feat: implement reading pace notifications (US #33)

Backend:
- New hermes app with ReadingGroup, GroupMeeting, GroupMembership models
- NotificationPreference (per-user: enable/disable, frequency daily/weekly)
- PaceNotification model for tracking sent/dismissed notifications
- Pace calculation service comparing current progress vs meeting targets
- API endpoints: pace status, notification preferences CRUD, reminders, dismiss
- Ahead/behind/on_track/completed status determination

Frontend:
- PaceNotification component for in-app alerts (behind/ahead/on_track statuses)
- ReadingPaceBanner — persistent banner in reader view
- Notification settings in Settings page (enable/disable, frequency, reminders)
- API client module (groupsApi) for all notification endpoints

backend/apps/groups/admin.py

@@ -0,0 +1,38 @@
+from django.contrib import admin
+
+from apps.groups.models import (
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    ReadingGroup,
+)
+
+
+@admin.register(ReadingGroup)
+class ReadingGroupAdmin(admin.ModelAdmin):
+    list_display = ["name", "created_by", "created_at"]
+    search_fields = ["name"]
+
+
+@admin.register(GroupMembership)
+class GroupMembershipAdmin(admin.ModelAdmin):
+    list_display = ["user", "group", "role", "joined_at"]
+    list_filter = ["role"]
+
+
+@admin.register(GroupMeeting)
+class GroupMeetingAdmin(admin.ModelAdmin):
+    list_display = ["group", "title", "target_section_label", "scheduled_at"]
+    list_filter = ["group"]
+
+
+@admin.register(NotificationPreference)
+class NotificationPreferenceAdmin(admin.ModelAdmin):
+    list_display = ["user", "pace_notifications_enabled", "reminder_enabled", "frequency"]
+
+
+@admin.register(PaceNotification)
+class PaceNotificationAdmin(admin.ModelAdmin):
+    list_display = ["user", "meeting", "status", "created_at"]
+    list_filter = ["status"]

backend/apps/groups/apps.py

@@ -0,0 +1,8 @@
+from django.apps import AppConfig
+
+
+class GroupsConfig(AppConfig):
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "apps.groups"
+    verbose_name = "Reading Groups"
+    label = "groups"

backend/apps/groups/migrations/0001_initial.py

@@ -0,0 +1,109 @@
+# Generated by Django 5.1.7 on 2026-06-20 19:22
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        ('books', '0003_readingprogress_epub_location'),
+        ('users', '0001_initial'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='NotificationPreference',
+            fields=[
+                ('user', models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, primary_key=True, related_name='notification_preference', serialize=False, to=settings.AUTH_USER_MODEL)),
+                ('pace_notifications_enabled', models.BooleanField(default=True)),
+                ('reminder_enabled', models.BooleanField(default=True)),
+                ('frequency', models.CharField(choices=[('daily', 'Daily'), ('weekly', 'Weekly')], default='daily', max_length=16)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('updated_at', models.DateTimeField(auto_now=True)),
+            ],
+            options={
+                'verbose_name': 'Notification Preference',
+                'verbose_name_plural': 'Notification Preferences',
+                'db_table': 'groups_notification_preference',
+            },
+        ),
+        migrations.CreateModel(
+            name='ReadingGroup',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(db_index=True, max_length=256)),
+                ('description', models.TextField(blank=True, default='')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('book', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='reading_groups', to='books.book')),
+                ('created_by', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='created_groups', to=settings.AUTH_USER_MODEL)),
+                ('ebook', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='reading_groups', to='books.ebook')),
+            ],
+            options={
+                'verbose_name': 'Reading Group',
+                'verbose_name_plural': 'Reading Groups',
+                'db_table': 'groups_reading_group',
+                'ordering': ['-created_at'],
+            },
+        ),
+        migrations.CreateModel(
+            name='GroupMeeting',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('title', models.CharField(blank=True, default='', max_length=512)),
+                ('scheduled_at', models.DateTimeField(db_index=True)),
+                ('target_section', models.PositiveIntegerField(default=0, help_text='Target chapter/section index to reach by this meeting')),
+                ('target_section_label', models.CharField(blank=True, default='', help_text="Human-readable label for the target section (e.g. 'Section 3')", max_length=512)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('group', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='meetings', to='groups.readinggroup')),
+            ],
+            options={
+                'verbose_name': 'Group Meeting',
+                'verbose_name_plural': 'Group Meetings',
+                'db_table': 'groups_meeting',
+                'ordering': ['scheduled_at'],
+            },
+        ),
+        migrations.CreateModel(
+            name='PaceNotification',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('status', models.CharField(choices=[('pending', 'Pending'), ('sent', 'Sent'), ('dismissed', 'Dismissed')], default='pending', max_length=16)),
+                ('current_section', models.PositiveIntegerField(default=0)),
+                ('target_section', models.PositiveIntegerField(default=0)),
+                ('ahead_behind_delta', models.IntegerField(default=0)),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('ebook', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='pace_notifications', to='books.ebook')),
+                ('meeting', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='pace_notifications', to='groups.groupmeeting')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='pace_notifications', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'verbose_name': 'Pace Notification',
+                'verbose_name_plural': 'Pace Notifications',
+                'db_table': 'groups_pace_notification',
+                'ordering': ['-created_at'],
+                'indexes': [models.Index(fields=['user', 'meeting', 'ebook'], name='groups_pace_user_id_18e929_idx')],
+            },
+        ),
+        migrations.CreateModel(
+            name='GroupMembership',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('role', models.CharField(choices=[('admin', 'Admin'), ('member', 'Member')], default='member', max_length=16)),
+                ('joined_at', models.DateTimeField(auto_now_add=True)),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='group_memberships', to=settings.AUTH_USER_MODEL)),
+                ('group', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='memberships', to='groups.readinggroup')),
+            ],
+            options={
+                'verbose_name': 'Group Membership',
+                'verbose_name_plural': 'Group Memberships',
+                'db_table': 'groups_membership',
+                'indexes': [models.Index(fields=['user', 'group'], name='groups_memb_user_id_9cda7e_idx')],
+                'unique_together': {('user', 'group')},
+            },
+        ),
+    ]

