refactor: add CardBase and ModalBase components

- Add CardBase: reusable card with header, content, footer
  - Configurable via props: padding, border, text size, background
- Add ModalBase: modal wrapper using CardBase internally
  - Provides backdrop, click-outside-to-close, Android back button
- Refactor EventCardBase to use CardBase
- Refactor DeleteEventModal to use ModalBase
- Refactor EventOverlay (calendar.tsx) to use ModalBase
- Update CLAUDE.md with component documentation

CLAUDE.md

@@ -86,13 +86,15 @@ src/
 │   ├── BaseButton.tsx          # Reusable button component (themed, supports children)
 │   ├── Header.tsx              # Header component (themed)
 │   ├── AuthButton.tsx          # Reusable button for auth screens (themed, with shadow)
+│   ├── CardBase.tsx            # Reusable card component (header + content + optional footer)
+│   ├── ModalBase.tsx           # Reusable modal with backdrop (uses CardBase, click-outside-to-close)
 │   ├── ChatBubble.tsx          # Reusable chat bubble component (used by ChatMessage & TypingIndicator)
 │   ├── TypingIndicator.tsx     # Animated typing indicator (. .. ...) shown while waiting for AI response
-│   ├── EventCardBase.tsx       # Shared event card layout with icons (used by EventCard & ProposedEventCard)
+│   ├── EventCardBase.tsx       # Event card layout with icons (uses CardBase)
 │   ├── EventCard.tsx           # Calendar event card (uses EventCardBase + edit/delete buttons)
 │   ├── EventConfirmDialog.tsx  # AI-proposed event confirmation modal (skeleton)
 │   ├── ProposedEventCard.tsx   # Chat event proposal (uses EventCardBase + confirm/reject buttons)
-│   └── DeleteEventModal.tsx    # Unified delete confirmation modal (recurring: 3 options, non-recurring: simple confirm)
+│   └── DeleteEventModal.tsx    # Delete confirmation modal (uses ModalBase)
 ├── Themes.tsx                  # Theme definitions: THEMES object with defaultLight/defaultDark, Theme type
 ├── logging/
 │   ├── index.ts                # Re-exports
@@ -157,6 +159,58 @@ setTheme("defaultDark"); // or "defaultLight"
 
 **Note:** `shadowColor` only works on iOS. Android uses `elevation` with system-defined shadow colors.
 
+### Base Components (CardBase & ModalBase)
+
+Reusable base components for cards and modals with consistent styling.
+
+**CardBase** - Card structure with header, content, and optional footer:
+```typescript
+<CardBase
+  title="Title"
+  subtitle="Optional subtitle"
+  footer={{ label: "Button", onPress: () => {} }}
+  // Styling props (all optional):
+  headerPadding={4}           // p-{n}, default: px-3 py-2
+  contentPadding={4}          // p-{n}, default: px-3 py-2
+  headerTextSize="text-lg"    // "text-sm" | "text-base" | "text-lg" | "text-xl"
+  borderWidth={2}             // outer border, default: 2
+  headerBorderWidth={3}       // header bottom border, default: borderWidth
+  contentBg={theme.primeBg}   // content background color, default: theme.secondaryBg
+  scrollable={true}           // wrap content in ScrollView
+  maxContentHeight={400}      // for scrollable content
+>
+  {children}
+</CardBase>
+```
+
+**ModalBase** - Modal with backdrop using CardBase internally:
+```typescript
+<ModalBase
+  visible={isVisible}
+  onClose={() => setVisible(false)}
+  title="Modal Title"
+  subtitle="Optional"
+  footer={{ label: "Close", onPress: onClose }}
+  scrollable={true}
+  maxContentHeight={400}
+>
+  {children}
+</ModalBase>
+```
+
+ModalBase provides: transparent Modal + backdrop (click-outside-to-close) + Android back button support.
