}

frontend/src/components/reader/ReadingSettingsPanel.tsx

@@ -0,0 +1,232 @@
+/**
+ * ReadingSettingsPanel — slide-in drawer from the right for customizing
+ * the reading experience: theme, font, sizing, orientation.
+ */
+
+import { useState } from "react";
+import type {
+  FontFamily,
+  OrientationLock,
+  ReadingSettings,
+  ThemePreset,
+} from "../../types/reader";
+
+interface ReadingSettingsPanelProps {
+  settings: ReadingSettings;
+  isOpen: boolean;
+  onClose: () => void;
+  onUpdate: (partial: Partial<ReadingSettings>) => Promise<void>;
+}
+
+const THEME_OPTIONS: { value: ThemePreset; label: string }[] = [
+  { value: "sepia", label: "Sepia" },
+  { value: "dark", label: "Dark" },
+  { value: "light", label: "Light" },
+  { value: "paper", label: "Paper" },
+];
+
+const FONT_OPTIONS: { value: FontFamily; label: string }[] = [
+  { value: "sans-serif", label: "Sans-serif" },
+  { value: "serif", label: "Serif" },
+  { value: "monospace", label: "Monospace" },
+];
+
+const ORIENTATION_OPTIONS: { value: OrientationLock; label: string }[] = [
+  { value: "auto", label: "Auto" },
+  { value: "portrait", label: "Portrait" },
+  { value: "landscape", label: "Landscape" },
+];
+
+export default function ReadingSettingsPanel({
+  settings,
+  isOpen,
+  onClose,
+  onUpdate,
+}: ReadingSettingsPanelProps) {
+  const [saving, setSaving] = useState<Record<string, boolean>>({});
+
+  const handleChange = async (
+    key: keyof ReadingSettings,
+    value: string | number
+  ) => {
+    setSaving((prev) => ({ ...prev, [key]: true }));
+    try {
+      await onUpdate({ [key]: value as never });
+    } finally {
+      setSaving((prev) => ({ ...prev, [key]: false }));
+    }
+  };
+
+  return (
+    <>
+      {/* Overlay */}
+      {isOpen && (
+        <div
+          className="settings-overlay"
+          onClick={onClose}
+          onKeyDown={(e: React.KeyboardEvent) => {
+            if (e.key === "Escape") onClose();
+          }}
+          role="presentation"
+        />
+      )}
+
+      {/* Drawer */}
+      <aside
+        className={`settings-drawer ${isOpen ? "settings-drawer--open" : ""}`}
+      >
+        <div className="settings-header">
+          <h2 className="settings-title">Reading Settings</h2>
+          <button
+            type="button"
+            className="settings-close-btn"
+            onClick={onClose}
+            aria-label="Close settings"
+          >
+            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <line x1="18" y1="6" x2="6" y2="18" />
+              <line x1="6" y1="6" x2="18" y2="18" />
+            </svg>
+          </button>
+        </div>
+
+        <div className="settings-body">
+          {/* Theme Presets */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">Theme</h3>
+            <div className="theme-grid">
+              {THEME_OPTIONS.map((opt) => (
+                <button
+                  key={opt.value}
+                  type="button"
+                  className={`theme-btn ${
+                    settings.theme === opt.value ? "theme-btn--active" : ""
+                  }`}
+                  onClick={() => handleChange("theme", opt.value)}
+                  disabled={saving.theme}
+                >
+                  {opt.label}
+                </button>
+              ))}
+            </div>
+          </section>
+
+          {/* Font Family */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">Font</h3>
+            <div className="font-grid">
+              {FONT_OPTIONS.map((opt) => (
+                <button
+                  key={opt.value}
+                  type="button"
+                  className={`font-btn ${
+                    settings.font_family === opt.value ? "font-btn--active" : ""
+                  }`}
+                  onClick={() => handleChange("font_family", opt.value)}
+                  disabled={saving.font_family}
+                >
+                  {opt.label}
+                </button>
+              ))}
+            </div>
+          </section>
+
+          {/* Font Size Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Font Size: {settings.font_size}px
+            </h3>
+            <input
+              type="range"
+              min="12"
+              max="32"
+              value={settings.font_size}
+              onChange={(e) =>
+                handleChange("font_size", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Font size"
+            />
+          </section>
+
+          {/* Line Height Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Line Height: {settings.line_height.toFixed(1)}
+            </h3>
+            <input
+              type="range"
+              min="1.2"
+              max="2.0"
+              step="0.1"
+              value={settings.line_height}
+              onChange={(e) =>
+                handleChange("line_height", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Line height"
+            />
+          </section>
+
+          {/* Margin Width Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Margins: {settings.margin_width}px
+            </h3>
+            <input
+              type="range"
+              min="8"
+              max="48"
+              value={settings.margin_width}
+              onChange={(e) =>
+                handleChange("margin_width", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Margin width"
+            />
+          </section>
+
+          {/* Brightness Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Brightness: {settings.brightness}%
+            </h3>
+            <input
+              type="range"
+              min="0"
+              max="100"
+              value={settings.brightness}
+              onChange={(e) =>
+                handleChange("brightness", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Brightness"
+            />
+          </section>
+
+          {/* Orientation Lock */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">Orientation</h3>
+            <div className="orientation-grid">
+              {ORIENTATION_OPTIONS.map((opt) => (
+                <button
+                  key={opt.value}
+                  type="button"
+                  className={`orientation-btn ${
+                    settings.orientation_lock === opt.value
+                      ? "orientation-btn--active"
+                      : ""
+                  }`}
+                  onClick={() => handleChange("orientation_lock", opt.value)}
+                  disabled={saving.orientation_lock}
+                >
+                  {opt.label}
+                </button>
+              ))}
+            </div>
+          </section>
+        </div>
+      </aside>
+    </>
+  );
+}

frontend/src/components/reader/TableOfContents.tsx

@@ -0,0 +1,80 @@
+/**
+ * TableOfContents — slide-in drawer listing all chapters.
+ * Tap a chapter to navigate. Current chapter is highlighted.
+ */
+
+import type { ChapterSummary } from "../../types/reader";
+
+interface TableOfContentsProps {
+  chapters: ChapterSummary[];
+  currentChapterNumber: number;
+  isOpen: boolean;
+  onClose: () => void;
+  onNavigate: (number: number) => void;
+}
+
+export default function TableOfContents({
+  chapters,
+  currentChapterNumber,
+  isOpen,
+  onClose,
+  onNavigate,
+}: TableOfContentsProps) {
+  const handleChapterClick = (number: number) => {
+    onNavigate(number);
+    onClose();
+  };
+
+  return (
+    <>
+      {/* Overlay */}
+      {isOpen && (
+        <div
+          className="toc-overlay"
+          onClick={onClose}
+          onKeyDown={(e: React.KeyboardEvent) => {
+            if (e.key === "Escape") onClose();
+          }}
+          role="presentation"
+        />
+      )}
+
+      {/* Drawer */}
+      <aside className={`toc-drawer ${isOpen ? "toc-drawer--open" : ""}`}>
+        <div className="toc-header">
+          <h2 className="toc-title">Contents</h2>
+          <button
+            type="button"
+            className="toc-close-btn"
+            onClick={onClose}
+            aria-label="Close table of contents"
+          >
+            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <line x1="18" y1="6" x2="6" y2="18" />
+              <line x1="6" y1="6" x2="18" y2="18" />
+            </svg>
+          </button>
+        </div>
+
+        <nav className="toc-list">
+          {chapters.length === 0 && (
+            <p className="toc-empty">No chapters available.</p>
+          )}
+          {chapters.map((chapter) => (
+            <button
+              key={chapter.number}
+              type="button"
+              className={`toc-item ${
+                chapter.number === currentChapterNumber ? "toc-item--active" : ""
+              }`}
+              onClick={() => handleChapterClick(chapter.number)}
+            >
+              <span className="toc-item-number">{chapter.number}</span>
+              <span className="toc-item-title">{chapter.title}</span>
+            </button>
+          ))}
+        </nav>
+      </aside>
+    </>
+  );
+}

frontend/src/hooks/useChapters.ts

@@ -0,0 +1,129 @@
+/**
+ * useChapters — fetch chapter list and manage current chapter navigation.
+ */
+
+import { useCallback, useEffect, useState } from "react";
+import { getChapterContent, getChapters } from "../api/reader";
+import type { ChapterDetail, ChapterSummary } from "../types/reader";
+
+export interface UseChaptersReturn {
+  chapters: ChapterSummary[];
+  currentChapter: ChapterDetail | null;
+  currentChapterNumber: number;
+  isLoading: boolean;
+  error: string | null;
+  navigateToChapter: (number: number) => Promise<void>;
+  goToNextChapter: () => Promise<void>;
+  goToPreviousChapter: () => Promise<void>;
+  hasNext: boolean;
+  hasPrevious: boolean;
+}
+
+export function useChapters(
+  bookId: number,
+  initialChapter: number = 1
+): UseChaptersReturn {
+  const [chapters, setChapters] = useState<ChapterSummary[]>([]);
+  const [currentChapter, setCurrentChapter] = useState<ChapterDetail | null>(
+    null
+  );
+  const [currentChapterNumber, setCurrentChapterNumber] =
+    useState<number>(initialChapter);
+  const [isLoading, setIsLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  // Fetch chapter list on mount
+  useEffect(() => {
+    let cancelled = false;
+    setIsLoading(true);
+    getChapters(bookId)
+      .then((data) => {
+        if (!cancelled) {
+          setChapters(data);
+          // If chapters exist and initial chapter is valid, fetch it
+          if (
+            data.length > 0 &&
+            data.some((c) => c.number === currentChapterNumber)
+          ) {
+            return getChapterContent(bookId, currentChapterNumber);
+          }
+          return null;
+        }
+        return null;
+      })
+      .then((chapter) => {
+        if (!cancelled && chapter) {
+          setCurrentChapter(chapter);
+        }
+      })
+      .catch((err: unknown) => {
+        if (!cancelled) {
+          setError(
+            err instanceof Error ? err.message : "Failed to load chapters"
+          );
+        }
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [bookId, currentChapterNumber]);
+
+  const fetchChapter = useCallback(
+    async (number: number) => {
+      setIsLoading(true);
+      setError(null);
+      try {
+        const chapter = await getChapterContent(bookId, number);
+        setCurrentChapter(chapter);
+        setCurrentChapterNumber(number);
+      } catch (err: unknown) {
+        setError(
+          err instanceof Error ? err.message : "Failed to load chapter"
+        );
+      } finally {
+        setIsLoading(false);
+      }
+    },
+    [bookId]
+  );
+
+  const navigateToChapter = useCallback(
+    (number: number) => {
+      fetchChapter(number);
+    },
+    [fetchChapter]
+  );
+
+  const goToNextChapter = useCallback(() => {
+    const next = currentChapterNumber + 1;
+    if (chapters.some((c) => c.number === next)) {
+      fetchChapter(next);
+    }
+  }, [currentChapterNumber, chapters, fetchChapter]);
+
+  const goToPreviousChapter = useCallback(() => {
+    const prev = currentChapterNumber - 1;
+    if (prev >= 1 && chapters.some((c) => c.number === prev)) {
+      fetchChapter(prev);
+    }
+  }, [currentChapterNumber, chapters, fetchChapter]);
+
+  const hasNext = chapters.some((c) => c.number === currentChapterNumber + 1);
+  const hasPrevious = chapters.some((c) => c.number === currentChapterNumber - 1);
+
+  return {
+    chapters,
+    currentChapter,
+    currentChapterNumber,
+    isLoading,
+    error,
+    navigateToChapter,
+    goToNextChapter,
+    goToPreviousChapter,
+    hasNext,
+    hasPrevious,
+  };
+}

