diff --git a/src/app/(main)/kunden/[id]/page.tsx b/src/app/(main)/kunden/[id]/page.tsx
index d488e26..aecbe12 100644
--- a/src/app/(main)/kunden/[id]/page.tsx
+++ b/src/app/(main)/kunden/[id]/page.tsx
@@ -1,6 +1,9 @@
 import { requireManager } from "@/src/lib/auth/getUser";
+import { getKundeDetail } from "@/src/modules/kunden/actions/kunde-detail-actions";
 import { ArrowLeft } from "lucide-react";
 import Link from "next/link";
+import { notFound } from "next/navigation";
+import KundeDetailView from "@/src/modules/kunden/ui/views/kunde-detail-view";
 
 interface Props {
   params: Promise<{ id: string }>;
@@ -10,17 +13,22 @@ const KundeDetailPage = async ({ params }: Props) => {
   await requireManager();
   const { id } = await params;
 
+  const result = await getKundeDetail(id);
+
+  if (!result.success) {
+    notFound();
+  }
+
   return (
     <div className="p-2">
       <Link
         href="/kunden"
-        className="inline-flex items-center gap-2 text-sm text-muted-foreground hover:text-foreground mb-6"
+        className="inline-flex items-center gap-2 text-sm text-muted-foreground hover:text-foreground mb-6 transition-colors"
       >
         <ArrowLeft size={16} />
         Zurück zur Übersicht
       </Link>
-      <h1 className="text-4xl font-bold mb-2">Kundendetails</h1>
-      <p className="text-muted-foreground text-sm">Kunde ID: {id}</p>
+      <KundeDetailView kunde={result.kunde} />
     </div>
   );
 };
diff --git a/src/components/ui/sidebar.tsx b/src/components/ui/sidebar.tsx
index fe4536f..4e39eac 100644
--- a/src/components/ui/sidebar.tsx
+++ b/src/components/ui/sidebar.tsx
@@ -187,7 +187,7 @@ function Sidebar({
           data-sidebar="sidebar"
           data-slot="sidebar"
           data-mobile="true"
-          className="bg-sidebar text-sidebar-foreground w-(--sidebar-width) p-0 [&>button]:hidden"
+          className="bg-white text-sidebar-foreground w-(--sidebar-width) p-0 [&>button]:hidden"
           style={
             {
               "--sidebar-width": SIDEBAR_WIDTH_MOBILE,
diff --git a/src/modules/courses/ui/components/PublicCourseCard.tsx b/src/modules/courses/ui/components/PublicCourseCard.tsx
index 57bf38c..4c9aa90 100644
--- a/src/modules/courses/ui/components/PublicCourseCard.tsx
+++ b/src/modules/courses/ui/components/PublicCourseCard.tsx
@@ -39,20 +39,20 @@ const levelConfig: Record<string, { label: string; bg: string; text: string }> =
   pro: { label: "Profi", bg: "bg-red-200", text: "text-red-700" },
 };
 
-interface TrainerProfile {
+export interface TrainerProfile {
   id: string;
   firstName: string | null;
   lastName: string | null;
   pbSrc: string | null;
 }
 
-interface BusinessInfo {
+export interface BusinessInfo {
   address: string;
   email: string;
   tel?: string;
 }
 
-interface PublicCourse {
+export interface PublicCourse {
   id: string;
   name: string;
   sport: string[];
@@ -102,22 +102,34 @@ const TrainerAvatar = ({ trainer, size }: { trainer: TrainerProfile; size: "sm"
   );
 };
 
-const BookingDialog = ({
+const ADMIN_PAYMENT_LABELS: Record<string, { label: string; bg: string; text: string }> = {
+  paid: { label: "Bezahlt", bg: "bg-green-100", text: "text-green-700" },
+  pending: { label: "Ausstehend", bg: "bg-yellow-100", text: "text-yellow-700" },
+  refunded: { label: "Storniert", bg: "bg-red-100", text: "text-red-600" },
+  failed: { label: "Fehlgeschlagen", bg: "bg-red-100", text: "text-red-600" },
+};
+
+export const BookingDialog = ({
   course,
   business,
   open,
   onOpenChange,
+  // Wenn gesetzt → Admin-Ansicht: kein Buchen-Button, nur Status-Badge
+  paymentStatus,
 }: {
   course: PublicCourse;
   business?: BusinessInfo;
   open: boolean;
   onOpenChange: (v: boolean) => void;
+  paymentStatus?: string;
 }) => {
   const sanitizedDescription = useSanitizedHtml(course.description);
   const [isSubmitting, setIsSubmitting] = useState(false);
   const [isBooked, setIsBooked] = useState(false);