backend/apps/groups/models.py

@@ -0,0 +1,190 @@
+from __future__ import annotations
+
+from django.conf import settings
+from django.db import models
+
+
+class FrequencyChoice(models.TextChoices):
+    DAILY = "daily", "Daily"
+    WEEKLY = "weekly", "Weekly"
+
+
+class MembershipRole(models.TextChoices):
+    ADMIN = "admin", "Admin"
+    MEMBER = "member", "Member"
+
+
+class NotificationStatus(models.TextChoices):
+    PENDING = "pending", "Pending"
+    SENT = "sent", "Sent"
+    DISMISSED = "dismissed", "Dismissed"
+
+
+class ReadingGroup(models.Model):
+    """A group of users reading a book together with scheduled meetings."""
+
+    name = models.CharField(max_length=256, db_index=True)
+    description = models.TextField(blank=True, default="")
+    book = models.ForeignKey(
+        "books.Book",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="reading_groups",
+    )
+    ebook = models.ForeignKey(
+        "books.EBook",
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="reading_groups",
+    )
+    created_by = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="created_groups",
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "groups_reading_group"
+        verbose_name = "Reading Group"
+        verbose_name_plural = "Reading Groups"
+        ordering = ["-created_at"]
+
+    def __str__(self) -> str:
+        return self.name
+
+
+class GroupMembership(models.Model):
+    """User membership in a reading group."""
+
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="group_memberships",
+    )
+    group = models.ForeignKey(
+        ReadingGroup,
+        on_delete=models.CASCADE,
+        related_name="memberships",
+    )
+    role = models.CharField(
+        max_length=16,
+        choices=MembershipRole.choices,
+        default=MembershipRole.MEMBER,
+    )
+    joined_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "groups_membership"
+        verbose_name = "Group Membership"
+        verbose_name_plural = "Group Memberships"
+        unique_together = [("user", "group")]
+        indexes = [models.Index(fields=["user", "group"])]
+
+    def __str__(self) -> str:
+        return f"{self.user} in {self.group}"
+
+
+class GroupMeeting(models.Model):
+    """A scheduled meeting for a reading group with a target section."""
+
+    group = models.ForeignKey(
+        ReadingGroup,
+        on_delete=models.CASCADE,
+        related_name="meetings",
+    )
+    title = models.CharField(max_length=512, blank=True, default="")
+    scheduled_at = models.DateTimeField(db_index=True)
+    target_section = models.PositiveIntegerField(
+        default=0,
+        help_text="Target chapter/section index to reach by this meeting",
+    )
+    target_section_label = models.CharField(
+        max_length=512,
+        blank=True,
+        default="",
+        help_text="Human-readable label for the target section (e.g. 'Section 3')",
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "groups_meeting"
+        verbose_name = "Group Meeting"
+        verbose_name_plural = "Group Meetings"
+        ordering = ["scheduled_at"]
+
+    def __str__(self) -> str:
+        return f"{self.group.name} — {self.title or self.target_section_label} ({self.scheduled_at.date()})"
+
+
+class NotificationPreference(models.Model):
+    """Per-user notification settings for reading pace alerts."""
+
+    user = models.OneToOneField(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="notification_preference",
+        primary_key=True,
+    )
+    pace_notifications_enabled = models.BooleanField(default=True)
+    reminder_enabled = models.BooleanField(default=True)
+    frequency = models.CharField(
+        max_length=16,
+        choices=FrequencyChoice.choices,
+        default=FrequencyChoice.DAILY,
+    )
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        db_table = "groups_notification_preference"
+        verbose_name = "Notification Preference"
+        verbose_name_plural = "Notification Preferences"
+
+    def __str__(self) -> str:
+        return f"{self.user} — pace={'on' if self.pace_notifications_enabled else 'off'}, freq={self.frequency}"
+
+
+class PaceNotification(models.Model):
+    """Tracks reading pace notifications sent to users to avoid duplicates."""
+
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="pace_notifications",
+    )
+    meeting = models.ForeignKey(
+        GroupMeeting,
+        on_delete=models.CASCADE,
+        related_name="pace_notifications",
+    )
+    ebook = models.ForeignKey(
+        "books.EBook",
+        on_delete=models.CASCADE,
+        related_name="pace_notifications",
+        null=True,
+        blank=True,
+    )
+    status = models.CharField(
+        max_length=16,
+        choices=NotificationStatus.choices,
+        default=NotificationStatus.PENDING,
+    )
+    current_section = models.PositiveIntegerField(default=0)
+    target_section = models.PositiveIntegerField(default=0)
+    ahead_behind_delta = models.IntegerField(default=0)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = "groups_pace_notification"
+        verbose_name = "Pace Notification"
+        verbose_name_plural = "Pace Notifications"
+        ordering = ["-created_at"]
+        indexes = [
+            models.Index(fields=["user", "meeting", "ebook"]),
+        ]
+
+    def __str__(self) -> str:
+        return f"{self.user} — meeting {self.meeting_id}: {self.get_status_display()}"