+
+**Component Hierarchy:**
+```
+CardBase
+├── ModalBase (uses CardBase)
+│   ├── DeleteEventModal
+│   └── EventOverlay (in calendar.tsx)
+└── EventCardBase (uses CardBase)
+    ├── EventCard
+    └── ProposedEventCard
+```
+
 ### Backend Architecture (apps/server)
 
 ```
@@ -461,10 +515,13 @@ NODE_ENV=development        # development = pretty logs, production = JSON
   - keyboardDismissMode="interactive" and keyboardShouldPersistTaps="handled"
 - `EventService`: getAll(), getById(), getByDateRange(), create(), update(), delete(mode, occurrenceDate) - fully implemented with recurring delete modes
 - `ChatService`: sendMessage(), confirmEvent(deleteMode, occurrenceDate), rejectEvent(), getConversations(), getConversation() - fully implemented with cursor pagination and recurring delete support
-- `EventCardBase`: Shared base component with event layout (header, date/time/recurring icons, description) - used by both EventCard and ProposedEventCard
+- `CardBase`: Reusable card component with header (title/subtitle), content area, and optional footer button - configurable padding, border, text size via props
+- `ModalBase`: Reusable modal wrapper with backdrop, uses CardBase internally - provides click-outside-to-close and Android back button support
+- `EventCardBase`: Event card with date/time/recurring icons - uses CardBase for structure
 - `EventCard`: Uses EventCardBase + edit/delete buttons for calendar display
 - `ProposedEventCard`: Uses EventCardBase + confirm/reject buttons for chat proposals (supports create/update/delete actions with deleteMode display)
-- `DeleteEventModal`: Unified delete confirmation modal - shows three options for recurring events (single/future/all), simple confirm for non-recurring
+- `DeleteEventModal`: Delete confirmation modal using ModalBase - shows three options for recurring events (single/future/all), simple confirm for non-recurring
+- `EventOverlay` (in calendar.tsx): Day events overlay using ModalBase - shows EventCards for selected day
 - `Themes.tsx`: Theme definitions with THEMES object (defaultLight, defaultDark) including all color tokens (textPrimary, borderPrimary, eventIndicator, secondaryBg, shadowColor, etc.)
 - `EventsStore`: Zustand store with setEvents(), addEvent(), updateEvent(), deleteEvent() - stores ExpandedEvent[]
 - `ChatStore`: Zustand store with addMessage(), addMessages(), updateMessage(), clearMessages(), isWaitingForResponse/setWaitingForResponse() for typing indicator - loads from server on mount and persists across tab switches

apps/client/src/app/(tabs)/calendar.tsx

@@ -1,11 +1,4 @@
-import {
+import { Animated, Modal, Pressable, Text, View } from "react-native";
-  Animated,
-  Modal,
-  Pressable,
-  Text,
-  View,
-  ScrollView,
-} from "react-native";
 import {
   DAYS,
   MONTHS,
@@ -16,6 +9,7 @@ import {
 import Header from "../../components/Header";
 import { EventCard } from "../../components/EventCard";
 import { DeleteEventModal } from "../../components/DeleteEventModal";
+import { ModalBase } from "../../components/ModalBase";
 import React, {
   useCallback,
   useEffect,
@@ -263,7 +257,6 @@ const EventOverlay = ({
   onEditEvent,
   onDeleteEvent,
 }: EventOverlayProps) => {
-  const { theme } = useThemeStore();
   if (!date) return null;
 
   const dateString = date.toLocaleDateString("de-DE", {
@@ -273,49 +266,18 @@ const EventOverlay = ({
     year: "numeric",
   });
 
-  return (
+  const subtitle = `${events.length} ${events.length === 1 ? "Termin" : "Termine"}`;
-    <Modal
-      visible={visible}
-      transparent={true}
-      animationType="fade"
-      onRequestClose={onClose}
-    >
-      <Pressable
-        className="flex-1 justify-center items-center"
-        style={{ backgroundColor: "rgba(0,0,0,0.5)" }}
-        onPress={onClose}
-      >
-        <Pressable
-          className="w-11/12 max-h-3/4 rounded-2xl overflow-hidden"
-          style={{
-            backgroundColor: theme.primeBg,
-            borderWidth: 4,
-            borderColor: theme.borderPrimary,
-          }}
-          onPress={(e) => e.stopPropagation()}
-        >
-          {/* Header */}
-          <View
-            className="px-4 py-3"
-            style={{
-              backgroundColor: theme.chatBot,
-              borderBottomWidth: 3,