   const [isCheckingStatus, setIsCheckingStatus] = useState(true);
 
+  const isAdminView = paymentStatus !== undefined;
+
   const safeCurrent = Math.max(0, course.currentParticipants);
   const safeMax = Math.max(0, course.maxParticipants);
   const isFull = safeCurrent >= safeMax;
@@ -134,8 +146,9 @@ const BookingDialog = ({
     currency: "EUR",
   });
 
+  // Booking-Status nur laden wenn keine Admin-Ansicht
   useEffect(() => {
-    if (!open) return;
+    if (!open || isAdminView) return;
     let active = true;
 
     const loadStatus = async () => {
@@ -156,7 +169,7 @@ const BookingDialog = ({
     return () => {
       active = false;
     };
-  }, [open, course.id]);
+  }, [open, course.id, isAdminView]);
 
   const handleBooking = async () => {
     setIsSubmitting(true);
@@ -193,6 +206,10 @@ const BookingDialog = ({
     }
   };
 
+  const adminStatus = isAdminView
+    ? (ADMIN_PAYMENT_LABELS[paymentStatus!] ?? ADMIN_PAYMENT_LABELS.pending)
+    : null;
+
   return (
     <Dialog open={open} onOpenChange={onOpenChange}>
       <DialogContent className="sm:max-w-3xl! w-[95vw] max-w-[calc(100%-1rem)] p-0 overflow-hidden gap-0 max-h-[90vh] sm:max-h-[85vh] flex flex-col">
@@ -315,33 +332,54 @@ const BookingDialog = ({
           </div>
         </div>
 
-        {/* Sticky Footer: bleibt immer sichtbar, auf Mobile gestapelt */}
+        {/* Sticky Footer */}
         <div className="shrink-0 border-t border-gray-200 bg-white px-4 sm:px-6 py-3 sm:py-4 flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
           <span className="text-lg font-bold text-gray-900">Preis: {formattedPrice}</span>
-          <div className="flex gap-2 w-full sm:w-auto">
-            <Button
-              variant="outline"
-              onClick={() => onOpenChange(false)}
-              className="flex-1 sm:flex-initial"
-            >
-              Schließen
-            </Button>
-            {isCheckingStatus ? (
-              <Button disabled className="flex-1 sm:flex-initial">
-                Lade…
-              </Button>
-            ) : isBooked ? (
-              <Button disabled className="flex-1 sm:flex-initial">
-                ✓ Angemeldet
-              </Button>
+          <div className="flex items-center gap-3 w-full sm:w-auto">
+            {/* Admin-Ansicht: nur Status-Badge + Schließen */}
+            {isAdminView ? (
+              <>
+                <span
+                  className={`text-sm font-semibold px-3 py-1.5 rounded-full ${adminStatus!.bg} ${adminStatus!.text}`}
+                >
+                  {adminStatus!.label}
+                </span>
+                <Button
+                  variant="outline"
+                  onClick={() => onOpenChange(false)}
+                  className="flex-1 sm:flex-initial"
+                >
+                  Schließen
+                </Button>
+              </>
             ) : (
-              <Button
-                onClick={handleBooking}
-                disabled={isSubmitting || isFull}
-                className="flex-1 sm:flex-initial"
-              >
-                {isSubmitting ? "Wird gebucht…" : isFull ? "Ausgebucht" : "Buchen"}
-              </Button>
+              /* Public-Ansicht: Buchen-Button */
+              <>
+                <Button
+                  variant="outline"
+                  onClick={() => onOpenChange(false)}
+                  className="flex-1 sm:flex-initial"
+                >
+                  Schließen
+                </Button>
+                {isCheckingStatus ? (
+                  <Button disabled className="flex-1 sm:flex-initial">
+                    Lade…
+                  </Button>
+                ) : isBooked ? (
+                  <Button disabled className="flex-1 sm:flex-initial">
+                    ✓ Angemeldet
+                  </Button>
+                ) : (
+                  <Button
+                    onClick={handleBooking}
+                    disabled={isSubmitting || isFull}