backend/apps/groups/serializers.py

@@ -0,0 +1,137 @@
+from __future__ import annotations
+
+from rest_framework import serializers
+
+from apps.groups.models import (
+    FrequencyChoice,
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    ReadingGroup,
+)
+from apps.groups.services.pace import PaceStatus
+
+
+class NotificationPreferenceSerializer(serializers.ModelSerializer):
+    class Meta:
+        model = NotificationPreference
+        fields = [
+            "pace_notifications_enabled",
+            "reminder_enabled",
+            "frequency",
+        ]
+
+    def validate_frequency(self, value: str) -> str:
+        valid = {choice[0] for choice in FrequencyChoice.choices}
+        if value not in valid:
+            raise serializers.ValidationError(
+                f"Frequency must be one of: {', '.join(valid)}"
+            )
+        return value
+
+
+class GroupMeetingSerializer(serializers.ModelSerializer):
+    group_name = serializers.CharField(source="group.name", read_only=True)
+
+    class Meta:
+        model = GroupMeeting
+        fields = [
+            "id",
+            "group",
+            "group_name",
+            "title",
+            "scheduled_at",
+            "target_section",
+            "target_section_label",
+            "created_at",
+        ]
+        read_only_fields = ["id", "created_at"]
+
+    def validate_target_section(self, value: int) -> int:
+        if value < 0:
+            raise serializers.ValidationError("Target section must be non-negative.")
+        return value
+
+
+class ReadingGroupSerializer(serializers.ModelSerializer):
+    member_count = serializers.SerializerMethodField()
+    meeting_count = serializers.SerializerMethodField()
+
+    class Meta:
+        model = ReadingGroup
+        fields = [
+            "id",
+            "name",
+            "description",
+            "book",
+            "ebook",
+            "created_by",
+            "created_at",
+            "member_count",
+            "meeting_count",
+        ]
+        read_only_fields = ["id", "created_by", "created_at"]
+
+    def get_member_count(self, obj: ReadingGroup) -> int:
+        return obj.memberships.count()
+
+    def get_meeting_count(self, obj: ReadingGroup) -> int:
+        return obj.meetings.count()
+
+
+class GroupMembershipSerializer(serializers.ModelSerializer):
+    user_email = serializers.CharField(source="user.email", read_only=True)
+    group_name = serializers.CharField(source="group.name", read_only=True)
+
+    class Meta:
+        model = GroupMembership
+        fields = ["id", "user", "user_email", "group", "group_name", "role", "joined_at"]
+        read_only_fields = ["id", "joined_at"]
+
+
+class PaceNotificationSerializer(serializers.ModelSerializer):
+    status_display = serializers.CharField(source="get_status_display", read_only=True)
+
+    class Meta:
+        model = PaceNotification
+        fields = [
+            "id",
+            "user",
+            "meeting",
+            "ebook",
+            "status",
+            "status_display",
+            "current_section",
+            "target_section",
+            "ahead_behind_delta",
+            "created_at",
+        ]
+        read_only_fields = ["id", "created_at"]
+
+
+class PaceStatusSerializer(serializers.Serializer):
+    meeting_id = serializers.IntegerField()
+    meeting_title = serializers.CharField()
+    scheduled_at = serializers.CharField()
+    target_section = serializers.IntegerField()
+    target_section_label = serializers.CharField()
+    current_section = serializers.IntegerField()
+    ahead_behind_delta = serializers.IntegerField()
+    status = serializers.CharField()
+    days_until_meeting = serializers.IntegerField()
+    sections_to_catch_up = serializers.IntegerField()
+    ebook_id = serializers.IntegerField()
+    ebook_title = serializers.CharField()
+
+
+class ReminderSerializer(serializers.Serializer):
+    meeting_id = serializers.IntegerField()
+    meeting_title = serializers.CharField()
+    scheduled_at = serializers.CharField()
+    target_section = serializers.IntegerField()
+    target_section_label = serializers.CharField()
+    group_name = serializers.CharField()
+    hours_until = serializers.IntegerField()
+    ebook_id = serializers.IntegerField()
+    ebook_title = serializers.CharField()