frontend/src/hooks/useReadingProgress.ts

@@ -0,0 +1,99 @@
+/**
+ * useReadingProgress — fetch and update reading progress for a book.
+ * Auto-saves when chapter or position changes.
+ */
+
+import { useCallback, useEffect, useRef, useState } from "react";
+import { getReadingProgress, updateReadingProgress } from "../api/reader";
+import type { ReadingProgress } from "../types/reader";
+
+export interface UseReadingProgressReturn {
+  progress: ReadingProgress | null;
+  isLoading: boolean;
+  error: string | null;
+  saveProgress: (
+    chapter: number,
+    position: number,
+    percentage: number
+  ) => Promise<void>;
+  /** Schedule a debounced save — fires at most once per 3 seconds */
+  debouncedSave: (
+    chapter: number,
+    position: number,
+    percentage: number
+  ) => void;
+}
+
+export function useReadingProgress(
+  bookId: number
+): UseReadingProgressReturn {
+  const [progress, setProgress] = useState<ReadingProgress | null>(null);
+  const [isLoading, setIsLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const debounceTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  // Fetch progress on mount
+  useEffect(() => {
+    let cancelled = false;
+    setIsLoading(true);
+    getReadingProgress(bookId)
+      .then((data) => {
+        if (!cancelled) setProgress(data);
+      })
+      .catch((err: unknown) => {
+        if (!cancelled) {
+          setError(
+            err instanceof Error ? err.message : "Failed to load progress"
+          );
+        }
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [bookId]);
+
+  const saveProgress = useCallback(
+    async (chapter: number, position: number, percentage: number) => {
+      try {
+        const updated = await updateReadingProgress(bookId, {
+          current_chapter: chapter,
+          current_position: position,
+          percentage,
+        });
+        setProgress(updated);
+        setError(null);
+      } catch (err: unknown) {
+        setError(
+          err instanceof Error ? err.message : "Failed to save progress"
+        );
+      }
+    },
+    [bookId]
+  );
+
+  const debouncedSave = useCallback(
+    (chapter: number, position: number, percentage: number) => {
+      if (debounceTimer.current) {
+        clearTimeout(debounceTimer.current);
+      }
+      debounceTimer.current = setTimeout(() => {
+        saveProgress(chapter, position, percentage);
+      }, 3000);
+    },
+    [saveProgress]
+  );
+
+  // Cleanup timer on unmount
+  useEffect(() => {
+    return () => {
+      if (debounceTimer.current) {
+        clearTimeout(debounceTimer.current);
+      }
+    };
+  }, []);
+
+  return { progress, isLoading, error, saveProgress, debouncedSave };
+}

frontend/src/hooks/useReadingSettings.ts

@@ -0,0 +1,96 @@
+/**
+ * useReadingSettings — fetch and manage user reading preferences.
+ * Applies settings as CSS custom properties on the document root.
+ */
+
+import { useCallback, useEffect, useState } from "react";
+import {
+  getReadingSettings,
+  updateReadingSettings,
+} from "../api/reader";
+import type { ReadingSettings } from "../types/reader";
+
+const DEFAULT_SETTINGS: ReadingSettings = {
+  font_family: "serif",
+  font_size: 18,
+  line_height: 1.6,
+  margin_width: 16,
+  background_color: "#f5f0eb",
+  text_color: "#1a1a1a",
+  brightness: 100,
+  orientation_lock: "auto",
+  theme: "sepia",
+  created_at: "",
+  updated_at: "",
+};
+
+function applyCssVariables(settings: ReadingSettings): void {
+  const root = document.documentElement;
+  root.style.setProperty("--reader-bg", settings.background_color);
+  root.style.setProperty("--reader-text", settings.text_color);
+  root.style.setProperty("--reader-font-family", settings.font_family);
+  root.style.setProperty("--reader-font-size", `${settings.font_size}px`);
+  root.style.setProperty("--reader-line-height", String(settings.line_height));
+  root.style.setProperty("--reader-margin", `${settings.margin_width}px`);
+  root.style.setProperty("--reader-brightness", `${settings.brightness}%`);
+}
+
+export interface UseReadingSettingsReturn {
+  settings: ReadingSettings;
+  isLoading: boolean;
+  error: string | null;
+  updateSettings: (partial: Partial<ReadingSettings>) => Promise<void>;
+}
+
+export function useReadingSettings(): UseReadingSettingsReturn {
+  const [settings, setSettings] = useState<ReadingSettings>(DEFAULT_SETTINGS);
+  const [isLoading, setIsLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  // Fetch settings on mount
+  useEffect(() => {
+    let cancelled = false;
+    setIsLoading(true);
+    getReadingSettings()
+      .then((data) => {
+        if (!cancelled) {
+          setSettings(data);
+          applyCssVariables(data);
+        }
+      })
+      .catch((err: unknown) => {
+        if (!cancelled) {
+          setError(
+            err instanceof Error ? err.message : "Failed to load reading settings"
+          );
+          // Apply defaults
+          applyCssVariables(DEFAULT_SETTINGS);
+        }
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  const updateSettings = useCallback(
+    async (partial: Partial<ReadingSettings>) => {
+      try {
+        const updated = await updateReadingSettings(partial);
+        setSettings(updated);
+        applyCssVariables(updated);
+        setError(null);
+      } catch (err: unknown) {
+        setError(
+          err instanceof Error ? err.message : "Failed to update reading settings"
+        );
+        throw err;
+      }
+    },
+    []
+  );
+
+  return { settings, isLoading, error, updateSettings };
+}

frontend/src/pages/ReadingPage.tsx

@@ -0,0 +1,213 @@
+/**
+ * ReadingPage — full-screen reading view for ebooks.
+ * Integrates TOC drawer, settings panel, chapter navigation, and progress tracking.
+ */
+
+import { lazy, Suspense, useCallback, useEffect, useState } from "react";
+import { useNavigate, useParams } from "react-router-dom";
+import { useChapters } from "../hooks/useChapters";
+import { useReadingProgress } from "../hooks/useReadingProgress";
+import { useReadingSettings } from "../hooks/useReadingSettings";
+import { booksApi } from "../api/books";
+import type { BookDetail } from "../types/book";
+import "../reader.css";
+
+const ReaderToolbar = lazy(() => import("../components/reader/ReaderToolbar"));
+const TableOfContents = lazy(() => import("../components/reader/TableOfContents"));
+const ReadingSettingsPanel = lazy(
+  () => import("../components/reader/ReadingSettingsPanel")
+);
+
+export default function ReadingPage() {
+  const { id } = useParams<{ id: string }>();
+  const navigate = useNavigate();
+  const bookId = Number(id);
+  const [book, setBook] = useState<BookDetail | null>(null);
+  const [bookLoading, setBookLoading] = useState(true);
+
+  // Fetch book details
+  useEffect(() => {
+    if (!bookId || Number.isNaN(bookId)) return;
+    setBookLoading(true);
+    booksApi.getBook(bookId)
+      .then(setBook)
+      .catch(() => { /* handled by useChapters error */ })
+      .finally(() => setBookLoading(false));
+  }, [bookId]);
+
+  const [tocOpen, setTocOpen] = useState(false);
+  const [settingsOpen, setSettingsOpen] = useState(false);
+
+  const { settings, updateSettings } = useReadingSettings();
+  const {
+    chapters,
+    currentChapter,
+    currentChapterNumber,
+    isLoading,
+    error,
+    navigateToChapter,
+    goToNextChapter,
+    goToPreviousChapter,
+    hasNext,
+    hasPrevious,
+  } = useChapters(bookId, 1);
+
+  const { progress, debouncedSave } = useReadingProgress(bookId);
+
+  // Auto-save progress when chapter changes
+  useEffect(() => {
+    if (currentChapter && currentChapterNumber > 0) {
+      debouncedSave(currentChapterNumber, 0, (currentChapterNumber / Math.max(chapters.length, 1)) * 100);
+    }
+  }, [currentChapterNumber, currentChapter?.id]);
+
+  const handleKeyDown = useCallback(
+    (e: KeyboardEvent) => {
+      if (e.key === "ArrowLeft" && hasPrevious) {
+        goToPreviousChapter();
+      } else if (e.key === "ArrowRight" && hasNext) {
+        goToNextChapter();
+      } else if (e.key === "Escape") {
+        setTocOpen(false);
+        setSettingsOpen(false);
+      }
+    },
+    [hasNext, hasPrevious, goToNextChapter, goToPreviousChapter]
+  );
+
+  useEffect(() => {
+    document.addEventListener("keydown", handleKeyDown);
+    return () => document.removeEventListener("keydown", handleKeyDown);
+  }, [handleKeyDown]);
+
+  // Lock/unlock orientation via CSS
+  useEffect(() => {
+    const root = document.documentElement;
+    if (settings.orientation_lock !== "auto") {
+      root.style.setProperty(
+        "--reader-orientation",
+        settings.orientation_lock === "portrait" ? "portrait" : "landscape"
+      );
+    } else {
+      root.style.removeProperty("--reader-orientation");
+    }
+  }, [settings.orientation_lock]);
+
+  // Show loading state
+  if (bookLoading || (isLoading && !currentChapter)) {
+    return (
+      <div className="reader-loading">
+        <div className="spinner" />
+        <p>Loading reader...</p>
+      </div>
+    );
+  }
+
+  if (error) {
+    return (
+      <div className="reader-loading">
+        <p className="reader-error">{error}</p>
+        <button type="button" className="back-button" onClick={() => navigate(`/books/${bookId}`)}>
+          Back to book
+        </button>
+      </div>
+    );
+  }
+
+  return (
+    <Suspense
+      fallback={
+        <div className="reader-loading">
+          <div className="spinner" />
+        </div>
+      }
+    >
+      <div className="reader-container">
+        <ReaderToolbar
+          bookTitle={book.title}
+          chapterTitle={currentChapter?.title ?? "Loading..."}
+          progress={progress}
+          onToggleToc={() => setTocOpen((v) => !v)}
+          onToggleSettings={() => setSettingsOpen((v) => !v)}
+        />
+
+        <TableOfContents
+          chapters={chapters}
+          currentChapterNumber={currentChapterNumber}
+          isOpen={tocOpen}
+          onClose={() => setTocOpen(false)}
+          onNavigate={navigateToChapter}
+        />
+
+        <ReadingSettingsPanel
+          settings={settings}
+          isOpen={settingsOpen}
+          onClose={() => setSettingsOpen(false)}
+          onUpdate={updateSettings}
+        />
+
+        {/* Main reading area */}
+        <main className="reader-content">
+          {isLoading ? (
+            <div className="reader-loading">
+              <div className="spinner" />
+              <p>Loading chapter...</p>
+            </div>
+          ) : currentChapter ? (
+            <article className="reader-chapter">
+              <h1 className="reader-chapter-title">{currentChapter.title}</h1>
+              <div
+                className="reader-chapter-body"
+                dangerouslySetInnerHTML={{
+                  __html: currentChapter.content,
+                }}
+              />
+            </article>
+          ) : (
+            <div className="reader-loading">
+              <p>Select a chapter from the table of contents to start reading.</p>
+            </div>
+          )}
+        </main>
+
+        {/* Bottom navigation bar */}
+        <nav className="reader-nav">
+          <button
+            type="button"
+            className={`reader-nav-btn ${!hasPrevious ? "reader-nav-btn--disabled" : ""}`}
+            onClick={goToPreviousChapter}
+            disabled={!hasPrevious}
+          >
+            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <polyline points="15 18 9 12 15 6" />
+            </svg>
+            Previous
+          </button>
+
+          <button
+            type="button"
+            className="reader-nav-btn reader-nav-btn--back"
+            onClick={() => navigate("/")}
+          >
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <path d="M20 12H4M10 18l-6-6 6-6" />
+            </svg>
+            Library
+          </button>
+
+          <button
+            type="button"
+            className={`reader-nav-btn ${!hasNext ? "reader-nav-btn--disabled" : ""}`}
+            onClick={goToNextChapter}
+            disabled={!hasNext}
+          >
+            Next
+            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <polyline points="9 18 15 12 9 6" />
+            </svg>
+          </button>
+        </nav>
+      </div>
+    </Suspense>
+  );
+}