+                    className="flex-1 sm:flex-initial"
+                  >
+                    {isSubmitting ? "Wird gebucht…" : isFull ? "Ausgebucht" : "Buchen"}
+                  </Button>
+                )}
+              </>
             )}
           </div>
         </div>
diff --git a/src/modules/kunden/actions/kunde-detail-actions.ts b/src/modules/kunden/actions/kunde-detail-actions.ts
new file mode 100644
index 0000000..862a4cc
--- /dev/null
+++ b/src/modules/kunden/actions/kunde-detail-actions.ts
@@ -0,0 +1,196 @@
+"use server";
+
+import { prisma } from "@/src/lib/prisma";
+import { requireManager } from "@/src/lib/auth/getUser";
+import { unstable_cache } from "next/cache";
+
+export type KundeBooking = {
+  bookingId: string;
+  courseId: string;
+  courseName: string;
+  date: string; // ISO
+  timeFrom: string;
+  timeTo: string;
+  roomName: string;
+  // Felder für den PublicCourseCard-Dialog
+  level: string;
+  price: number;
+  maxParticipants: number;
+  currentParticipants: number;
+  coverImage: string | null;
+  description: string;
+  trainerProfiles: {
+    id: string;
+    firstName: string | null;
+    lastName: string | null;
+    pbSrc: string | null;
+  }[];
+  // Für die Card-Anzeige
+  trainers: string[];
+  trainersMap: Record<string, { label: string; pbSrc?: string }>;
+  paymentStatus: string;
+  isPast: boolean;
+};
+
+export type KundeDetail = {
+  id: string;
+  name: string;
+  email: string;
+  telefon: string;
+  gender: string | null;
+  birthday: Date | null;
+  pbSrc: string | null;
+  createdAt: Date | null;
+  bookings: KundeBooking[];
+};
+
+export async function getKundeDetail(
+  kundeId: string
+): Promise<{ success: true; kunde: KundeDetail } | { success: false; error: string }> {
+  const manager = await requireManager();
+  const businessIds = manager.businesses.map((b) => b.id);
+
+  const fetchDetail = unstable_cache(
+    async () => {
+      // Alles parallel: User+Bookings und Räume des Managers
+      const [userWithBookings, allRooms] = await Promise.all([
+        prisma.user.findUnique({
+          where: { id: kundeId },
+          select: {
+            id: true,
+            name: true,
+            email: true,
+            tel: true,
+            gender: true,
+            birthday: true,
+            pbSrc: true,
+            createdAt: true,
+            courseBookings: {
+              where: {
+                course: { businessId: { in: businessIds } },
+              },
+              select: {
+                id: true,
+                paymentStatus: true,
+                course: {
+                  select: {
+                    id: true,
+                    name: true,
+                    date: true,
+                    timeFrom: true,
+                    timeTo: true,
+                    room: true,
+                    trainers: true,
+                    // Dialog-Felder
+                    level: true,
+                    price: true,
+                    maxParticipants: true,
+                    coverImage: true,
+                    description: true,
+                    // Anzahl aller Buchungen für diesen Kurs
+                    _count: { select: { bookings: true } },
+                  },
+                },
+              },
+              orderBy: { createdAt: "desc" },
+            },
+          },
+        }),
+        prisma.room.findMany({
+          where: { createdBy: manager.id },
+          select: { id: true, name: true },
+        }),
+      ]);
+
+      if (!userWithBookings) return null;
+
+      // Raum-ID → Name
+      const roomsMap: Record<string, string> = {};
+      for (const r of allRooms) roomsMap[r.id] = r.name;
+
+      // Alle Trainer-IDs sammeln
+      const allTrainerIds = new Set<string>();
+      for (const b of userWithBookings.courseBookings) {
+        for (const tid of b.course.trainers) allTrainerIds.add(tid);
+      }
+
+      // Trainer-Daten laden (ein Query für alle)