-              borderBottomColor: theme.borderPrimary,
-            }}
-          >
-            <Text
-              className="font-bold text-lg"
-              style={{ color: theme.textPrimary }}
-            >
-              {dateString}
-            </Text>
-            <Text style={{ color: theme.textPrimary }}>
-              {events.length} {events.length === 1 ? "Termin" : "Termine"}
-            </Text>
-          </View>
 
-          {/* Events List */}
+  return (
-          <ScrollView className="p-4" style={{ maxHeight: 400 }}>
+    <ModalBase
+      visible={visible}
+      onClose={onClose}
+      title={dateString}
+      subtitle={subtitle}
+      footer={{ label: "Schliessen", onPress: onClose }}
+      scrollable={true}
+      maxContentHeight={400}
+    >
       {events.map((event, index) => (
         <EventCard
           key={`${event.id}-${index}`}
@@ -324,24 +286,7 @@ const EventOverlay = ({
           onDelete={() => onDeleteEvent(event)}
         />
       ))}
-          </ScrollView>
+    </ModalBase>
-
-          {/* Close button */}
-          <Pressable
-            onPress={onClose}
-            className="py-3 items-center"
-            style={{
-              borderTopWidth: 1,
-              borderTopColor: theme.placeholderBg,
-            }}
-          >
-            <Text style={{ color: theme.primeFg }} className="font-bold">
-              Schließen
-            </Text>
-          </Pressable>
-        </Pressable>
-      </Pressable>
-    </Modal>
   );
 };
 

apps/client/src/app/(tabs)/chat.tsx

@@ -114,9 +114,7 @@ const Chat = () => {
     const message = messages.find((m) => m.id === messageId);
     if (message?.proposedChanges) {
       const updatedProposals = message.proposedChanges.map((p) =>
-        p.id === proposalId
+        p.id === proposalId ? { ...p, respondedAction: action } : p,
-          ? { ...p, respondedAction: action }
-          : p,
       );
       updateMessage(messageId, { proposedChanges: updatedProposals });
     }

apps/client/src/components/CardBase.tsx

@@ -0,0 +1,113 @@
+import { View, Text, Pressable, ScrollView } from "react-native";
+import { ReactNode } from "react";
+import { useThemeStore } from "../stores/ThemeStore";
+
+type TextSize = "text-sm" | "text-base" | "text-lg" | "text-xl";
+
+type CardBaseProps = {
+  title: string;
+  subtitle?: string;
+  children: ReactNode;
+  footer?: {
+    label: string;
+    onPress: () => void;
+  };
+  className?: string;
+  scrollable?: boolean;
+  maxContentHeight?: number;
+  borderWidth?: number;
+  headerBorderWidth?: number;
+  headerPadding?: number;
+  contentPadding?: number;
+  headerTextSize?: TextSize;
+  contentBg?: string;
+};
+
+export const CardBase = ({
+  title,
+  subtitle,
+  children,
+  footer,
+  className = "",
+  scrollable = false,
+  maxContentHeight,
+  borderWidth = 2,
+  headerBorderWidth,
+  headerPadding,
+  contentPadding,
+  headerTextSize = "text-base",
+  contentBg,
+}: CardBaseProps) => {
+  const { theme } = useThemeStore();
+  const effectiveHeaderBorderWidth = headerBorderWidth ?? borderWidth;
+
+  const headerPaddingClass = headerPadding ? `p-${headerPadding}` : "px-3 py-2";
+  const contentPaddingClass = contentPadding
+    ? `p-${contentPadding}`
+    : "px-3 py-2";
+
+  const contentElement = (
+    <View
+      className={contentPaddingClass}
+      style={{ backgroundColor: contentBg ?? theme.secondaryBg }}
+    >
+      {children}
+    </View>
+  );
+
+  return (
+    <View
+      className={`rounded-xl overflow-hidden ${className}`}
+      style={{ borderWidth, borderColor: theme.borderPrimary }}
+    >
+      {/* Header */}
+      <View
+        className={headerPaddingClass}
+        style={{
+          backgroundColor: theme.chatBot,
+          borderBottomWidth: effectiveHeaderBorderWidth,
+          borderBottomColor: theme.borderPrimary,
+        }}
+      >
+        <Text
+          className={`font-bold ${headerTextSize}`}
+          style={{ color: theme.textPrimary }}
+        >
+          {title}
+        </Text>
+        {subtitle && (
+          <Text style={{ color: theme.primeFg }} numberOfLines={1}>
+            {subtitle}
+          </Text>
+        )}
+      </View>
+
+      {/* Content */}
+      {scrollable ? (
+        <ScrollView style={{ maxHeight: maxContentHeight }}>