frontend/src/reader.css

@@ -0,0 +1,621 @@
+/* ============================================================
+   Cloud Reader — Reading View Styles
+   Mobile-first reading experience with theme support
+   ============================================================ */
+
+/* --- CSS Custom Properties (overridden by JS) --- */
+:root {
+  --reader-bg: #f5f0eb;
+  --reader-text: #1a1a1a;
+  --reader-font-family: Georgia, "Times New Roman", serif;
+  --reader-font-size: 18px;
+  --reader-line-height: 1.6;
+  --reader-margin: 16px;
+  --reader-brightness: 100%;
+  --reader-toolbar-bg: rgba(26, 26, 26, 0.95);
+  --reader-toolbar-text: #e0e0e0;
+  --reader-accent: #6c8cff;
+}
+
+/* --- Reading Container --- */
+.reader-container {
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background: var(--reader-bg);
+  color: var(--reader-text);
+  font-family: var(--reader-font-family);
+  font-size: var(--reader-font-size);
+  line-height: var(--reader-line-height);
+  filter: brightness(var(--reader-brightness));
+  display: flex;
+  flex-direction: column;
+  z-index: 100;
+  overflow: hidden;
+}
+
+/* Orientation lock */
+@supports (--reader-orientation: portrait) {
+  .reader-container {
+    orientation: var(--reader-orientation);
+  }
+}
+
+@media (orientation: landascape) {
+  .reader-container {
+    --reader-margin: 24px;
+  }
+}
+
+/* --- Top Toolbar --- */
+.reader-top-bar {
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  height: 52px;
+  background: var(--reader-toolbar-bg);
+  color: var(--reader-toolbar-text);
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0 12px;
+  z-index: 120;
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+}
+
+.reader-bar-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 40px;
+  height: 40px;
+  background: transparent;
+  border: none;
+  color: var(--reader-toolbar-text);
+  cursor: pointer;
+  border-radius: 8px;
+  transition: background 0.15s;
+}
+
+.reader-bar-btn:hover {
+  background: rgba(255, 255, 255, 0.1);
+}
+
+.reader-bar-title {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 1px;
+  min-width: 0;
+  flex: 1;
+  padding: 0 8px;
+}
+
+.reader-bar-book {
+  font-size: 0.8rem;
+  font-weight: 600;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  max-width: 200px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+.reader-bar-chapter {
+  font-size: 0.7rem;
+  opacity: 0.7;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  max-width: 200px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+/* --- Progress Bar --- */
+.reader-progress-bar {
+  position: fixed;
+  top: 52px;
+  left: 0;
+  right: 0;
+  height: 3px;
+  background: rgba(255, 255, 255, 0.1);
+  z-index: 120;
+}
+
+.reader-progress-fill {
+  height: 100%;
+  background: var(--reader-accent);
+  transition: width 0.3s ease;
+}
+
+/* --- Main Content Area --- */
+.reader-content {
+  flex: 1;
+  overflow-y: auto;
+  padding: 72px var(--reader-margin) 72px;
+  -webkit-overflow-scrolling: touch;
+  scroll-behavior: smooth;
+}
+
+/* --- Chapter Article --- */
+.reader-chapter {
+  max-width: 680px;
+  margin: 0 auto;
+}
+
+.reader-chapter-title {
+  font-size: 1.6em;
+  font-weight: 700;
+  line-height: 1.3;
+  margin-bottom: 0.75em;
+  padding-bottom: 0.5em;
+  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
+  color: var(--reader-text);
+}
+
+/* Chapter body — content from API (could be HTML/markdown-rendered) */
+.reader-chapter-body {
+  font-size: 1em;
+  line-height: var(--reader-line-height);
+}
+
+.reader-chapter-body p {
+  margin-bottom: 1.2em;
+  text-align: justify;
+  hyphens: auto;
+}
+
+.reader-chapter-body h2,
+.reader-chapter-body h3,
+.reader-chapter-body h4 {
+  margin-top: 1.5em;
+  margin-bottom: 0.6em;
+  line-height: 1.3;
+}
+
+.reader-chapter-body blockquote {
+  border-left: 3px solid var(--reader-accent);
+  padding-left: 1em;
+  margin: 1em 0;
+  opacity: 0.85;
+  font-style: italic;
+}
+
+.reader-chapter-body img {
+  max-width: 100%;
+  height: auto;
+  border-radius: 4px;
+  margin: 1em 0;
+}
+
+.reader-chapter-body ul,
+.reader-chapter-body ol {
+  padding-left: 1.5em;
+  margin-bottom: 1.2em;
+}
+
+.reader-chapter-body li {
+  margin-bottom: 0.4em;
+}
+
+/* --- Navigation Bar (Bottom) --- */
+.reader-nav {
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  height: 56px;
+  background: var(--reader-toolbar-bg);
+  color: var(--reader-toolbar-text);
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0 12px;
+  z-index: 120;
+  gap: 8px;
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+}
+
+.reader-nav-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 14px;
+  background: transparent;
+  border: 1px solid rgba(255, 255, 255, 0.2);
+  border-radius: 8px;
+  color: var(--reader-toolbar-text);
+  font-size: 0.85rem;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+  cursor: pointer;
+  transition: all 0.15s;
+}
+
+.reader-nav-btn:hover:not(.reader-nav-btn--disabled) {
+  border-color: var(--reader-accent);
+  color: var(--reader-accent);
+}
+
+.reader-nav-btn--disabled {
+  opacity: 0.3;
+  cursor: not-allowed;
+}
+
+.reader-nav-btn--back {
+  background: rgba(108, 140, 255, 0.15);
+  border-color: rgba(108, 140, 255, 0.3);
+}
+
+.reader-nav-btn--back:hover {
+  background: rgba(108, 140, 255, 0.25);
+  color: var(--reader-accent);
+}
+
+/* --- TOC Drawer --- */
+.toc-overlay,
+.settings-overlay {
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background: rgba(0, 0, 0, 0.5);
+  z-index: 130;
+  animation: fadeIn 0.2s ease;
+}
+
+@keyframes fadeIn {
+  from { opacity: 0; }
+  to { opacity: 1; }
+}
+
+.toc-drawer,
+.settings-drawer {
+  position: fixed;
+  top: 0;
+  bottom: 0;
+  width: 300px;
+  max-width: 85vw;
+  background: var(--reader-toolbar-bg);
+  color: var(--reader-toolbar-text);
+  z-index: 140;
+  display: flex;
+  flex-direction: column;
+  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.toc-drawer {
+  left: 0;
+  transform: translateX(-100%);
+}
+
+.toc-drawer--open {
+  transform: translateX(0);
+}
+
+.settings-drawer {
+  right: 0;
+  transform: translateX(100%);
+}
+
+.settings-drawer--open {
+  transform: translateX(0);
+}
+
+.toc-header,
+.settings-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 16px;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
+}
+
+.toc-title,
+.settings-title {
+  font-size: 1.1rem;
+  font-weight: 700;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+.toc-close-btn,
+.settings-close-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 32px;
+  height: 32px;
+  background: transparent;
+  border: none;
+  color: var(--reader-toolbar-text);
+  cursor: pointer;
+  border-radius: 6px;
+  transition: background 0.15s;
+}
+
+.toc-close-btn:hover,
+.settings-close-btn:hover {
+  background: rgba(255, 255, 255, 0.1);
+}
+
+/* --- TOC List --- */
+.toc-list {
+  flex: 1;
+  overflow-y: auto;
+  padding: 8px 0;
+}
+
+.toc-empty {
+  padding: 24px 16px;
+  text-align: center;
+  opacity: 0.6;
+  font-size: 0.9rem;
+}
+
+.toc-item {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  width: 100%;
+  padding: 10px 16px;
+  background: transparent;
+  border: none;
+  color: var(--reader-toolbar-text);
+  font-size: 0.9rem;
+  text-align: left;
+  cursor: pointer;
+  transition: background 0.15s;
+  font-family: inherit;
+}
+
+.toc-item:hover {
+  background: rgba(255, 255, 255, 0.08);
+}
+
+.toc-item--active {
+  background: rgba(108, 140, 255, 0.15);
+  color: var(--reader-accent);
+  font-weight: 600;
+}
+
+.toc-item-number {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  min-width: 24px;
+  height: 24px;
+  font-size: 0.75rem;
+  font-weight: 700;
+  border-radius: 4px;
+  background: rgba(255, 255, 255, 0.1);
+  padding: 0 4px;
+}
+
+.toc-item-title {
+  flex: 1;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+/* --- Settings Panel --- */
+.settings-body {
+  flex: 1;
+  overflow-y: auto;
+  padding: 12px 16px 32px;
+}
+
+.settings-section {
+  margin-bottom: 20px;
+}
+
+.settings-section-title {
+  font-size: 0.75rem;
+  font-weight: 700;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: rgba(255, 255, 255, 0.5);
+  margin-bottom: 8px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+/* Theme grid */
+.theme-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 8px;
+}
+
+.theme-btn {
+  padding: 10px;
+  border: 1px solid rgba(255, 255, 255, 0.15);
+  border-radius: 8px;
+  background: transparent;
+  color: var(--reader-toolbar-text);
+  font-size: 0.85rem;
+  cursor: pointer;
+  transition: all 0.15s;
+  font-family: inherit;
+}
+
+.theme-btn:hover {
+  border-color: rgba(255, 255, 255, 0.3);
+}
+
+.theme-btn--active {
+  border-color: var(--reader-accent);
+  background: rgba(108, 140, 255, 0.15);
+  color: var(--reader-accent);
+  font-weight: 600;
+}
+
+/* Font grid */
+.font-grid,
+.orientation-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr 1fr;
+  gap: 8px;
+}
+
+.font-btn,
+.orientation-btn {
+  padding: 10px 8px;
+  border: 1px solid rgba(255, 255, 255, 0.15);
+  border-radius: 8px;
+  background: transparent;
+  color: var(--reader-toolbar-text);
+  font-size: 0.85rem;
+  cursor: pointer;
+  transition: all 0.15s;
+  font-family: inherit;
+}
+
+.font-btn:hover,
+.orientation-btn:hover {
+  border-color: rgba(255, 255, 255, 0.3);
+}
+
+.font-btn--active,
+.orientation-btn--active {
+  border-color: var(--reader-accent);
+  background: rgba(108, 140, 255, 0.15);
+  color: var(--reader-accent);
+  font-weight: 600;
+}
+
+/* Sliders */
+.settings-slider {
+  width: 100%;
+  height: 6px;
+  -webkit-appearance: none;
+  appearance: none;
+  background: rgba(255, 255, 255, 0.2);
+  border-radius: 3px;
+  outline: none;
+  cursor: pointer;
+}
+
+.settings-slider::-webkit-slider-thumb {
+  -webkit-appearance: none;
+  width: 20px;
+  height: 20px;
+  border-radius: 50%;
+  background: var(--reader-accent);
+  border: 2px solid white;
+  cursor: pointer;
+  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
+}
+
+.settings-slider::-moz-range-thumb {
+  width: 20px;
+  height: 20px;
+  border-radius: 50%;
+  background: var(--reader-accent);
+  border: 2px solid white;
+  cursor: pointer;
+}
+
+/* --- Start Reading Button (in book detail) --- */
+.start-reading-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  padding: 12px 24px;
+  background: var(--reader-accent);
+  border: none;
+  border-radius: 8px;
+  color: white;
+  font-size: 1rem;
+  font-weight: 600;
+  cursor: pointer;
+  transition: all 0.2s;
+  margin-top: 16px;
+  margin-bottom: 16px;
+  font-family: inherit;
+}
+
+.start-reading-btn:hover {
+  background: #5a7ae8;
+  transform: translateY(-1px);
+  box-shadow: 0 4px 12px rgba(108, 140, 255, 0.3);
+}
+
+/* --- Loading State --- */
+.reader-loading {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 12px;
+  padding: 48px;
+  color: var(--reader-text);
+}
+
+.reader-error {
+  color: #ef4444;
+  text-align: center;
+}
+
+/* --- Responsive --- */
+@media (max-width: 480px) {
+  .reader-chapter {
+    max-width: 100%;
+  }
+
+  .reader-nav-btn {
+    padding: 8px 10px;
+    font-size: 0.8rem;
+  }
+
+  .reader-nav-btn span {
+    display: none;
+  }
+
+  .toc-drawer,
+  .settings-drawer {
+    max-width: 100vw;
+  }
+
+  .reader-chapter-title {
+    font-size: 1.3em;
+  }
+}
+
+@media (min-width: 768px) {
+  .reader-chapter {
+    max-width: 720px;
+  }
+
+  .reader-chapter-body {
+    font-size: 1.05em;
+  }
+}
+
+/* --- Landscape on Mobile --- */
+@media (orientation: landscape) and (max-height: 500px) {
+  .reader-top-bar {
+    height: 44px;
+  }
+
+  .reader-content {
+    padding-top: 60px;
+    padding-bottom: 60px;
+  }
+
+  .reader-chapter-title {
+    font-size: 1.2em;
+  }
+}
+
+/* --- Dark mode theme override when reader uses light theme but system is dark --- */
+@media (prefers-color-scheme: dark) {
+  .reader-container[data-theme="light"] {
+    --reader-toolbar-bg: rgba(255, 255, 255, 0.95);
+    --reader-toolbar-text: #1a1a1a;
+  }
+}