+      const trainersData = await prisma.employee.findMany({
+        where: { id: { in: Array.from(allTrainerIds) } },
+        select: { id: true, firstName: true, lastName: true, pbSrc: true },
+      });
+
+      // trainersMap für die Card-Avatare (id → label+pbSrc)
+      const trainersMap: Record<string, { label: string; pbSrc?: string }> = {};
+      for (const t of trainersData) {
+        const label = [t.firstName, t.lastName].filter(Boolean).join(" ") || "Trainer";
+        trainersMap[t.id] = { label, pbSrc: t.pbSrc ?? undefined };
+      }
+
+      // trainerProfiles-Map für den Dialog (id → volles Profil)
+      const trainerProfilesMap: Record<
+        string,
+        { id: string; firstName: string | null; lastName: string | null; pbSrc: string | null }
+      > = {};
+      for (const t of trainersData) {
+        trainerProfilesMap[t.id] = {
+          id: t.id,
+          firstName: t.firstName,
+          lastName: t.lastName,
+          pbSrc: t.pbSrc,
+        };
+      }
+
+      const now = new Date();
+
+      const bookings: KundeBooking[] = userWithBookings.courseBookings.map((b) => {
+        const courseDate = new Date(b.course.date);
+        return {
+          bookingId: b.id,
+          courseId: b.course.id,
+          courseName: b.course.name,
+          date: b.course.date.toISOString(),
+          timeFrom: b.course.timeFrom,
+          timeTo: b.course.timeTo,
+          roomName: roomsMap[b.course.room] ?? b.course.room,
+          level: b.course.level,
+          price: b.course.price,
+          maxParticipants: b.course.maxParticipants,
+          currentParticipants: b.course._count.bookings,
+          coverImage: b.course.coverImage ?? null,
+          description: b.course.description,
+          trainerProfiles: b.course.trainers.map((tid) => trainerProfilesMap[tid]).filter(Boolean),
+          trainers: b.course.trainers,
+          trainersMap,
+          paymentStatus: b.paymentStatus,
+          isPast: courseDate < now,
+        };
+      });
+
+      return {
+        id: userWithBookings.id,
+        name: userWithBookings.name ?? userWithBookings.email,
+        email: userWithBookings.email,
+        telefon: userWithBookings.tel ?? "–",
+        gender: userWithBookings.gender,
+        birthday: userWithBookings.birthday,
+        pbSrc: userWithBookings.pbSrc,
+        createdAt: userWithBookings.createdAt,
+        bookings,
+      } satisfies KundeDetail;
+    },
+    [`kunde-detail-${kundeId}-${manager.id}`],
+    {
+      tags: [`kunde-detail-${kundeId}`, `manager-${manager.id}`],
+      revalidate: 60,
+    }
+  );
+
+  try {
+    const kunde = await fetchDetail();
+    if (!kunde) return { success: false, error: "Kunde nicht gefunden." };
+    return { success: true, kunde };
+  } catch {
+    return { success: false, error: "Kundendetails konnten nicht geladen werden." };
+  }
+}
diff --git a/src/modules/kunden/ui/components/kunde-booking-card.tsx b/src/modules/kunden/ui/components/kunde-booking-card.tsx
new file mode 100644
index 0000000..eb7d8d4
--- /dev/null
+++ b/src/modules/kunden/ui/components/kunde-booking-card.tsx
@@ -0,0 +1,129 @@
+"use client";
+
+import { useState } from "react";
+import Image from "next/image";
+import { MapPin, Clock } from "lucide-react";
+import type { KundeBooking } from "../../actions/kunde-detail-actions";
+import AbstractTooltip from "@/src/components/layout/AbstractTooltip";
+import { BookingDialog } from "@/src/modules/courses/ui/components/PublicCourseCard";
+import type { PublicCourse } from "@/src/modules/courses/ui/components/PublicCourseCard";
+
+const getDiceBearUrl = (seed: string) =>
+  `https://api.dicebear.com/9.x/thumbs/svg?seed=${encodeURIComponent(seed)}`;
+
+const PAYMENT_STATUS: Record<string, { label: string; bg: string; text: string }> = {
+  paid: { label: "Bezahlt", bg: "bg-green-100", text: "text-green-700" },
+  pending: { label: "Ausstehend", bg: "bg-yellow-100", text: "text-yellow-700" },