+          {contentElement}
+        </ScrollView>
+      ) : (
+        contentElement
+      )}
+
+      {/* Footer (optional) */}
+      {footer && (
+        <Pressable
+          onPress={footer.onPress}
+          className="py-3 items-center"
+          style={{
+            borderTopWidth: 1,
+            borderTopColor: theme.placeholderBg,
+          }}
+        >
+          <Text style={{ color: theme.primeFg }} className="font-bold">
+            {footer.label}
+          </Text>
+        </Pressable>
+      )}
+    </View>
+  );
+};
+
+export default CardBase;

apps/client/src/components/DeleteEventModal.tsx

@@ -1,6 +1,7 @@
-import { Modal, Pressable, Text, View } from "react-native";
+import { Pressable, Text, View } from "react-native";
 import { RecurringDeleteMode } from "@calchat/shared";
 import { useThemeStore } from "../stores/ThemeStore";
+import { ModalBase } from "./ModalBase";
 
 type DeleteEventModalProps = {
   visible: boolean;
@@ -13,24 +14,20 @@ type DeleteEventModalProps = {
 type DeleteOption = {
   mode: RecurringDeleteMode;
   label: string;
-  description: string;
 };
 
 const RECURRING_DELETE_OPTIONS: DeleteOption[] = [
   {
     mode: "single",
     label: "Nur dieses Vorkommen",
-    description: "Nur der ausgewaehlte Termin wird entfernt",
   },
   {
     mode: "future",
-    label: "Dieses und zukuenftige",
+    label: "Dieses und zukünftige",
-    description: "Dieser und alle folgenden Termine werden entfernt",
   },
   {
     mode: "all",
     label: "Alle Vorkommen",
-    description: "Die gesamte Terminserie wird geloescht",
   },
 ];
 
@@ -43,51 +40,18 @@ export const DeleteEventModal = ({
 }: DeleteEventModalProps) => {
   const { theme } = useThemeStore();
 
-  return (
+  const title = isRecurring
-    <Modal
+    ? "Wiederkehrenden Termin löschen"
-      visible={visible}
+    : "Termin loeschen";
-      transparent={true}
-      animationType="fade"
-      onRequestClose={onCancel}
-    >
-      <Pressable
-        className="flex-1 justify-center items-center"
-        style={{ backgroundColor: "rgba(0,0,0,0.5)" }}
-        onPress={onCancel}
-      >
-        <Pressable
-          className="w-11/12 rounded-2xl overflow-hidden"
-          style={{
-            backgroundColor: theme.primeBg,
-            borderWidth: 4,
-            borderColor: theme.borderPrimary,
-          }}
-          onPress={(e) => e.stopPropagation()}
-        >
-          {/* Header */}
-          <View
-            className="px-4 py-3"
-            style={{
-              backgroundColor: theme.chatBot,
-              borderBottomWidth: 3,
-              borderBottomColor: theme.borderPrimary,
-            }}
-          >
-            <Text
-              className="font-bold text-lg"
-              style={{ color: theme.textPrimary }}
-            >
-              {isRecurring
-                ? "Wiederkehrenden Termin loeschen"
-                : "Termin loeschen"}
-            </Text>
-            <Text style={{ color: theme.textSecondary }} numberOfLines={1}>
-              {eventTitle}
-            </Text>
-          </View>
 
-          {/* Content */}
+  return (
-          <View className="p-4">
+    <ModalBase
+      visible={visible}
+      onClose={onCancel}
+      title={title}
+      subtitle={eventTitle}
+      footer={{ label: "Abbrechen", onPress: onCancel }}
+    >
       {isRecurring ? (
         // Recurring event: show three options
         RECURRING_DELETE_OPTIONS.map((option) => (
@@ -107,22 +71,13 @@ export const DeleteEventModal = ({
             >
               {option.label}
             </Text>
-                  <Text
-                    className="text-sm mt-1"
-                    style={{ color: theme.textMuted }}
-                  >
-                    {option.description}
-                  </Text>
           </Pressable>
         ))
       ) : (
         // Non-recurring event: simple confirmation
         <View>
-                <Text
+          <Text className="text-base mb-4" style={{ color: theme.textPrimary }}>
-                  className="text-base mb-4"
+            Moechtest du diesen Termin wirklich loeschen?
-                  style={{ color: theme.textPrimary }}
-                >
-                  Möchtest du diesen Termin wirklich löschen?