frontend/src/types/reader.ts

@@ -0,0 +1,44 @@
+/**
+ * TypeScript interfaces for the Cloud Reader reader module.
+ * Reading view, settings, chapters, and progress types.
+ */
+
+export interface ChapterSummary {
+  id: number;
+  book: number;
+  title: string;
+  number: number;
+}
+
+export interface ChapterDetail extends ChapterSummary {
+  content: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface ReadingSettings {
+  font_family: "sans-serif" | "serif" | "monospace";
+  font_size: number;
+  line_height: number;
+  margin_width: number;
+  background_color: string;
+  text_color: string;
+  brightness: number;
+  orientation_lock: "auto" | "portrait" | "landscape";
+  theme: "sepia" | "dark" | "light" | "paper";
+  created_at: string;
+  updated_at: string;
+}
+
+export type ThemePreset = ReadingSettings["theme"];
+export type FontFamily = ReadingSettings["font_family"];
+export type OrientationLock = ReadingSettings["orientation_lock"];
+
+export interface ReadingProgress {
+  id: number;
+  book: number;
+  current_chapter: number;
+  current_position: number;
+  percentage: number;
+  updated_at: string;
+}

web/src/App.tsx

@@ -1,16 +1,19 @@
 /**
- * App — root component with simple page navigation (library ↔ book detail).
+ * App — root component with page navigation (library ↔ book detail ↔ reading view).
  */
 
 import { useState, lazy, Suspense } from "react";
 import "./App.css";
+import "./reader.css";
 
 const LibraryPage = lazy(() => import("./pages/LibraryPage"));
 const BookDetailPage = lazy(() => import("./pages/BookDetailPage"));
+const ReadingPage = lazy(() => import("./pages/ReadingPage"));
 
 type View =
   | { kind: "library" }
-  | { kind: "detail"; bookId: number };
+  | { kind: "detail"; bookId: number }
+  | { kind: "reader"; book: import("./types").BookDetail };
 
 function LoadingFallback() {
   return (
@@ -32,13 +35,25 @@ export default function App() {
     setView({ kind: "library" });
   };
 
+  const handleStartReading = (book: import("./types").BookDetail) => {
+    setView({ kind: "reader", book });
+  };
+
   return (
     <div className="app">
       <Suspense fallback={<LoadingFallback />}>
-        {view.kind === "library" ? (
+        {view.kind === "library" && (
           <LibraryPage onBookSelect={handleBookSelect} />
-        ) : (
-          <BookDetailPage bookId={view.bookId} onBack={handleBack} />
+        )}
+        {view.kind === "detail" && view.bookId !== undefined && (
+          <BookDetailPage
+            bookId={view.bookId}
+            onBack={handleBack}
+            onStartReading={handleStartReading}
+          />
+        )}
+        {view.kind === "reader" && view.book !== undefined && (
+          <ReadingPage book={view.book} onBack={handleBack} />
         )}
       </Suspense>
     </div>

web/src/api/reader.ts

@@ -0,0 +1,112 @@
+/**
+ * API client for the reader module — reading settings, chapters, and progress.
+ */
+
+import type {
+  ChapterDetail,
+  ChapterSummary,
+  ReadingProgress,
+  ReadingSettings,
+} from "../types/reader";
+
+const API_BASE = "/api";
+
+/**
+ * Fetch the current user's reading settings.
+ * Auto-creates defaults on the server if none exist.
+ */
+export async function getReadingSettings(): Promise<ReadingSettings> {
+  const response = await fetch(`${API_BASE}/reader/settings/`);
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch reading settings: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingSettings>;
+}
+
+/**
+ * Update (full or partial) the user's reading settings.
+ */
+export async function updateReadingSettings(
+  settings: Partial<ReadingSettings>
+): Promise<ReadingSettings> {
+  const method = settings.theme !== undefined ? "PUT" : "PATCH";
+  const response = await fetch(`${API_BASE}/reader/settings/`, {
+    method,
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(settings),
+  });
+  if (!response.ok) {
+    throw new Error(
+      `Failed to update reading settings: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingSettings>;
+}
+
+/**
+ * Fetch the table of contents (chapter list) for a book.
+ */
+export async function getChapters(bookId: number): Promise<ChapterSummary[]> {
+  const response = await fetch(`${API_BASE}/books/${bookId}/chapters/`);
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch chapters: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ChapterSummary[]>;
+}
+
+/**
+ * Fetch a specific chapter with full content for reading.
+ */
+export async function getChapterContent(
+  bookId: number,
+  chapterNumber: number
+): Promise<ChapterDetail> {
+  const response = await fetch(
+    `${API_BASE}/books/${bookId}/chapters/${chapterNumber}/`
+  );
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch chapter ${chapterNumber}: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ChapterDetail>;
+}
+
+/**
+ * Fetch reading progress for a book.
+ */
+export async function getReadingProgress(
+  bookId: number
+): Promise<ReadingProgress> {
+  const response = await fetch(`${API_BASE}/books/${bookId}/progress/`);
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch reading progress: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingProgress>;
+}
+
+/**
+ * Update reading progress for a book.
+ */
+export async function updateReadingProgress(
+  bookId: number,
+  progress: Partial<ReadingProgress>
+): Promise<ReadingProgress> {
+  const response = await fetch(`${API_BASE}/books/${bookId}/progress/`, {
+    method: "PUT",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(progress),
+  });
+  if (!response.ok) {
+    throw new Error(
+      `Failed to update reading progress: ${response.status} ${response.statusText}`
+    );
+  }
+  return response.json() as Promise<ReadingProgress>;
+}

web/src/components/BookDetail.tsx

@@ -1,5 +1,5 @@
 /**
- * BookDetail component — full book information display.
+ * BookDetail component — full book information display with reading action.
  */
 
 import type { BookDetail as BookDetailType } from "../types";
@@ -8,9 +8,10 @@ import { READING_STATUS_LABELS } from "../types";
 interface BookDetailProps {
   book: BookDetailType;
   onBack: () => void;
+  onStartReading: (book: BookDetailType) => void;
 }
 