+  refunded: { label: "Storniert", bg: "bg-red-100", text: "text-red-600" },
+  failed: { label: "Fehlgeschlagen", bg: "bg-red-100", text: "text-red-600" },
+};
+
+/** KundeBooking → PublicCourse für den BookingDialog */
+function toPublicCourse(b: KundeBooking): PublicCourse {
+  return {
+    id: b.courseId,
+    name: b.courseName,
+    sport: [],
+    level: b.level,
+    date: new Date(b.date),
+    timeFrom: b.timeFrom,
+    timeTo: b.timeTo,
+    maxParticipants: b.maxParticipants,
+    price: b.price,
+    currentParticipants: b.currentParticipants,
+    description: b.description,
+    roomName: b.roomName,
+    coverImage: b.coverImage ?? undefined,
+    trainerProfiles: b.trainerProfiles,
+  };
+}
+
+interface KundeBookingCardProps {
+  booking: KundeBooking;
+}
+
+const KundeBookingCard = ({ booking }: KundeBookingCardProps) => {
+  const [dialogOpen, setDialogOpen] = useState(false);
+  const status = PAYMENT_STATUS[booking.paymentStatus] ?? PAYMENT_STATUS.pending;
+
+  const dateFormatted = new Date(booking.date).toLocaleDateString("de-DE", {
+    day: "2-digit",
+    month: "2-digit",
+    year: "numeric",
+  });
+
+  return (
+    <>
+      <div
+        onClick={() => setDialogOpen(true)}
+        className="bg-white/70 backdrop-blur-sm border border-white/50 rounded-xl p-4 shadow-sm hover:shadow-md hover:bg-white/85 transition-all cursor-pointer flex flex-col gap-3 select-none"
+      >
+        {/* Trainer Avatare + Uhrzeit */}
+        <div className="flex items-center justify-between">
+          <div className="flex items-center">
+            {booking.trainers.length > 0 ? (
+              booking.trainers.map((tid, idx) => {
+                const info = booking.trainersMap[tid];
+                const name = info?.label ?? "Trainer";
+                const src = info?.pbSrc ?? getDiceBearUrl(tid);
+                return (
+                  <AbstractTooltip key={tid} tooltipText={name}>
+                    <div
+                      className={`relative w-8 h-8 rounded-full border-2 border-white overflow-hidden bg-gray-100 ${
+                        idx !== 0 ? "-ml-2" : ""
+                      }`}
+                      style={{ zIndex: booking.trainers.length - idx }}
+                    >
+                      <Image src={src} alt={name} fill className="object-cover" unoptimized />
+                    </div>
+                  </AbstractTooltip>
+                );
+              })
+            ) : (
+              <div className="w-8 h-8 rounded-full bg-gray-200 flex items-center justify-center text-xs text-gray-400">
+                –
+              </div>
+            )}
+          </div>
+          <span className="text-sm text-gray-500 flex items-center gap-1">
+            <Clock size={13} className="shrink-0" />
+            {booking.timeFrom} – {booking.timeTo}
+          </span>
+        </div>
+
+        {/* Kursname */}
+        <h3 className="font-semibold text-gray-900 text-base leading-tight">
+          {booking.courseName}
+        </h3>
+
+        {/* Datum + Raum */}
+        <div className="flex items-center justify-between text-sm text-gray-500">
+          <span>{dateFormatted}</span>
+          <span className="flex items-center gap-1">
+            <MapPin size={13} className="shrink-0" />
+            {booking.roomName}
+          </span>
+        </div>
+
+        {/* Status Badge */}
+        <div>
+          <span
+            className={`inline-block text-xs font-semibold px-2.5 py-1 rounded-full ${status.bg} ${status.text}`}
+          >
+            {status.label}
+          </span>
+        </div>
+      </div>
+
+      {/* Exakt derselbe Dialog wie auf der Public Page, aber in der Admin-Ansicht */}
+      <BookingDialog
+        course={toPublicCourse(booking)}
+        open={dialogOpen}
+        onOpenChange={setDialogOpen}
+        paymentStatus={booking.paymentStatus}
+      />
+    </>
+  );