backend/apps/groups/services/pace.py

@@ -0,0 +1,219 @@
+"""Pace calculation service for reading progress vs meeting targets."""
+
+from __future__ import annotations
+
+import logging
+from datetime import datetime, timedelta
+from typing import TypedDict
+
+from django.db.models import QuerySet
+from django.utils import timezone
+
+from apps.books.models import EBook, ReadingProgress
+from apps.groups.models import (
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    NotificationStatus,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class PaceStatus(TypedDict):
+    meeting_id: int
+    meeting_title: str
+    scheduled_at: str
+    target_section: int
+    target_section_label: str
+    current_section: int
+    ahead_behind_delta: int
+    status: str  # "ahead", "behind", "on_track", "completed"
+    days_until_meeting: int
+    sections_to_catch_up: int
+    ebook_id: int
+    ebook_title: str
+
+
+def get_relevant_ebooks_for_user(user) -> QuerySet[EBook]:
+    """Return ebooks that belong to groups the user is a member of."""
+    group_ids = (
+        GroupMembership.objects.filter(user=user)
+        .values_list("group_id", flat=True)
+    )
+    return (
+        EBook.objects.filter(reading_groups__in=group_ids)
+        .select_related("reading_progress")
+        .prefetch_related("chapters")
+        .distinct()
+    )
+
+
+def calculate_pace(
+    user,
+    ebook: EBook | None = None,
+    meeting: GroupMeeting | None = None,
+) -> list[PaceStatus]:
+    """Calculate reading pace for a user's upcoming meetings.
+
+    Compares the user's current reading progress (chapter index) against
+    the target section for each upcoming meeting within 3 days.
+    """
+    now = timezone.now()
+    three_days_from_now = now + timedelta(days=3)
+
+    # Find upcoming meetings for groups the user belongs to
+    user_group_ids = (
+        GroupMembership.objects.filter(user=user)
+        .values_list("group_id", flat=True)
+    )
+    meetings_qs = GroupMeeting.objects.filter(
+        group_id__in=user_group_ids,
+        scheduled_at__gte=now,
+        scheduled_at__lte=three_days_from_now,
+    ).select_related("group", "group__ebook")
+
+    if meeting:
+        meetings_qs = meetings_qs.filter(pk=meeting.pk)
+
+    meetings = list(meetings_qs)
+
+    results: list[PaceStatus] = []
+
+    for m in meetings:
+        group_ebook = m.group.ebook
+        ebooks_to_check: list[EBook] = []
+
+        if ebook:
+            ebooks_to_check = [ebook]
+        elif group_ebook:
+            ebooks_to_check = [group_ebook]
+        else:
+            # Check all ebooks in the group
+            ebooks_to_check = list(
+                EBook.objects.filter(reading_groups=m.group)
+                .select_related("reading_progress")
+                .prefetch_related("chapters")
+            )
+
+        for eb in ebooks_to_check:
+            pace = _compute_single_pace(user, m, eb, now)
+            if pace:
+                results.append(pace)
+
+    return results
+
+
+def _compute_single_pace(
+    user,
+    meeting: GroupMeeting,
+    ebook: EBook,
+    now: datetime,
+) -> PaceStatus | None:
+    """Compute pace for one user + meeting + ebook combination."""
+    try:
+        progress = ebook.reading_progress
+    except ReadingProgress.DoesNotExist:
+        # No progress yet — user hasn't started reading
+        return None
+
+    # Current section: based on last_page (chapter index) or computed from progress %
+    if progress.last_page > 0:
+        current_section = progress.last_page
+    elif progress.current_position > 0:
+        chapter_count = ebook.chapters.count() or ebook.page_count or 1
+        current_section = max(1, int((progress.current_position / 100) * chapter_count))
+    else:
+        current_section = 0
+
+    target_section = meeting.target_section or 0
+    if target_section == 0:
+        return None
+
+    delta = current_section - target_section
+    days_until = max(0, (meeting.scheduled_at - now).days)
+
+    if current_section >= target_section:
+        if current_section >= target_section and progress.current_position > 0:
+            status = "completed"
+        else:
+            status = "ahead"
+    elif delta >= -1:
+        status = "on_track"
+    else:
+        status = "behind"
+
+    return PaceStatus(
+        meeting_id=meeting.pk,
+        meeting_title=meeting.title or meeting.target_section_label,
+        scheduled_at=meeting.scheduled_at.isoformat(),
+        target_section=target_section,
+        target_section_label=meeting.target_section_label,
+        current_section=current_section,
+        ahead_behind_delta=delta,
+        status=status,
+        days_until_meeting=days_until,
+        sections_to_catch_up=max(0, target_section - current_section),
+        ebook_id=ebook.pk,
+        ebook_title=ebook.title,
+    )
+
+
+def should_send_notification(
+    user,
+    meeting: GroupMeeting,
+    ebook: EBook,
+) -> bool:
+    """Check if a pace notification should be sent based on user preferences."""
+    pref, _ = NotificationPreference.objects.get_or_create(user=user)
+
+    if not pref.pace_notifications_enabled:
+        return False
+
+    # Check if notification was already sent today
+    today = timezone.now().date()
+    existing = PaceNotification.objects.filter(
+        user=user,
+        meeting=meeting,
+        ebook=ebook,
+        created_at__date=today,
+    ).exclude(status=NotificationStatus.DISMISSED)
+
+    if existing.exists():
+        return False
+
+    # Frequency check
+    if pref.frequency == "weekly":
+        week_ago = today - timedelta(days=7)
+        recent = PaceNotification.objects.filter(
+            user=user,
+            meeting=meeting,
+            ebook=ebook,
+            created_at__date__gte=week_ago,
+        ).exclude(status=NotificationStatus.DISMISSED)
+        if recent.exists():
+            return False
+
+    return True
+
+
+def get_reminder_meetings(user) -> list[GroupMeeting]:
+    """Get meetings that are within 24 hours for reminder notifications."""
+    now = timezone.now()
+    tomorrow = now + timedelta(days=1)
+
+    user_group_ids = (
+        GroupMembership.objects.filter(user=user)
+        .values_list("group_id", flat=True)
+    )
+
+    return list(
+        GroupMeeting.objects.filter(
+            group_id__in=user_group_ids,
+            scheduled_at__gte=now,
+            scheduled_at__lte=tomorrow,
+        )
+        .select_related("group", "group__ebook")
+        .order_by("scheduled_at")
+    )

backend/apps/groups/urls.py

@@ -0,0 +1,23 @@
+from django.urls import include, path
+from rest_framework.routers import DefaultRouter
+
+from apps.groups.views import (
+    GroupMeetingViewSet,
+    ReadingGroupViewSet,
+    dismiss_pace_notification_view,
+    notification_preferences_view,
+    pace_status_view,
+    reminder_view,
+)
+
+router = DefaultRouter()
+router.register(r"groups", ReadingGroupViewSet, basename="reading-group")
+router.register(r"meetings", GroupMeetingViewSet, basename="group-meeting")
+
+urlpatterns = [
+    path("", include(router.urls)),
+    path("notifications/preferences/", notification_preferences_view, name="notification-preferences"),
+    path("notifications/pace/", pace_status_view, name="pace-status"),
+    path("notifications/dismiss/", dismiss_pace_notification_view, name="dismiss-pace"),
+    path("notifications/reminders/", reminder_view, name="meeting-reminders"),
+]