-export default function BookDetail({ book, onBack }: BookDetailProps) {
+export default function BookDetail({ book, onBack, onStartReading }: BookDetailProps) {
   return (
     <div className="book-detail">
       <button
@@ -74,6 +75,23 @@ export default function BookDetail({ book, onBack }: BookDetailProps) {
             </div>
           )}
 
+          <button
+            type="button"
+            className="start-reading-btn"
+            onClick={() => onStartReading(book)}
+          >
+            <svg
+              width="18"
+              height="18"
+              viewBox="0 0 24 24"
+              fill="currentColor"
+              stroke="none"
+            >
+              <polygon points="5 3 19 12 5 21 5 3" />
+            </svg>
+            Start Reading
+          </button>
+
           <div className="book-detail-meta">
             <p>
               <strong>Added:</strong>{" "}

web/src/components/ReaderToolbar.tsx

@@ -0,0 +1,67 @@
+/**
+ * ReaderToolbar — fixed bottom toolbar for the reading view.
+ * Provides TOC toggle, settings toggle, and progress indicator.
+ */
+
+import type { ReadingProgress } from "../types/reader";
+
+interface ReaderToolbarProps {
+  bookTitle: string;
+  chapterTitle: string;
+  progress: ReadingProgress | null;
+  onToggleToc: () => void;
+  onToggleSettings: () => void;
+}
+
+export default function ReaderToolbar({
+  bookTitle,
+  chapterTitle,
+  progress,
+  onToggleToc,
+  onToggleSettings,
+}: ReaderToolbarProps) {
+  const percentage = progress?.percentage ?? 0;
+
+  return (
+    <>
+      {/* Top bar */}
+      <header className="reader-top-bar">
+        <button
+          type="button"
+          className="reader-bar-btn"
+          onClick={onToggleToc}
+          aria-label="Table of contents"
+        >
+          <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+            <line x1="3" y1="6" x2="21" y2="6" />
+            <line x1="3" y1="12" x2="21" y2="12" />
+            <line x1="3" y1="18" x2="21" y2="18" />
+          </svg>
+        </button>
+        <div className="reader-bar-title">
+          <span className="reader-bar-book">{bookTitle}</span>
+          <span className="reader-bar-chapter">{chapterTitle}</span>
+        </div>
+        <button
+          type="button"
+          className="reader-bar-btn"
+          onClick={onToggleSettings}
+          aria-label="Reading settings"
+        >
+          <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+            <circle cx="12" cy="12" r="3" />
+            <path d="M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1 0 2.83 2 2 0 0 1-2.83 0l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-2 2 2 2 0 0 1-2-2v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83 0 2 2 0 0 1 0-2.83l.06-.06A1.65 1.65 0 0 0 4.68 15a1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1-2-2 2 2 0 0 1 2-2h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 0-2.83 2 2 0 0 1 2.83 0l.06.06A1.65 1.65 0 0 0 9 4.68a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 2-2 2 2 0 0 1 2 2v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 0 2 2 0 0 1 0 2.83l-.06.06a1.65 1.65 0 0 0-.33 1.82V9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 2 2 2 2 0 0 1-2 2h-.09a1.65 1.65 0 0 0-1.51 1z" />
+          </svg>
+        </button>
+      </header>
+
+      {/* Bottom progress bar */}
+      <div className="reader-progress-bar">
+        <div
+          className="reader-progress-fill"
+          style={{ width: `${Math.min(percentage, 100)}%` }}
+        />
+      </div>
+    </>
+  );
+}

web/src/components/ReadingSettingsPanel.tsx

@@ -0,0 +1,232 @@
+/**
+ * ReadingSettingsPanel — slide-in drawer from the right for customizing
+ * the reading experience: theme, font, sizing, orientation.
+ */
+
+import { useState } from "react";
+import type {
+  FontFamily,
+  OrientationLock,
+  ReadingSettings,
+  ThemePreset,
+} from "../types/reader";
+
+interface ReadingSettingsPanelProps {
+  settings: ReadingSettings;
+  isOpen: boolean;
+  onClose: () => void;
+  onUpdate: (partial: Partial<ReadingSettings>) => Promise<void>;
+}
+
+const THEME_OPTIONS: { value: ThemePreset; label: string }[] = [
+  { value: "sepia", label: "Sepia" },
+  { value: "dark", label: "Dark" },
+  { value: "light", label: "Light" },
+  { value: "paper", label: "Paper" },
+];
+
+const FONT_OPTIONS: { value: FontFamily; label: string }[] = [
+  { value: "sans-serif", label: "Sans-serif" },
+  { value: "serif", label: "Serif" },
+  { value: "monospace", label: "Monospace" },
+];
+
+const ORIENTATION_OPTIONS: { value: OrientationLock; label: string }[] = [
+  { value: "auto", label: "Auto" },
+  { value: "portrait", label: "Portrait" },
+  { value: "landscape", label: "Landscape" },
+];
+
+export default function ReadingSettingsPanel({
+  settings,
+  isOpen,
+  onClose,
+  onUpdate,
+}: ReadingSettingsPanelProps) {
+  const [saving, setSaving] = useState<Record<string, boolean>>({});
+
+  const handleChange = async (
+    key: keyof ReadingSettings,
+    value: string | number
+  ) => {
+    setSaving((prev) => ({ ...prev, [key]: true }));
+    try {
+      await onUpdate({ [key]: value as never });
+    } finally {
+      setSaving((prev) => ({ ...prev, [key]: false }));
+    }
+  };
+
+  return (
+    <>
+      {/* Overlay */}
+      {isOpen && (
+        <div
+          className="settings-overlay"
+          onClick={onClose}
+          onKeyDown={(e: React.KeyboardEvent) => {
+            if (e.key === "Escape") onClose();
+          }}
+          role="presentation"
+        />
+      )}
+
+      {/* Drawer */}
+      <aside
+        className={`settings-drawer ${isOpen ? "settings-drawer--open" : ""}`}
+      >
+        <div className="settings-header">
+          <h2 className="settings-title">Reading Settings</h2>
+          <button
+            type="button"
+            className="settings-close-btn"
+            onClick={onClose}
+            aria-label="Close settings"
+          >
+            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <line x1="18" y1="6" x2="6" y2="18" />
+              <line x1="6" y1="6" x2="18" y2="18" />
+            </svg>
+          </button>
+        </div>
+
+        <div className="settings-body">
+          {/* Theme Presets */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">Theme</h3>
+            <div className="theme-grid">
+              {THEME_OPTIONS.map((opt) => (
+                <button
+                  key={opt.value}
+                  type="button"
+                  className={`theme-btn ${
+                    settings.theme === opt.value ? "theme-btn--active" : ""
+                  }`}
+                  onClick={() => handleChange("theme", opt.value)}
+                  disabled={saving.theme}
+                >
+                  {opt.label}
+                </button>
+              ))}
+            </div>
+          </section>
+
+          {/* Font Family */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">Font</h3>
+            <div className="font-grid">
+              {FONT_OPTIONS.map((opt) => (
+                <button
+                  key={opt.value}
+                  type="button"
+                  className={`font-btn ${
+                    settings.font_family === opt.value ? "font-btn--active" : ""
+                  }`}
+                  onClick={() => handleChange("font_family", opt.value)}
+                  disabled={saving.font_family}
+                >
+                  {opt.label}
+                </button>
+              ))}
+            </div>
+          </section>
+
+          {/* Font Size Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Font Size: {settings.font_size}px
+            </h3>
+            <input
+              type="range"
+              min="12"
+              max="32"
+              value={settings.font_size}
+              onChange={(e) =>
+                handleChange("font_size", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Font size"
+            />
+          </section>
+
+          {/* Line Height Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Line Height: {settings.line_height.toFixed(1)}
+            </h3>
+            <input
+              type="range"
+              min="1.2"
+              max="2.0"
+              step="0.1"
+              value={settings.line_height}
+              onChange={(e) =>
+                handleChange("line_height", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Line height"
+            />
+          </section>
+
+          {/* Margin Width Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Margins: {settings.margin_width}px
+            </h3>
+            <input
+              type="range"
+              min="8"
+              max="48"
+              value={settings.margin_width}
+              onChange={(e) =>
+                handleChange("margin_width", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Margin width"
+            />
+          </section>
+
+          {/* Brightness Slider */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">
+              Brightness: {settings.brightness}%
+            </h3>
+            <input
+              type="range"
+              min="0"
+              max="100"
+              value={settings.brightness}
+              onChange={(e) =>
+                handleChange("brightness", Number(e.target.value))
+              }
+              className="settings-slider"
+              aria-label="Brightness"
+            />
+          </section>
+
+          {/* Orientation Lock */}
+          <section className="settings-section">
+            <h3 className="settings-section-title">Orientation</h3>
+            <div className="orientation-grid">
+              {ORIENTATION_OPTIONS.map((opt) => (
+                <button
+                  key={opt.value}
+                  type="button"
+                  className={`orientation-btn ${
+                    settings.orientation_lock === opt.value
+                      ? "orientation-btn--active"
+                      : ""
+                  }`}
+                  onClick={() => handleChange("orientation_lock", opt.value)}
+                  disabled={saving.orientation_lock}
+                >
+                  {opt.label}
+                </button>
+              ))}
+            </div>
+          </section>
+        </div>
+      </aside>
+    </>
+  );
+}

web/src/components/TableOfContents.tsx

@@ -0,0 +1,80 @@
+/**
+ * TableOfContents — slide-in drawer listing all chapters.
+ * Tap a chapter to navigate. Current chapter is highlighted.
+ */
+
+import type { ChapterSummary } from "../types/reader";
+
+interface TableOfContentsProps {
+  chapters: ChapterSummary[];
+  currentChapterNumber: number;
+  isOpen: boolean;
+  onClose: () => void;
+  onNavigate: (number: number) => void;
+}
+
+export default function TableOfContents({
+  chapters,
+  currentChapterNumber,
+  isOpen,
+  onClose,
+  onNavigate,
+}: TableOfContentsProps) {
+  const handleChapterClick = (number: number) => {
+    onNavigate(number);
+    onClose();
+  };
+
+  return (
+    <>
+      {/* Overlay */}
+      {isOpen && (
+        <div
+          className="toc-overlay"
+          onClick={onClose}
+          onKeyDown={(e: React.KeyboardEvent) => {
+            if (e.key === "Escape") onClose();
+          }}
+          role="presentation"
+        />
+      )}
+
+      {/* Drawer */}
+      <aside className={`toc-drawer ${isOpen ? "toc-drawer--open" : ""}`}>
+        <div className="toc-header">
+          <h2 className="toc-title">Contents</h2>
+          <button
+            type="button"
+            className="toc-close-btn"
+            onClick={onClose}
+            aria-label="Close table of contents"
+          >
+            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <line x1="18" y1="6" x2="6" y2="18" />
+              <line x1="6" y1="6" x2="18" y2="18" />
+            </svg>
+          </button>
+        </div>
+
+        <nav className="toc-list">
+          {chapters.length === 0 && (
+            <p className="toc-empty">No chapters available.</p>
+          )}
+          {chapters.map((chapter) => (
+            <button
+              key={chapter.number}
+              type="button"
+              className={`toc-item ${
+                chapter.number === currentChapterNumber ? "toc-item--active" : ""
+              }`}
+              onClick={() => handleChapterClick(chapter.number)}
+            >
+              <span className="toc-item-number">{chapter.number}</span>
+              <span className="toc-item-title">{chapter.title}</span>
+            </button>
+          ))}
+        </nav>
+      </aside>
+    </>
+  );
+}