           </Text>
           <Pressable
             onPress={() => onConfirm("all")}
@@ -140,23 +95,6 @@ export const DeleteEventModal = ({
           </Pressable>
         </View>
       )}
-          </View>
+    </ModalBase>
-
-          {/* Cancel button */}
-          <Pressable
-            onPress={onCancel}
-            className="py-3 items-center"
-            style={{
-              borderTopWidth: 1,
-              borderTopColor: theme.placeholderBg,
-            }}
-          >
-            <Text style={{ color: theme.primeFg }} className="font-bold">
-              Abbrechen
-            </Text>
-          </Pressable>
-        </Pressable>
-      </Pressable>
-    </Modal>
   );
 };

apps/client/src/components/EventCardBase.tsx

@@ -2,6 +2,7 @@ import { View, Text } from "react-native";
 import { Feather } from "@expo/vector-icons";
 import { ReactNode } from "react";
 import { useThemeStore } from "../stores/ThemeStore";
+import { CardBase } from "./CardBase";
 
 type EventCardBaseProps = {
   className?: string;
@@ -61,33 +62,9 @@ export const EventCardBase = ({
   children,
 }: EventCardBaseProps) => {
   const { theme } = useThemeStore();
-  return (
-    <View
-      className={`rounded-xl overflow-hidden ${className}`}
-      style={{ borderWidth: 2, borderColor: theme.borderPrimary }}
-    >
-      {/* Header with title */}
-      <View
-        className="px-3 py-2"
-        style={{
-          backgroundColor: theme.chatBot,
-          borderBottomWidth: 2,
-          borderBottomColor: theme.borderPrimary,
-        }}
-      >
-        <Text
-          className="font-bold text-base"
-          style={{ color: theme.textPrimary }}
-        >
-          {title}
-        </Text>
-      </View>
 
-      {/* Content */}
+  return (
-      <View
+    <CardBase title={title} className={className} borderWidth={2}>
-        className="px-3 py-2"
-        style={{ backgroundColor: theme.secondaryBg }}
-      >
       {/* Date */}
       <View className="flex-row items-center mb-1">
         <Feather
@@ -137,8 +114,7 @@ export const EventCardBase = ({
 
       {/* Action buttons slot */}
       {children}
-      </View>
+    </CardBase>
-    </View>
   );
 };
 

apps/client/src/components/ModalBase.tsx

@@ -0,0 +1,74 @@
+import { Modal, Pressable } from "react-native";
+import { ReactNode } from "react";
+import { useThemeStore } from "../stores/ThemeStore";
+import { CardBase } from "./CardBase";
+
+type ModalBaseProps = {
+  visible: boolean;
+  onClose: () => void;
+  title: string;
+  subtitle?: string;
+  children: ReactNode;
+  footer?: {
+    label: string;
+    onPress: () => void;
+  };
+  scrollable?: boolean;
+  maxContentHeight?: number;
+};
+
+export const ModalBase = ({
+  visible,
+  onClose,
+  title,
+  subtitle,
+  children,
+  footer,
+  scrollable,
+  maxContentHeight,
+}: ModalBaseProps) => {
+  const { theme } = useThemeStore();
+
+  return (
+    <Modal
+      visible={visible}
+      transparent={true}
+      animationType="fade"
+      onRequestClose={onClose}
+    >
+      <Pressable
+        className="flex-1 justify-center items-center"
+        style={{ backgroundColor: "rgba(0,0,0,0.5)" }}
+        onPress={onClose}
+      >
+        <Pressable
+          className="w-11/12 rounded-2xl overflow-hidden"
+          style={{
+            backgroundColor: theme.primeBg,
+            borderWidth: 4,
+            borderColor: theme.borderPrimary,
+          }}
+          onPress={(e) => e.stopPropagation()}
+        >
+          <CardBase
+            title={title}
+            subtitle={subtitle}
+            footer={footer}
+            scrollable={scrollable}
+            maxContentHeight={maxContentHeight}
+            borderWidth={0}
+            headerBorderWidth={3}
+            headerPadding={4}
+            contentPadding={4}
+            headerTextSize="text-lg"
+            contentBg={theme.primeBg}
+          >
+            {children}
+          </CardBase>
+        </Pressable>
+      </Pressable>
+    </Modal>
+  );
+};
+
+export default ModalBase;