+};
+
+export default KundeBookingCard;
diff --git a/src/modules/kunden/ui/views/kunde-detail-view.tsx b/src/modules/kunden/ui/views/kunde-detail-view.tsx
new file mode 100644
index 0000000..a9bcd6d
--- /dev/null
+++ b/src/modules/kunden/ui/views/kunde-detail-view.tsx
@@ -0,0 +1,305 @@
+"use client";
+
+import { useState } from "react";
+import Image from "next/image";
+import {
+  Phone,
+  Mail,
+  User,
+  Calendar,
+  Hash,
+  ChevronDown,
+  ChevronUp,
+  BookOpen,
+  History,
+  CreditCard,
+  Bell,
+  Scale,
+  CheckCircle2,
+} from "lucide-react";
+import type { KundeDetail } from "../../actions/kunde-detail-actions";
+import KundeBookingCard from "../components/kunde-booking-card";
+
+// ─── DiceBear Fallback ────────────────────────────────────────────────────────
+const getDiceBearUrl = (seed: string) =>
+  `https://api.dicebear.com/9.x/thumbs/svg?seed=${encodeURIComponent(seed)}`;
+
+// ─── ID kürzen: erste 8 Zeichen + … ──────────────────────────────────────────
+const shortenId = (id: string) => `${id.slice(0, 8)}…${id.slice(-4)}`;
+
+// ─── Kollapsible Sektion ──────────────────────────────────────────────────────
+interface CollapsibleSectionProps {
+  icon: React.ReactNode;
+  title: string;
+  defaultOpen?: boolean;
+  children: React.ReactNode;
+  badge?: number | string;
+}
+
+const CollapsibleSection = ({
+  icon,
+  title,
+  defaultOpen = true,
+  children,
+  badge,
+}: CollapsibleSectionProps) => {
+  const [open, setOpen] = useState(defaultOpen);
+
+  return (
+    <div className="rounded-2xl border border-white/60 bg-white/55 backdrop-blur-xl shadow-sm overflow-hidden">
+      <button
+        onClick={() => setOpen((v) => !v)}
+        className="w-full flex items-center justify-between px-5 py-4 hover:bg-white/50 transition-colors"
+      >
+        <div className="flex items-center gap-3">
+          <span className="text-blue">{icon}</span>
+          <span className="font-semibold text-gray-800 text-base">{title}</span>
+          {badge !== undefined && (
+            <span className="text-xs font-semibold px-2 py-0.5 rounded-full bg-blue/10 text-blue">
+              {badge}
+            </span>
+          )}
+        </div>
+        {open ? (
+          <ChevronUp size={18} className="text-gray-400" />
+        ) : (
+          <ChevronDown size={18} className="text-gray-400" />
+        )}
+      </button>
+      {open && <div className="px-5 pb-5 pt-1 border-t border-white/40">{children}</div>}
+    </div>
+  );
+};
+
+// ─── Info-Zeile in der ID-Karte ───────────────────────────────────────────────
+interface InfoRowProps {
+  icon: React.ReactNode;
+  label: string;
+  value: React.ReactNode;
+}
+
+const InfoRow = ({ icon, label, value }: InfoRowProps) => (
+  <div className="flex items-start gap-2.5">
+    <span className="mt-0.5 text-blue shrink-0">{icon}</span>
+    <div className="min-w-0">
+      <p className="text-xs text-gray-400 leading-none mb-0.5">{label}</p>
+      <p className="font-medium text-gray-800 text-sm truncate">{value}</p>
+    </div>
+  </div>
+);
+
+// ─── Haupt-View ───────────────────────────────────────────────────────────────
+interface KundeDetailViewProps {
+  kunde: KundeDetail;
+}
+
+const KundeDetailView = ({ kunde }: KundeDetailViewProps) => {
+  const avatarSrc = kunde.pbSrc ?? getDiceBearUrl(kunde.id);
+
+  const upcomingBookings = kunde.bookings.filter((b) => !b.isPast);
+  const pastBookings = kunde.bookings.filter((b) => b.isPast);
+
+  const genderLabel: Record<string, string> = {
+    male: "Männlich",
+    female: "Weiblich",
+    diverse: "Divers",
+  };
+
+  const birthdayFormatted = kunde.birthday
+    ? new Date(kunde.birthday).toLocaleDateString("de-DE", {
+        day: "2-digit",
+        month: "2-digit",
+        year: "numeric",
+      })
+    : "–";
+
+  const memberSinceFormatted = kunde.createdAt
+    ? new Date(kunde.createdAt).toLocaleDateString("de-DE", {
+        day: "2-digit",
+        month: "long",