web/src/hooks/useChapters.ts

@@ -0,0 +1,129 @@
+/**
+ * useChapters — fetch chapter list and manage current chapter navigation.
+ */
+
+import { useCallback, useEffect, useState } from "react";
+import { getChapterContent, getChapters } from "../api/reader";
+import type { ChapterDetail, ChapterSummary } from "../types/reader";
+
+export interface UseChaptersReturn {
+  chapters: ChapterSummary[];
+  currentChapter: ChapterDetail | null;
+  currentChapterNumber: number;
+  isLoading: boolean;
+  error: string | null;
+  navigateToChapter: (number: number) => Promise<void>;
+  goToNextChapter: () => Promise<void>;
+  goToPreviousChapter: () => Promise<void>;
+  hasNext: boolean;
+  hasPrevious: boolean;
+}
+
+export function useChapters(
+  bookId: number,
+  initialChapter: number = 1
+): UseChaptersReturn {
+  const [chapters, setChapters] = useState<ChapterSummary[]>([]);
+  const [currentChapter, setCurrentChapter] = useState<ChapterDetail | null>(
+    null
+  );
+  const [currentChapterNumber, setCurrentChapterNumber] =
+    useState<number>(initialChapter);
+  const [isLoading, setIsLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  // Fetch chapter list on mount
+  useEffect(() => {
+    let cancelled = false;
+    setIsLoading(true);
+    getChapters(bookId)
+      .then((data) => {
+        if (!cancelled) {
+          setChapters(data);
+          // If chapters exist and initial chapter is valid, fetch it
+          if (
+            data.length > 0 &&
+            data.some((c) => c.number === currentChapterNumber)
+          ) {
+            return getChapterContent(bookId, currentChapterNumber);
+          }
+          return null;
+        }
+        return null;
+      })
+      .then((chapter) => {
+        if (!cancelled && chapter) {
+          setCurrentChapter(chapter);
+        }
+      })
+      .catch((err: unknown) => {
+        if (!cancelled) {
+          setError(
+            err instanceof Error ? err.message : "Failed to load chapters"
+          );
+        }
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [bookId, currentChapterNumber]);
+
+  const fetchChapter = useCallback(
+    async (number: number) => {
+      setIsLoading(true);
+      setError(null);
+      try {
+        const chapter = await getChapterContent(bookId, number);
+        setCurrentChapter(chapter);
+        setCurrentChapterNumber(number);
+      } catch (err: unknown) {
+        setError(
+          err instanceof Error ? err.message : "Failed to load chapter"
+        );
+      } finally {
+        setIsLoading(false);
+      }
+    },
+    [bookId]
+  );
+
+  const navigateToChapter = useCallback(
+    (number: number) => {
+      fetchChapter(number);
+    },
+    [fetchChapter]
+  );
+
+  const goToNextChapter = useCallback(() => {
+    const next = currentChapterNumber + 1;
+    if (chapters.some((c) => c.number === next)) {
+      fetchChapter(next);
+    }
+  }, [currentChapterNumber, chapters, fetchChapter]);
+
+  const goToPreviousChapter = useCallback(() => {
+    const prev = currentChapterNumber - 1;
+    if (prev >= 1 && chapters.some((c) => c.number === prev)) {
+      fetchChapter(prev);
+    }
+  }, [currentChapterNumber, chapters, fetchChapter]);
+
+  const hasNext = chapters.some((c) => c.number === currentChapterNumber + 1);
+  const hasPrevious = chapters.some((c) => c.number === currentChapterNumber - 1);
+
+  return {
+    chapters,
+    currentChapter,
+    currentChapterNumber,
+    isLoading,
+    error,
+    navigateToChapter,
+    goToNextChapter,
+    goToPreviousChapter,
+    hasNext,
+    hasPrevious,
+  };
+}

web/src/hooks/useReadingProgress.ts

@@ -0,0 +1,99 @@
+/**
+ * useReadingProgress — fetch and update reading progress for a book.
+ * Auto-saves when chapter or position changes.
+ */
+
+import { useCallback, useEffect, useRef, useState } from "react";
+import { getReadingProgress, updateReadingProgress } from "../api/reader";
+import type { ReadingProgress } from "../types/reader";
+
+export interface UseReadingProgressReturn {
+  progress: ReadingProgress | null;
+  isLoading: boolean;
+  error: string | null;
+  saveProgress: (
+    chapter: number,
+    position: number,
+    percentage: number
+  ) => Promise<void>;
+  /** Schedule a debounced save — fires at most once per 3 seconds */
+  debouncedSave: (
+    chapter: number,
+    position: number,
+    percentage: number
+  ) => void;
+}
+
+export function useReadingProgress(
+  bookId: number
+): UseReadingProgressReturn {
+  const [progress, setProgress] = useState<ReadingProgress | null>(null);
+  const [isLoading, setIsLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+  const debounceTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  // Fetch progress on mount
+  useEffect(() => {
+    let cancelled = false;
+    setIsLoading(true);
+    getReadingProgress(bookId)
+      .then((data) => {
+        if (!cancelled) setProgress(data);
+      })
+      .catch((err: unknown) => {
+        if (!cancelled) {
+          setError(
+            err instanceof Error ? err.message : "Failed to load progress"
+          );
+        }
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, [bookId]);
+
+  const saveProgress = useCallback(
+    async (chapter: number, position: number, percentage: number) => {
+      try {
+        const updated = await updateReadingProgress(bookId, {
+          current_chapter: chapter,
+          current_position: position,
+          percentage,
+        });
+        setProgress(updated);
+        setError(null);
+      } catch (err: unknown) {
+        setError(
+          err instanceof Error ? err.message : "Failed to save progress"
+        );
+      }
+    },
+    [bookId]
+  );
+
+  const debouncedSave = useCallback(
+    (chapter: number, position: number, percentage: number) => {
+      if (debounceTimer.current) {
+        clearTimeout(debounceTimer.current);
+      }
+      debounceTimer.current = setTimeout(() => {
+        saveProgress(chapter, position, percentage);
+      }, 3000);
+    },
+    [saveProgress]
+  );
+
+  // Cleanup timer on unmount
+  useEffect(() => {
+    return () => {
+      if (debounceTimer.current) {
+        clearTimeout(debounceTimer.current);
+      }
+    };
+  }, []);
+
+  return { progress, isLoading, error, saveProgress, debouncedSave };
+}

web/src/hooks/useReadingSettings.ts

@@ -0,0 +1,96 @@
+/**
+ * useReadingSettings — fetch and manage user reading preferences.
+ * Applies settings as CSS custom properties on the document root.
+ */
+
+import { useCallback, useEffect, useState } from "react";
+import {
+  getReadingSettings,
+  updateReadingSettings,
+} from "../api/reader";
+import type { ReadingSettings } from "../types/reader";
+
+const DEFAULT_SETTINGS: ReadingSettings = {
+  font_family: "serif",
+  font_size: 18,
+  line_height: 1.6,
+  margin_width: 16,
+  background_color: "#f5f0eb",
+  text_color: "#1a1a1a",
+  brightness: 100,
+  orientation_lock: "auto",
+  theme: "sepia",
+  created_at: "",
+  updated_at: "",
+};
+
+function applyCssVariables(settings: ReadingSettings): void {
+  const root = document.documentElement;
+  root.style.setProperty("--reader-bg", settings.background_color);
+  root.style.setProperty("--reader-text", settings.text_color);
+  root.style.setProperty("--reader-font-family", settings.font_family);
+  root.style.setProperty("--reader-font-size", `${settings.font_size}px`);
+  root.style.setProperty("--reader-line-height", String(settings.line_height));
+  root.style.setProperty("--reader-margin", `${settings.margin_width}px`);
+  root.style.setProperty("--reader-brightness", `${settings.brightness}%`);
+}
+
+export interface UseReadingSettingsReturn {
+  settings: ReadingSettings;
+  isLoading: boolean;
+  error: string | null;
+  updateSettings: (partial: Partial<ReadingSettings>) => Promise<void>;
+}
+
+export function useReadingSettings(): UseReadingSettingsReturn {
+  const [settings, setSettings] = useState<ReadingSettings>(DEFAULT_SETTINGS);
+  const [isLoading, setIsLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  // Fetch settings on mount
+  useEffect(() => {
+    let cancelled = false;
+    setIsLoading(true);
+    getReadingSettings()
+      .then((data) => {
+        if (!cancelled) {
+          setSettings(data);
+          applyCssVariables(data);
+        }
+      })
+      .catch((err: unknown) => {
+        if (!cancelled) {
+          setError(
+            err instanceof Error ? err.message : "Failed to load reading settings"
+          );
+          // Apply defaults
+          applyCssVariables(DEFAULT_SETTINGS);
+        }
+      })
+      .finally(() => {
+        if (!cancelled) setIsLoading(false);
+      });
+    return () => {
+      cancelled = true;
+    };
+  }, []);
+
+  const updateSettings = useCallback(
+    async (partial: Partial<ReadingSettings>) => {
+      try {
+        const updated = await updateReadingSettings(partial);
+        setSettings(updated);
+        applyCssVariables(updated);
+        setError(null);
+      } catch (err: unknown) {
+        setError(
+          err instanceof Error ? err.message : "Failed to update reading settings"
+        );
+        throw err;
+      }
+    },
+    []
+  );
+
+  return { settings, isLoading, error, updateSettings };
+}

web/src/pages/BookDetailPage.tsx

@@ -10,9 +10,10 @@ import BookDetailComponent from "../components/BookDetail";
 interface BookDetailPageProps {
   bookId: number;
   onBack: () => void;
+  onStartReading: (book: BookDetailType) => void;
 }
 