backend/apps/groups/views.py

@@ -0,0 +1,207 @@
+from __future__ import annotations
+
+from django.db.models import QuerySet
+from rest_framework import permissions, status, viewsets
+from rest_framework.decorators import action, api_view, permission_classes
+from rest_framework.permissions import IsAuthenticated
+from rest_framework.request import Request
+from rest_framework.response import Response
+
+from apps.books.models import EBook
+from apps.groups.models import (
+    GroupMeeting,
+    GroupMembership,
+    NotificationPreference,
+    PaceNotification,
+    NotificationStatus,
+    ReadingGroup,
+)
+from apps.groups.serializers import (
+    GroupMeetingSerializer,
+    GroupMembershipSerializer,
+    NotificationPreferenceSerializer,
+    PaceNotificationSerializer,
+    PaceStatusSerializer,
+    ReadingGroupSerializer,
+    ReminderSerializer,
+)
+from apps.groups.services.pace import (
+    calculate_pace,
+    get_reminder_meetings,
+    should_send_notification,
+)
+
+
+class IsGroupMember(permissions.BasePermission):
+    """Only allow group members to access group resources."""
+
+    def has_object_permission(self, request: Request, view: object, obj: ReadingGroup) -> bool:
+        return obj.memberships.filter(user=request.user).exists()
+
+
+class ReadingGroupViewSet(viewsets.ModelViewSet):
+    permission_classes = [IsAuthenticated, IsGroupMember]
+    serializer_class = ReadingGroupSerializer
+
+    def get_queryset(self) -> QuerySet[ReadingGroup]:
+        return (
+            ReadingGroup.objects.filter(memberships__user=self.request.user)
+            .prefetch_related("memberships", "meetings")
+            .distinct()
+        )
+
+    def perform_create(self, serializer) -> None:
+        group = serializer.save(created_by=self.request.user)
+        GroupMembership.objects.create(
+            user=self.request.user,
+            group=group,
+            role="admin",
+        )
+
+    @action(detail=False, methods=["get"], url_path="all")
+    def all_groups(self, request: Request) -> Response:
+        """Return all groups (for discovery)."""
+        qs = ReadingGroup.objects.all().prefetch_related("memberships", "meetings")
+        page = self.paginate_queryset(qs)
+        if page is not None:
+            serializer = self.get_serializer(page, many=True)
+            return self.get_paginated_response(serializer.data)
+        serializer = self.get_serializer(qs, many=True)
+        return Response(serializer.data)
+
+
+class GroupMeetingViewSet(viewsets.ModelViewSet):
+    permission_classes = [IsAuthenticated]
+    serializer_class = GroupMeetingSerializer
+
+    def get_queryset(self) -> QuerySet[GroupMeeting]:
+        user_group_ids = (
+            GroupMembership.objects.filter(user=self.request.user)
+            .values_list("group_id", flat=True)
+        )
+        return GroupMeeting.objects.filter(group_id__in=user_group_ids).select_related(
+            "group"
+        )
+
+    def perform_create(self, serializer) -> None:
+        group = serializer.validated_data["group"]
+        if not group.memberships.filter(user=self.request.user).exists():
+            raise permissions.PermissionDenied("You must be a group member to create meetings.")
+        serializer.save()
+
+    @action(detail=False, methods=["get"], url_path="upcoming")
+    def upcoming(self, request: Request) -> Response:
+        """Return upcoming meetings for the user's groups (within 3 days)."""
+        from django.utils import timezone
+        from datetime import timedelta
+
+        now = timezone.now()
+        three_days = now + timedelta(days=3)
+        qs = self.get_queryset().filter(
+            scheduled_at__gte=now,
+            scheduled_at__lte=three_days,
+        )
+        serializer = self.get_serializer(qs, many=True)
+        return Response(serializer.data)
+
+
+@api_view(["GET", "PATCH"])
+@permission_classes([IsAuthenticated])
+def notification_preferences_view(request: Request) -> Response:
+    """Get or update notification preferences for the current user."""
+    pref, _created = NotificationPreference.objects.get_or_create(user=request.user)
+
+    if request.method == "GET":
+        serializer = NotificationPreferenceSerializer(pref)
+        return Response(serializer.data)
+
+    serializer = NotificationPreferenceSerializer(pref, data=request.data, partial=True)
+    serializer.is_valid(raise_exception=True)
+    serializer.save()
+    return Response(serializer.data)
+
+
+@api_view(["GET"])
+@permission_classes([IsAuthenticated])
+def pace_status_view(request: Request) -> Response:
+    """Get reading pace status for the current user's upcoming meetings."""
+    ebook_id = request.query_params.get("ebook_id")
+    ebook: EBook | None = None
+
+    if ebook_id:
+        try:
+            ebook = EBook.objects.select_related("reading_progress").prefetch_related("chapters").get(
+                pk=ebook_id, user=request.user
+            )
+        except EBook.DoesNotExist:
+            return Response(
+                {"error": "EBook not found."}, status=status.HTTP_404_NOT_FOUND
+            )
+
+    pace_data = calculate_pace(request.user, ebook=ebook)
+    serializer = PaceStatusSerializer(pace_data, many=True)
+    return Response(serializer.data)
+
+
+@api_view(["POST"])
+@permission_classes([IsAuthenticated])
+def dismiss_pace_notification_view(request: Request) -> Response:
+    """Dismiss a pace notification so it won't show again."""
+    meeting_id = request.data.get("meeting_id")
+    ebook_id = request.data.get("ebook_id")
+
+    if not meeting_id or not ebook_id:
+        return Response(
+            {"error": "meeting_id and ebook_id are required."},
+            status=status.HTTP_400_BAD_REQUEST,
+        )
+
+    PaceNotification.objects.filter(
+        user=request.user,
+        meeting_id=meeting_id,
+        ebook_id=ebook_id,
+        status=NotificationStatus.PENDING,
+    ).update(status=NotificationStatus.DISMISSED)
+
+    return Response({"status": "dismissed"})
+
+
+@api_view(["GET"])
+@permission_classes([IsAuthenticated])
+def reminder_view(request: Request) -> Response:
+    """Get pre-meeting reminders for meetings within 24 hours."""
+    pref, _ = NotificationPreference.objects.get_or_create(user=request.user)
+    if not pref.reminder_enabled:
+        return Response([])
+
+    meetings = get_reminder_meetings(request.user)
+    now_dt = __import__("django").utils.timezone.now()
+
+    reminders = []
+    for mtg in meetings:
+        group_ebook = mtg.group.ebook
+        ebook: EBook | None = group_ebook
+        if not ebook:
+            ebooks = list(
+                EBook.objects.filter(reading_groups=mtg.group).select_related("reading_progress")[:1]
+            )
+            ebook = ebooks[0] if ebooks else None
+
+        if not ebook:
+            continue
+
+        hours_until = max(0, int((mtg.scheduled_at - now_dt).total_seconds() / 3600))
+        reminders.append({
+            "meeting_id": mtg.pk,
+            "meeting_title": mtg.title or mtg.target_section_label,
+            "scheduled_at": mtg.scheduled_at.isoformat(),
+            "target_section": mtg.target_section,
+            "target_section_label": mtg.target_section_label,
+            "group_name": mtg.group.name,
+            "hours_until": hours_until,
+            "ebook_id": ebook.pk,
+            "ebook_title": ebook.title,
+        })
+
+    serializer = ReminderSerializer(reminders, many=True)
+    return Response(serializer.data)

backend/config/django.py

@@ -41,6 +41,7 @@ INSTALLED_APPS = [
     "apps.books",
     "apps.annotations",
     "apps.reader",
+    "apps.groups",
 ]
 