+        year: "numeric",
+      })
+    : "–";
+
+  return (
+    <div className="flex flex-col gap-5 w-full">
+      {/* Kundenname */}
+      <h1 className="text-4xl font-bold">{kunde.name}</h1>
+
+      {/* ── Glassmorphism ID-Karte ── */}
+      <div className="relative rounded-2xl overflow-hidden border border-white/60 shadow-lg w-full">
+        {/* weißes Glas-Hintergrundpanel */}
+        <div className="absolute inset-0 bg-white/40 backdrop-blur-2xl" />
+        {/* subtiler weißer Glanz-Schein oben */}
+        <div className="absolute inset-x-0 top-0 h-px bg-white/80" />
+
+        <div className="relative p-6 flex flex-col sm:flex-row items-start gap-6">
+          {/* Avatar – größer */}
+          <div className="relative w-28 h-28 rounded-full overflow-hidden border-4 border-white/80 shadow-lg shrink-0 bg-white/50">
+            <Image src={avatarSrc} alt={kunde.name} fill className="object-cover" unoptimized />
+          </div>
+
+          {/* Info-Grid */}
+          <div className="flex-1 grid grid-cols-1 sm:grid-cols-2 gap-x-10 gap-y-4">
+            <InfoRow icon={<Phone size={15} />} label="Telefon" value={kunde.telefon} />
+            <InfoRow icon={<Mail size={15} />} label="E-Mail" value={kunde.email} />
+            <InfoRow
+              icon={<User size={15} />}
+              label="Geschlecht"
+              value={kunde.gender ? (genderLabel[kunde.gender] ?? kunde.gender) : "–"}
+            />
+            <InfoRow icon={<Calendar size={15} />} label="Geburtsdatum" value={birthdayFormatted} />
+            {/* Kunden-ID über volle Breite */}
+            <div className="sm:col-span-2 flex items-start gap-2.5">
+              <span className="mt-0.5 text-blue shrink-0">
+                <Hash size={15} />
+              </span>
+              <div className="min-w-0">
+                <p className="text-xs text-gray-400 leading-none mb-0.5">Kunden-ID</p>
+                <p
+                  className="font-mono text-sm text-gray-700 truncate cursor-default"
+                  title={kunde.id}
+                >
+                  {shortenId(kunde.id)}
+                </p>
+              </div>
+            </div>
+          </div>
+
+          {/* Mitglied-seit Chip – oben rechts auf Desktop */}
+          <div className="sm:absolute sm:top-4 sm:right-5 shrink-0">
+            <span className="text-xs text-gray-500 bg-white/70 border border-white/60 px-3 py-1 rounded-full shadow-sm whitespace-nowrap">
+              Mitglied seit {memberSinceFormatted}
+            </span>
+          </div>
+        </div>
+      </div>
+
+      {/* ── Gebuchte Kurse (zukünftig) ── */}
+      <CollapsibleSection
+        icon={<BookOpen size={18} />}
+        title="Gebuchte Kurse"
+        badge={upcomingBookings.length}
+        defaultOpen={true}
+      >
+        {upcomingBookings.length === 0 ? (
+          <p className="text-sm text-muted-foreground py-3">Keine bevorstehenden Kursbuchungen.</p>
+        ) : (
+          <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-3 pt-3">
+            {upcomingBookings.map((b) => (
+              <KundeBookingCard key={b.bookingId} booking={b} />
+            ))}
+          </div>
+        )}
+      </CollapsibleSection>
+
+      {/* ── Vergangene Kurse ── */}
+      <CollapsibleSection
+        icon={<History size={18} />}
+        title="Vergangene Kurse"
+        badge={pastBookings.length}
+        defaultOpen={false}
+      >
+        {pastBookings.length === 0 ? (
+          <p className="text-sm text-muted-foreground py-3">Keine vergangenen Kursbuchungen.</p>
+        ) : (
+          <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 xl:grid-cols-4 gap-3 pt-3">
+            {pastBookings.map((b) => (
+              <KundeBookingCard key={b.bookingId} booking={b} />
+            ))}
+          </div>
+        )}
+      </CollapsibleSection>
+
+      {/* ── Abonnements & Credits (Dummy) ── */}
+      <CollapsibleSection