-export default function BookDetailPage({ bookId, onBack }: BookDetailPageProps) {
+export default function BookDetailPage({ bookId, onBack, onStartReading }: BookDetailPageProps) {
   const [book, setBook] = useState<BookDetailType | null>(null);
   const [isLoading, setIsLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
@@ -59,5 +60,5 @@ export default function BookDetailPage({ bookId, onBack }: BookDetailPageProps)
     );
   }
 
-  return <BookDetailComponent book={book} onBack={onBack} />;
+  return <BookDetailComponent book={book} onBack={onBack} onStartReading={onStartReading} />;
 }

web/src/pages/ReadingPage.tsx

@@ -0,0 +1,199 @@
+/**
+ * ReadingPage — full-screen reading view for ebooks.
+ * Integrates TOC drawer, settings panel, chapter navigation, and progress tracking.
+ */
+
+import { lazy, Suspense, useCallback, useEffect, useState } from "react";
+import { useChapters } from "../hooks/useChapters";
+import { useReadingProgress } from "../hooks/useReadingProgress";
+import { useReadingSettings } from "../hooks/useReadingSettings";
+import type { BookDetail as BookDetailType } from "../types";
+
+const ReaderToolbar = lazy(() => import("../components/ReaderToolbar"));
+const TableOfContents = lazy(() => import("../components/TableOfContents"));
+const ReadingSettingsPanel = lazy(
+  () => import("../components/ReadingSettingsPanel")
+);
+
+interface ReadingPageProps {
+  book: BookDetailType;
+  onBack: () => void;
+}
+
+export default function ReadingPage({ book, onBack }: ReadingPageProps) {
+  const [tocOpen, setTocOpen] = useState(false);
+  const [settingsOpen, setSettingsOpen] = useState(false);
+
+  const { settings, updateSettings } = useReadingSettings();
+  const {
+    chapters,
+    currentChapter,
+    currentChapterNumber,
+    isLoading,
+    error,
+    navigateToChapter,
+    goToNextChapter,
+    goToPreviousChapter,
+    hasNext,
+    hasPrevious,
+  } = useChapters(book.id, 1);
+
+  const { progress, debouncedSave } = useReadingProgress(book.id);
+
+  // Auto-save progress when chapter changes
+  useEffect(() => {
+    if (currentChapter && currentChapterNumber > 0) {
+      debouncedSave(currentChapterNumber, 0, (currentChapterNumber / Math.max(chapters.length, 1)) * 100);
+    }
+  }, [currentChapterNumber, currentChapter?.id]);
+
+  const handleKeyDown = useCallback(
+    (e: KeyboardEvent) => {
+      if (e.key === "ArrowLeft" && hasPrevious) {
+        goToPreviousChapter();
+      } else if (e.key === "ArrowRight" && hasNext) {
+        goToNextChapter();
+      } else if (e.key === "Escape") {
+        setTocOpen(false);
+        setSettingsOpen(false);
+      }
+    },
+    [hasNext, hasPrevious, goToNextChapter, goToPreviousChapter]
+  );
+
+  useEffect(() => {
+    document.addEventListener("keydown", handleKeyDown);
+    return () => document.removeEventListener("keydown", handleKeyDown);
+  }, [handleKeyDown]);
+
+  // Lock/unlock orientation via CSS
+  useEffect(() => {
+    const root = document.documentElement;
+    if (settings.orientation_lock !== "auto") {
+      root.style.setProperty(
+        "--reader-orientation",
+        settings.orientation_lock === "portrait" ? "portrait" : "landscape"
+      );
+    } else {
+      root.style.removeProperty("--reader-orientation");
+    }
+  }, [settings.orientation_lock]);
+
+  // Show loading state
+  if (isLoading && !currentChapter) {
+    return (
+      <div className="reader-loading">
+        <div className="spinner" />
+        <p>Loading reader...</p>
+      </div>
+    );
+  }
+
+  if (error) {
+    return (
+      <div className="reader-loading">
+        <p className="reader-error">{error}</p>
+        <button type="button" className="back-button" onClick={onBack}>
+          Back to book
+        </button>
+      </div>
+    );
+  }
+
+  return (
+    <Suspense
+      fallback={
+        <div className="reader-loading">
+          <div className="spinner" />
+        </div>
+      }
+    >
+      <div className="reader-container">
+        <ReaderToolbar
+          bookTitle={book.title}
+          chapterTitle={currentChapter?.title ?? "Loading..."}
+          progress={progress}
+          onToggleToc={() => setTocOpen((v) => !v)}
+          onToggleSettings={() => setSettingsOpen((v) => !v)}
+        />
+
+        <TableOfContents
+          chapters={chapters}
+          currentChapterNumber={currentChapterNumber}
+          isOpen={tocOpen}
+          onClose={() => setTocOpen(false)}
+          onNavigate={navigateToChapter}
+        />
+
+        <ReadingSettingsPanel
+          settings={settings}
+          isOpen={settingsOpen}
+          onClose={() => setSettingsOpen(false)}
+          onUpdate={updateSettings}
+        />
+
+        {/* Main reading area */}
+        <main className="reader-content">
+          {isLoading ? (
+            <div className="reader-loading">
+              <div className="spinner" />
+              <p>Loading chapter...</p>
+            </div>
+          ) : currentChapter ? (
+            <article className="reader-chapter">
+              <h1 className="reader-chapter-title">{currentChapter.title}</h1>
+              <div
+                className="reader-chapter-body"
+                dangerouslySetInnerHTML={{
+                  __html: currentChapter.content,
+                }}
+              />
+            </article>
+          ) : (
+            <div className="reader-loading">
+              <p>Select a chapter from the table of contents to start reading.</p>
+            </div>
+          )}
+        </main>
+
+        {/* Bottom navigation bar */}
+        <nav className="reader-nav">
+          <button
+            type="button"
+            className={`reader-nav-btn ${!hasPrevious ? "reader-nav-btn--disabled" : ""}`}
+            onClick={goToPreviousChapter}
+            disabled={!hasPrevious}
+          >
+            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <polyline points="15 18 9 12 15 6" />
+            </svg>
+            Previous
+          </button>
+
+          <button
+            type="button"
+            className="reader-nav-btn reader-nav-btn--back"
+            onClick={onBack}
+          >
+            <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <path d="M20 12H4M10 18l-6-6 6-6" />
+            </svg>
+            Library
+          </button>
+
+          <button
+            type="button"
+            className={`reader-nav-btn ${!hasNext ? "reader-nav-btn--disabled" : ""}`}
+            onClick={goToNextChapter}
+            disabled={!hasNext}
+          >
+            Next
+            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <polyline points="9 18 15 12 9 6" />
+            </svg>
+          </button>
+        </nav>
+      </div>
+    </Suspense>
+  );
+}