 MIDDLEWARE = [

backend/config/urls.py

@@ -8,6 +8,7 @@ urlpatterns = [
     path("api/books/", include("apps.books.urls")),
     path("api/annotations/", include("apps.annotations.urls")),
     path("api/reader/", include("apps.reader.urls")),
+    path("api/groups/", include("apps.groups.urls")),
 ]
 
 if settings.DEBUG:

frontend/src/api/groups.ts

@@ -0,0 +1,57 @@
+import api from "./client";
+import type {
+  GroupMeeting,
+  MeetingReminder,
+  NotificationPreferences,
+  PaceStatus,
+  ReadingGroup,
+} from "../types/notifications";
+
+export const groupsApi = {
+  async getPaceStatus(ebookId?: number): Promise<PaceStatus[]> {
+    const params: Record<string, string> = {};
+    if (ebookId) params.ebook_id = String(ebookId);
+    const { data } = await api.get<PaceStatus[]>("/groups/notifications/pace/", { params });
+    return data;
+  },
+
+  async getPreferences(): Promise<NotificationPreferences> {
+    const { data } = await api.get<NotificationPreferences>("/groups/notifications/preferences/");
+    return data;
+  },
+
+  async updatePreferences(
+    prefs: Partial<NotificationPreferences>,
+  ): Promise<NotificationPreferences> {
+    const { data } = await api.patch<NotificationPreferences>(
+      "/groups/notifications/preferences/",
+      prefs,
+    );
+    return data;
+  },
+
+  async dismissPaceNotification(meetingId: number, ebookId: number): Promise<void> {
+    await api.post("/groups/notifications/dismiss/", {
+      meeting_id: meetingId,
+      ebook_id: ebookId,
+    });
+  },
+
+  async getReminders(): Promise<MeetingReminder[]> {
+    const { data } = await api.get<MeetingReminder[]>("/groups/notifications/reminders/");
+    return data;
+  },
+
+  async getGroups(): Promise<ReadingGroup[]> {
+    const { data } = await api.get<{ count: number; results: ReadingGroup[] } | ReadingGroup[]>(
+      "/groups/groups/",
+    );
+    if (Array.isArray(data)) return data;
+    return data.results ?? [];
+  },
+
+  async getUpcomingMeetings(): Promise<GroupMeeting[]> {
+    const { data } = await api.get<GroupMeeting[]>("/groups/meetings/upcoming/");
+    return data;
+  },
+};

frontend/src/components/notifications/PaceNotification.tsx

@@ -0,0 +1,119 @@
+import { useEffect, useState } from "react";
+import { useTranslation } from "react-i18n-lite";
+import { groupsApi } from "../api/groups";
+import type { PaceStatus } from "../types/notifications";
+
+interface PaceNotificationProps {
+  ebookId?: number;
+}
+
+export function PaceNotification({ ebookId }: PaceNotificationProps) {
+  const { t } = useTranslation();
+  const [paceItems, setPaceItems] = useState<PaceStatus[]>([]);
+  const [loading, setLoading] = useState(true);
+  const [dismissed, setDismissed] = useState<Set<string>>(new Set());
+
+  useEffect(() => {
+    const load = async () => {
+      try {
+        const data = await groupsApi.getPaceStatus(ebookId);
+        setPaceItems(data);
+      } catch {
+        // Silently fail — notifications are non-critical
+      } finally {
+        setLoading(false);
+      }
+    };
+    void load();
+  }, [ebookId]);
+
+  const handleDismiss = async (meetingId: number, itemEbookId: number) => {
+    const key = `${meetingId}-${itemEbookId}`;
+    setDismissed((prev) => new Set(prev).add(key));
+    try {
+      await groupsApi.dismissPaceNotification(meetingId, itemEbookId);
+    } catch {
+      // Best effort dismissal
+    }
+  };
+
+  if (loading || paceItems.length === 0) return null;
+
+  const visibleItems = paceItems.filter(
+    (p) => !dismissed.has(`${p.meeting_id}-${p.ebook_id}`),
+  );
+  if (visibleItems.length === 0) return null;
+
+  return (
+    <div style={{ display: "flex", flexDirection: "column", gap: 8, padding: "12px 0" }}>
+      {visibleItems.map((item) => {
+        const isBehind = item.status === "behind";
+        const isAhead = item.status === "ahead" || item.status === "completed";
+        const isOnTrack = item.status === "on_track";
+
+        const bgColor = isBehind ? "#fde8e8" : isAhead ? "#d4edda" : "#e8f4fd";
+        const borderColor = isBehind ? "#e74c3c" : isAhead ? "#27ae60" : "#3498db";
+        const textColor = isBehind ? "#a71d2a" : isAhead ? "#155724" : "#0c5460";
+
+        return (
+          <div
+            key={`${item.meeting_id}-${item.ebook_id}`}
+            style={{
+              background: bgColor,
+              border: `1px solid ${borderColor}`,
+              borderRadius: 8,
+              padding: "12px 16px",
+              display: "flex",
+              alignItems: "flex-start",
+              justifyContent: "space-between",
+              gap: 12,
+            }}
+          >
+            <div style={{ flex: 1 }}>
+              <div style={{ fontSize: 14, fontWeight: 600, color: textColor, marginBottom: 4 }}>
+                {isBehind
+                  ? `Behind schedule — catch up ${item.sections_to_catch_up} section${item.sections_to_catch_up !== 1 ? "s" : ""}`
+                  : isOnTrack
+                    ? "On track — keep going!"
+                    : item.status === "completed"
+                      ? "Meeting target completed!"
+                      : "Ahead of schedule — great job!"}
+              </div>
+              <div style={{ fontSize: 13, color: textColor, opacity: 0.85 }}>
+                {item.meeting_title || `Target: ${item.target_section_label || `Section ${item.target_section}`}`}
+                {" — "}
+                {item.ebook_title}
+              </div>
+              <div style={{ fontSize: 12, color: textColor, opacity: 0.7, marginTop: 2 }}>
+                {isBehind
+                  ? `Currently at section ${item.current_section}, need section ${item.target_section}`
+                  : `Section ${item.current_section} of ${item.target_section}`}
+                {item.days_until_meeting > 0 &&
+                  ` · ${item.days_until_meeting} day${item.days_until_meeting !== 1 ? "s" : ""} until meeting`}
+                {item.days_until_meeting === 0 && " · Meeting today"}
+              </div>
+            </div>
+            <button
+              type="button"
+              onClick={() => handleDismiss(item.meeting_id, item.ebook_id)}
+              style={{
+                background: "none",
+                border: "none",
+                color: textColor,
+                fontSize: 20,
+                cursor: "pointer",
+                padding: "0 4px",
+                lineHeight: 1,
+                opacity: 0.6,
+                flexShrink: 0,
+              }}
+              title="Dismiss"
+            >
+              ×
+            </button>
+          </div>
+        );
+      })}
+    </div>
+  );
+}