+        icon={<CreditCard size={18} />}
+        title="Abonnements & Credits"
+        defaultOpen={false}
+      >
+        <div className="pt-3 flex flex-col gap-2.5">
+          {[
+            { label: "Aktive Abonnements", value: "1 Abo" },
+            { label: "Übrige Buchungen", value: "4" },
+            { label: "Credits", value: "0" },
+          ].map((row) => (
+            <div
+              key={row.label}
+              className="flex items-center justify-between rounded-xl bg-white/60 border border-white/50 px-4 py-3"
+            >
+              <span className="text-sm text-gray-600">{row.label}</span>
+              <span className="font-semibold text-gray-900 text-sm">{row.value}</span>
+            </div>
+          ))}
+        </div>
+      </CollapsibleSection>
+
+      {/* ── Benachrichtigungen (Dummy) ── */}
+      <CollapsibleSection icon={<Bell size={18} />} title="Benachrichtigungen" defaultOpen={false}>
+        <div className="pt-3 grid grid-cols-1 sm:grid-cols-2 gap-2.5">
+          {[
+            { label: "Newsletter", value: "Nein" },
+            { label: "Marketing", value: "Nein" },
+            { label: "Buchungsbestätigung", value: "Ja" },
+            { label: "Warteliste", value: "Ja" },
+            { label: "Erinnerungen", value: "Ja" },
+            { label: "Kursbeginn", value: "Ja" },
+            { label: "Kursänderungen", value: "Ja" },
+            { label: "Abonnements-News", value: "Nein" },
+          ].map((item) => (
+            <div
+              key={item.label}
+              className="flex items-center justify-between rounded-xl bg-white/60 border border-white/50 px-4 py-3"
+            >
+              <span className="text-sm text-gray-600">{item.label}</span>
+              <span
+                className={`text-sm font-semibold ${
+                  item.value === "Ja" ? "text-green-600" : "text-red-500"
+                }`}
+              >
+                {item.value}
+              </span>
+            </div>
+          ))}
+        </div>
+      </CollapsibleSection>
+
+      {/* ── Rechtliches (Dummy) ── */}
+      <CollapsibleSection icon={<Scale size={18} />} title="Rechtliches" defaultOpen={false}>
+        <div className="pt-3 grid grid-cols-1 sm:grid-cols-2 gap-2.5">
+          {/* AGB */}
+          <div className="rounded-xl bg-white/60 border border-white/50 px-4 py-4">
+            <div className="flex items-start gap-3">
+              <CheckCircle2 size={18} className="text-green-500 mt-0.5 shrink-0" />
+              <div>
+                <p className="font-semibold text-gray-800 text-sm">AGB</p>
+                <p className="text-xs text-gray-500 mt-0.5">Zustimmung: Ja</p>
+                <p className="text-xs text-gray-400 mt-0.5">Datum: 14.01.2025</p>
+                <p className="text-xs text-gray-400">Uhrzeit: 19:51</p>
+                <p className="text-xs text-gray-400 font-mono mt-1">Version 1.0.0</p>
+              </div>
+            </div>
+          </div>
+
+          {/* Datenschutzerklärung */}
+          <div className="rounded-xl bg-white/60 border border-white/50 px-4 py-4">
+            <div className="flex items-start gap-3">
+              <CheckCircle2 size={18} className="text-green-500 mt-0.5 shrink-0" />
+              <div>
+                <p className="font-semibold text-gray-800 text-sm">Datenschutzerklärung</p>
+                <p className="text-xs text-gray-500 mt-0.5">Zustimmung: Ja</p>
+                <p className="text-xs text-gray-400 mt-0.5">Datum: 14.01.2025</p>
+                <p className="text-xs text-gray-400">Uhrzeit: 19:51</p>
+                <button className="text-xs text-blue underline mt-2 hover:opacity-70 transition-opacity">
+                  Datenschutzerklärung ansehen
+                </button>
+              </div>
+            </div>
+          </div>
+        </div>
+      </CollapsibleSection>
+    </div>
+  );
+};
+
+export default KundeDetailView;