web/src/reader.css

@@ -0,0 +1,621 @@
+/* ============================================================
+   Cloud Reader — Reading View Styles
+   Mobile-first reading experience with theme support
+   ============================================================ */
+
+/* --- CSS Custom Properties (overridden by JS) --- */
+:root {
+  --reader-bg: #f5f0eb;
+  --reader-text: #1a1a1a;
+  --reader-font-family: Georgia, "Times New Roman", serif;
+  --reader-font-size: 18px;
+  --reader-line-height: 1.6;
+  --reader-margin: 16px;
+  --reader-brightness: 100%;
+  --reader-toolbar-bg: rgba(26, 26, 26, 0.95);
+  --reader-toolbar-text: #e0e0e0;
+  --reader-accent: #6c8cff;
+}
+
+/* --- Reading Container --- */
+.reader-container {
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background: var(--reader-bg);
+  color: var(--reader-text);
+  font-family: var(--reader-font-family);
+  font-size: var(--reader-font-size);
+  line-height: var(--reader-line-height);
+  filter: brightness(var(--reader-brightness));
+  display: flex;
+  flex-direction: column;
+  z-index: 100;
+  overflow: hidden;
+}
+
+/* Orientation lock */
+@supports (--reader-orientation: portrait) {
+  .reader-container {
+    orientation: var(--reader-orientation);
+  }
+}
+
+@media (orientation: landascape) {
+  .reader-container {
+    --reader-margin: 24px;
+  }
+}
+
+/* --- Top Toolbar --- */
+.reader-top-bar {
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  height: 52px;
+  background: var(--reader-toolbar-bg);
+  color: var(--reader-toolbar-text);
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0 12px;
+  z-index: 120;
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+}
+
+.reader-bar-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 40px;
+  height: 40px;
+  background: transparent;
+  border: none;
+  color: var(--reader-toolbar-text);
+  cursor: pointer;
+  border-radius: 8px;
+  transition: background 0.15s;
+}
+
+.reader-bar-btn:hover {
+  background: rgba(255, 255, 255, 0.1);
+}
+
+.reader-bar-title {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 1px;
+  min-width: 0;
+  flex: 1;
+  padding: 0 8px;
+}
+
+.reader-bar-book {
+  font-size: 0.8rem;
+  font-weight: 600;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  max-width: 200px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+.reader-bar-chapter {
+  font-size: 0.7rem;
+  opacity: 0.7;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  max-width: 200px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+/* --- Progress Bar --- */
+.reader-progress-bar {
+  position: fixed;
+  top: 52px;
+  left: 0;
+  right: 0;
+  height: 3px;
+  background: rgba(255, 255, 255, 0.1);
+  z-index: 120;
+}
+
+.reader-progress-fill {
+  height: 100%;
+  background: var(--reader-accent);
+  transition: width 0.3s ease;
+}
+
+/* --- Main Content Area --- */
+.reader-content {
+  flex: 1;
+  overflow-y: auto;
+  padding: 72px var(--reader-margin) 72px;
+  -webkit-overflow-scrolling: touch;
+  scroll-behavior: smooth;
+}
+
+/* --- Chapter Article --- */
+.reader-chapter {
+  max-width: 680px;
+  margin: 0 auto;
+}
+
+.reader-chapter-title {
+  font-size: 1.6em;
+  font-weight: 700;
+  line-height: 1.3;
+  margin-bottom: 0.75em;
+  padding-bottom: 0.5em;
+  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
+  color: var(--reader-text);
+}
+
+/* Chapter body — content from API (could be HTML/markdown-rendered) */
+.reader-chapter-body {
+  font-size: 1em;
+  line-height: var(--reader-line-height);
+}
+
+.reader-chapter-body p {
+  margin-bottom: 1.2em;
+  text-align: justify;
+  hyphens: auto;
+}
+
+.reader-chapter-body h2,
+.reader-chapter-body h3,
+.reader-chapter-body h4 {
+  margin-top: 1.5em;
+  margin-bottom: 0.6em;
+  line-height: 1.3;
+}
+
+.reader-chapter-body blockquote {
+  border-left: 3px solid var(--reader-accent);
+  padding-left: 1em;
+  margin: 1em 0;
+  opacity: 0.85;
+  font-style: italic;
+}
+
+.reader-chapter-body img {
+  max-width: 100%;
+  height: auto;
+  border-radius: 4px;
+  margin: 1em 0;
+}
+
+.reader-chapter-body ul,
+.reader-chapter-body ol {
+  padding-left: 1.5em;
+  margin-bottom: 1.2em;
+}
+
+.reader-chapter-body li {
+  margin-bottom: 0.4em;
+}
+
+/* --- Navigation Bar (Bottom) --- */
+.reader-nav {
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  right: 0;
+  height: 56px;
+  background: var(--reader-toolbar-bg);
+  color: var(--reader-toolbar-text);
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0 12px;
+  z-index: 120;
+  gap: 8px;
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+}
+
+.reader-nav-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 6px;
+  padding: 8px 14px;
+  background: transparent;
+  border: 1px solid rgba(255, 255, 255, 0.2);
+  border-radius: 8px;
+  color: var(--reader-toolbar-text);
+  font-size: 0.85rem;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+  cursor: pointer;
+  transition: all 0.15s;
+}
+
+.reader-nav-btn:hover:not(.reader-nav-btn--disabled) {
+  border-color: var(--reader-accent);
+  color: var(--reader-accent);
+}
+
+.reader-nav-btn--disabled {
+  opacity: 0.3;
+  cursor: not-allowed;
+}
+
+.reader-nav-btn--back {
+  background: rgba(108, 140, 255, 0.15);
+  border-color: rgba(108, 140, 255, 0.3);
+}
+
+.reader-nav-btn--back:hover {
+  background: rgba(108, 140, 255, 0.25);
+  color: var(--reader-accent);
+}
+
+/* --- TOC Drawer --- */
+.toc-overlay,
+.settings-overlay {
+  position: fixed;
+  top: 0;
+  left: 0;
+  right: 0;
+  bottom: 0;
+  background: rgba(0, 0, 0, 0.5);
+  z-index: 130;
+  animation: fadeIn 0.2s ease;
+}
+
+@keyframes fadeIn {
+  from { opacity: 0; }
+  to { opacity: 1; }
+}
+
+.toc-drawer,
+.settings-drawer {
+  position: fixed;
+  top: 0;
+  bottom: 0;
+  width: 300px;
+  max-width: 85vw;
+  background: var(--reader-toolbar-bg);
+  color: var(--reader-toolbar-text);
+  z-index: 140;
+  display: flex;
+  flex-direction: column;
+  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
+}
+
+.toc-drawer {
+  left: 0;
+  transform: translateX(-100%);
+}
+
+.toc-drawer--open {
+  transform: translateX(0);
+}
+
+.settings-drawer {
+  right: 0;
+  transform: translateX(100%);
+}
+
+.settings-drawer--open {
+  transform: translateX(0);
+}
+
+.toc-header,
+.settings-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 16px;
+  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
+}
+
+.toc-title,
+.settings-title {
+  font-size: 1.1rem;
+  font-weight: 700;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+.toc-close-btn,
+.settings-close-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 32px;
+  height: 32px;
+  background: transparent;
+  border: none;
+  color: var(--reader-toolbar-text);
+  cursor: pointer;
+  border-radius: 6px;
+  transition: background 0.15s;
+}
+
+.toc-close-btn:hover,
+.settings-close-btn:hover {
+  background: rgba(255, 255, 255, 0.1);
+}
+
+/* --- TOC List --- */
+.toc-list {
+  flex: 1;
+  overflow-y: auto;
+  padding: 8px 0;
+}
+
+.toc-empty {
+  padding: 24px 16px;
+  text-align: center;
+  opacity: 0.6;
+  font-size: 0.9rem;
+}
+
+.toc-item {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  width: 100%;
+  padding: 10px 16px;
+  background: transparent;
+  border: none;
+  color: var(--reader-toolbar-text);
+  font-size: 0.9rem;
+  text-align: left;
+  cursor: pointer;
+  transition: background 0.15s;
+  font-family: inherit;
+}
+
+.toc-item:hover {
+  background: rgba(255, 255, 255, 0.08);
+}
+
+.toc-item--active {
+  background: rgba(108, 140, 255, 0.15);
+  color: var(--reader-accent);
+  font-weight: 600;
+}
+
+.toc-item-number {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  min-width: 24px;
+  height: 24px;
+  font-size: 0.75rem;
+  font-weight: 700;
+  border-radius: 4px;
+  background: rgba(255, 255, 255, 0.1);
+  padding: 0 4px;
+}
+
+.toc-item-title {
+  flex: 1;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+/* --- Settings Panel --- */
+.settings-body {
+  flex: 1;
+  overflow-y: auto;
+  padding: 12px 16px 32px;
+}
+
+.settings-section {
+  margin-bottom: 20px;
+}
+
+.settings-section-title {
+  font-size: 0.75rem;
+  font-weight: 700;
+  text-transform: uppercase;
+  letter-spacing: 0.06em;
+  color: rgba(255, 255, 255, 0.5);
+  margin-bottom: 8px;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+}
+
+/* Theme grid */
+.theme-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 8px;
+}
+
+.theme-btn {
+  padding: 10px;
+  border: 1px solid rgba(255, 255, 255, 0.15);
+  border-radius: 8px;
+  background: transparent;
+  color: var(--reader-toolbar-text);
+  font-size: 0.85rem;
+  cursor: pointer;
+  transition: all 0.15s;
+  font-family: inherit;
+}
+
+.theme-btn:hover {
+  border-color: rgba(255, 255, 255, 0.3);
+}
+
+.theme-btn--active {
+  border-color: var(--reader-accent);
+  background: rgba(108, 140, 255, 0.15);
+  color: var(--reader-accent);
+  font-weight: 600;
+}
+
+/* Font grid */
+.font-grid,
+.orientation-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr 1fr;
+  gap: 8px;
+}
+
+.font-btn,
+.orientation-btn {
+  padding: 10px 8px;
+  border: 1px solid rgba(255, 255, 255, 0.15);
+  border-radius: 8px;
+  background: transparent;
+  color: var(--reader-toolbar-text);
+  font-size: 0.85rem;
+  cursor: pointer;
+  transition: all 0.15s;
+  font-family: inherit;
+}
+
+.font-btn:hover,
+.orientation-btn:hover {
+  border-color: rgba(255, 255, 255, 0.3);
+}
+
+.font-btn--active,
+.orientation-btn--active {
+  border-color: var(--reader-accent);
+  background: rgba(108, 140, 255, 0.15);
+  color: var(--reader-accent);
+  font-weight: 600;
+}
+
+/* Sliders */
+.settings-slider {
+  width: 100%;
+  height: 6px;
+  -webkit-appearance: none;
+  appearance: none;
+  background: rgba(255, 255, 255, 0.2);
+  border-radius: 3px;
+  outline: none;
+  cursor: pointer;
+}
+
+.settings-slider::-webkit-slider-thumb {
+  -webkit-appearance: none;
+  width: 20px;
+  height: 20px;
+  border-radius: 50%;
+  background: var(--reader-accent);
+  border: 2px solid white;
+  cursor: pointer;
+  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
+}
+
+.settings-slider::-moz-range-thumb {
+  width: 20px;
+  height: 20px;
+  border-radius: 50%;
+  background: var(--reader-accent);
+  border: 2px solid white;
+  cursor: pointer;
+}
+
+/* --- Start Reading Button (in book detail) --- */
+.start-reading-btn {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  padding: 12px 24px;
+  background: var(--reader-accent);
+  border: none;
+  border-radius: 8px;
+  color: white;
+  font-size: 1rem;
+  font-weight: 600;
+  cursor: pointer;
+  transition: all 0.2s;
+  margin-top: 16px;
+  margin-bottom: 16px;
+  font-family: inherit;
+}
+
+.start-reading-btn:hover {
+  background: #5a7ae8;
+  transform: translateY(-1px);
+  box-shadow: 0 4px 12px rgba(108, 140, 255, 0.3);
+}
+
+/* --- Loading State --- */
+.reader-loading {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 12px;
+  padding: 48px;
+  color: var(--reader-text);
+}
+
+.reader-error {
+  color: #ef4444;
+  text-align: center;
+}
+
+/* --- Responsive --- */
+@media (max-width: 480px) {
+  .reader-chapter {
+    max-width: 100%;
+  }
+
+  .reader-nav-btn {
+    padding: 8px 10px;
+    font-size: 0.8rem;
+  }
+
+  .reader-nav-btn span {
+    display: none;
+  }
+
+  .toc-drawer,
+  .settings-drawer {
+    max-width: 100vw;
+  }
+
+  .reader-chapter-title {
+    font-size: 1.3em;
+  }
+}
+
+@media (min-width: 768px) {
+  .reader-chapter {
+    max-width: 720px;
+  }
+
+  .reader-chapter-body {
+    font-size: 1.05em;
+  }
+}
+
+/* --- Landscape on Mobile --- */
+@media (orientation: landscape) and (max-height: 500px) {
+  .reader-top-bar {
+    height: 44px;
+  }
+
+  .reader-content {
+    padding-top: 60px;
+    padding-bottom: 60px;
+  }
+
+  .reader-chapter-title {
+    font-size: 1.2em;
+  }
+}
+
+/* --- Dark mode theme override when reader uses light theme but system is dark --- */
+@media (prefers-color-scheme: dark) {
+  .reader-container[data-theme="light"] {
+    --reader-toolbar-bg: rgba(255, 255, 255, 0.95);
+    --reader-toolbar-text: #1a1a1a;
+  }
+}

web/src/types/reader.ts

@@ -0,0 +1,44 @@
+/**
+ * TypeScript interfaces for the Cloud Reader reader module.
+ * Reading view, settings, chapters, and progress types.
+ */
+
+export interface ChapterSummary {
+  id: number;
+  book: number;
+  title: string;
+  number: number;
+}
+
+export interface ChapterDetail extends ChapterSummary {
+  content: string;
+  created_at: string;
+  updated_at: string;
+}
+
+export interface ReadingSettings {
+  font_family: "sans-serif" | "serif" | "monospace";
+  font_size: number;
+  line_height: number;
+  margin_width: number;
+  background_color: string;
+  text_color: string;
+  brightness: number;
+  orientation_lock: "auto" | "portrait" | "landscape";
+  theme: "sepia" | "dark" | "light" | "paper";
+  created_at: string;
+  updated_at: string;
+}
+
+export type ThemePreset = ReadingSettings["theme"];
+export type FontFamily = ReadingSettings["font_family"];
+export type OrientationLock = ReadingSettings["orientation_lock"];
+
+export interface ReadingProgress {
+  id: number;
+  book: number;
+  current_chapter: number;
+  current_position: number;
+  percentage: number;
+  updated_at: string;
+}