frontend/src/components/notifications/ReadingPaceBanner.tsx

@@ -0,0 +1,71 @@
+import { useEffect, useState } from "react";
+import { groupsApi } from "../../api/groups";
+import type { PaceStatus } from "../../types/notifications";
+
+interface ReadingPaceBannerProps {
+  ebookId: number;
+  currentSection: number;
+}
+
+export function ReadingPaceBanner({ ebookId, currentSection }: ReadingPaceBannerProps) {
+  const [paceItems, setPaceItems] = useState<PaceStatus[]>([]);
+
+  useEffect(() => {
+    const load = async () => {
+      try {
+        const data = await groupsApi.getPaceStatus(ebookId);
+        setPaceItems(data);
+      } catch {
+        // Silently fail
+      }
+    };
+    void load();
+  }, [ebookId, currentSection]);
+
+  if (paceItems.length === 0) return null;
+
+  // Only show if user is one section away from target
+  const relevantItems = paceItems.filter(
+    (p) => Math.abs(p.target_section - p.current_section) <= 1 && p.status !== "completed",
+  );
+
+  if (relevantItems.length === 0) return null;
+
+  return (
+    <div
+      style={{
+        background: "linear-gradient(135deg, #667eea 0%, #764ba2 100%)",
+        color: "#fff",
+        padding: "10px 16px",
+        fontSize: 13,
+        fontWeight: 500,
+        textAlign: "center",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+        gap: 8,
+        flexWrap: "wrap",
+        position: "sticky",
+        top: 0,
+        zIndex: 10,
+      }}
+    >
+      {relevantItems.map((item) => {
+        const isAlmostThere = item.sections_to_catch_up === 1;
+        const isAtTarget = item.sections_to_catch_up === 0;
+
+        return (
+          <span key={item.meeting_id}>
+            {isAtTarget
+              ? `You've reached the target for ${item.meeting_title || `Section ${item.target_section}`}!`
+              : isAlmostThere
+                ? `Almost there! Just 1 section to go for ${item.meeting_title || `Section ${item.target_section}`}.`
+                : `You should be on ${item.target_section_label || `Section ${item.target_section}`} by the upcoming meeting.`}
+            {item.days_until_meeting > 0 &&
+              ` (${item.days_until_meeting} day${item.days_until_meeting !== 1 ? "s" : ""} left)`}
+          </span>
+        );
+      })}
+    </div>
+  );
+}

frontend/src/components/reader/EpubReadingView.tsx

@@ -22,6 +22,7 @@ import { SelectionPopover } from "./SelectionPopover";
 import { BookMarkersPanel } from "./BookMarkersPanel";
 import { BookmarkReaderRail } from "./BookmarkReaderRail";
 import { ResumeReadingButton } from "./ResumeReadingButton";
+import { ReadingPaceBanner } from "../notifications/ReadingPaceBanner";
 import type { MarkerEntry } from "@/types";
 
 const ReaderToolbar = lazy(() => import("./ReaderToolbar"));
@@ -130,6 +131,10 @@ export function EpubReadingView({ book, bookId, initialEpubLocation }: EpubReadi
 
   return (
     <ReaderSuspenseShell theme={settings.theme}>
+        <ReadingPaceBanner
+          ebookId={bookId}
+          currentSection={tocItems.length > 0 ? Math.max(1, Math.ceil((progress / 100) * tocItems.length)) : 0}
+        />
         <ReaderToolbar
           bookTitle={book.title}
           chapterTitle={chapterTitle || t("reader.reading")}

frontend/src/components/reader/PdfReadingView.tsx

@@ -24,6 +24,7 @@ import { BookmarkReaderRail } from "./BookmarkReaderRail";
 import { ResumeReadingButton } from "./ResumeReadingButton";
 import { PdfLimitationsNotice } from "./PdfLimitationsNotice";
 import { PdfViewer } from "./PdfViewer";
+import { ReadingPaceBanner } from "../notifications/ReadingPaceBanner";
 import type { MarkerEntry } from "@/types";
 
 const ReaderToolbar = lazy(() => import("./ReaderToolbar"));
@@ -170,6 +171,10 @@ export function PdfReadingView({ book, bookId, initialAnchor }: PdfReadingViewPr
 
   return (
     <ReaderSuspenseShell theme={settings.theme}>
+        <ReadingPaceBanner
+          ebookId={bookId}
+          currentSection={currentPage}
+        />
         <ReaderToolbar
           bookTitle={book.title}
           chapterTitle={chapterTitle || t("reader.reading")}

frontend/src/pages/Library.tsx

@@ -19,6 +19,7 @@ import { useVoiceSearch } from "../hooks/useVoiceSearch";
 import { useMediaQuery, BREAKPOINTS } from "../hooks/useMediaQuery";
 import { SearchSuggestions } from "../components/search/SearchSuggestions";
 import { BookContextMenu } from "../components/BookContextMenu";
+import { PaceNotification } from "../components/notifications/PaceNotification";
 
 interface FilterState {
   genre: string;
@@ -256,6 +257,9 @@ export function LibraryPage() {
         </div>
       </header>
 
+      {/* Pace Notifications */}
+      <PaceNotification />
+
       {/* Search Bar */}
       <div style={{ marginBottom: 16 }}>
         <div style={{ display: "flex", gap: 8, alignItems: "center" }}>

frontend/src/pages/Settings.tsx

@@ -2,7 +2,9 @@ import { useEffect, useState } from "react";
 import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18n-lite";
 import { booksApi } from "../api/books";
+import { groupsApi } from "../api/groups";
 import type { ReadingSettings } from "../types/book";
+import type { NotificationPreferences } from "../types/notifications";
 import type { SupportedLanguage } from "../locales";
 import { SimpleFormPageLayout } from "../components/layout/SimpleFormPageLayout";
 
@@ -17,6 +19,7 @@ export function SettingsPage() {
   const { t, language, setLanguage } = useTranslation();
   const navigate = useNavigate();
   const [settings, setSettings] = useState<ReadingSettings | null>(null);
+  const [notifPrefs, setNotifPrefs] = useState<NotificationPreferences | null>(null);
   const [loading, setLoading] = useState(true);
   const [saving, setSaving] = useState(false);
   const [error, setError] = useState<string | null>(null);
@@ -24,7 +27,14 @@ export function SettingsPage() {
 
   useEffect(() => {
     const load = async () => {
-      try { const data = await booksApi.getSettings(); setSettings(data); }
+      try {
+        const [data, notifData] = await Promise.all([
+          booksApi.getSettings(),
+          groupsApi.getPreferences(),
+        ]);
+        setSettings(data);
+        setNotifPrefs(notifData);
+      }
       catch (err) { setError(err instanceof Error ? err.message : t("settings.loadFailed")); }
       finally { setLoading(false); }
     };
@@ -32,9 +42,15 @@ export function SettingsPage() {
   }, [t]);
 
   const handleSave = async () => {
-    if (!settings) return;
+    if (!settings || !notifPrefs) return;
     setSaving(true); setError(null); setSuccess(false);
-    try { await booksApi.updateSettings(settings); setSuccess(true); setTimeout(() => setSuccess(false), 2000); }
+    try {
+      await Promise.all([
+        booksApi.updateSettings(settings),
+        groupsApi.updatePreferences(notifPrefs),
+      ]);
+      setSuccess(true); setTimeout(() => setSuccess(false), 2000);
+    }
     catch (err) { setError(err instanceof Error ? err.message : t("settings.saveFailed")); }
     finally { setSaving(false); }
   };
@@ -85,6 +101,48 @@ export function SettingsPage() {
           </div>
         </>}
 
+        {notifPrefs && <>
+          <div style={{ borderTop: "1px solid #e5e7eb", paddingTop: 20 }}>
+            <h3 style={{ fontSize: 16, fontWeight: 600, color: "#1f2937", marginBottom: 16 }}>
+              Notification Settings
+            </h3>
+
+            <div style={{ display: "flex", flexDirection: "column", gap: 12 }}>
+              <label style={{ display: "flex", alignItems: "center", gap: 10, fontSize: 14, color: "#374151", cursor: "pointer" }}>
+                <input
+                  type="checkbox"
+                  checked={notifPrefs.pace_notifications_enabled}
+                  onChange={(e) => setNotifPrefs({ ...notifPrefs, pace_notifications_enabled: e.target.checked })}
+                  style={{ width: 18, height: 18, cursor: "pointer" }}
+                />
+                Enable pace notifications
+              </label>
+
+              <label style={{ display: "flex", alignItems: "center", gap: 10, fontSize: 14, color: "#374151", cursor: "pointer" }}>
+                <input
+                  type="checkbox"
+                  checked={notifPrefs.reminder_enabled}
+                  onChange={(e) => setNotifPrefs({ ...notifPrefs, reminder_enabled: e.target.checked })}
+                  style={{ width: 18, height: 18, cursor: "pointer" }}
+                />
+                Enable pre-meeting reminders (24h before)
+              </label>
+
+              <div style={{ display: "flex", flexDirection: "column", gap: 8 }}>
+                <label style={{ fontSize: 14, fontWeight: 600, color: "#555" }}>Notification frequency</label>
+                <select
+                  value={notifPrefs.frequency}
+                  onChange={(e) => setNotifPrefs({ ...notifPrefs, frequency: e.target.value as NotificationPreferences["frequency"] })}
+                  style={{ padding: "10px 12px", borderRadius: 6, border: "1px solid #ddd", fontSize: 16, background: "#fff", outline: "none" }}
+                >
+                  <option value="daily">Daily</option>
+                  <option value="weekly">Weekly</option>
+                </select>
+              </div>
+            </div>
+          </div>
+        </>}
+
         <button onClick={handleSave} disabled={saving} style={{ padding: "12px 24px", borderRadius: 8, border: "none", background: "#1a1a2e", color: "#fff", fontSize: 16, fontWeight: 600, cursor: "pointer", opacity: saving ? 0.6 : 1, marginTop: 8 }}>{saving ? t("common.saving") : t("settings.saveSettings")}</button>
       </div>
     </SimpleFormPageLayout>

frontend/src/types/notifications.ts

@@ -0,0 +1,65 @@
+export interface PaceStatus {
+  meeting_id: number;
+  meeting_title: string;
+  scheduled_at: string;
+  target_section: number;
+  target_section_label: string;
+  current_section: number;
+  ahead_behind_delta: number;
+  status: "ahead" | "behind" | "on_track" | "completed";
+  days_until_meeting: number;
+  sections_to_catch_up: number;
+  ebook_id: number;
+  ebook_title: string;
+}
+
+export interface NotificationPreferences {
+  pace_notifications_enabled: boolean;
+  reminder_enabled: boolean;
+  frequency: "daily" | "weekly";
+}
+
+export interface MeetingReminder {
+  meeting_id: number;
+  meeting_title: string;
+  scheduled_at: string;
+  target_section: number;
+  target_section_label: string;
+  group_name: string;
+  hours_until: number;
+  ebook_id: number;
+  ebook_title: string;
+}
+
+export interface ReadingGroup {
+  id: number;
+  name: string;
+  description: string;
+  book: number | null;
+  ebook: number | null;
+  created_by: number;
+  created_at: string;
+  member_count: number;
+  meeting_count: number;
+}
+
+export interface GroupMeeting {
+  id: number;
+  group: number;
+  group_name: string;
+  title: string;
+  scheduled_at: string;
+  target_section: number;
+  target_section_label: string;
+  created_at: string;
+}
+
+export interface GroupMembership {
+  id: number;
+  user: number;
+  user_email: string;
+  group: number;
+  group_name: string;
+  role: "admin" | "member";
+  joined_at: string;
+}