see comments and fix individual course copy

src/app/courses/book/[courseId]/page.tsx

@@ -20,5 +20,5 @@ export default async function CourseBookingPage({ params }: CourseBookingPagePro
     notFound();
   }
 
-  redirect(`/business/${result.course.business.slug}`);
+  redirect(`/business/${result.course.business.slug}?course=${courseId}`);
 }

src/modules/courses/actions/booking-actions.ts

@@ -59,8 +59,11 @@ export async function checkUserBookingStatus(courseId: string) {
  */
 export async function getCourseSummaryForConfirmation(courseId: string) {
   try {
-    const course = await prisma.course.findUnique({
-      where: { id: courseId },
+    const course = await prisma.course.findFirst({
+      where: {
+        id: courseId,
+        business: { isPublic: true },
+      },
       select: {
         id: true,
         name: true,

src/modules/courses/ui/components/PublicCourseCard.tsx

@@ -52,6 +52,7 @@ interface PublicCourse {
 interface PublicCourseCardProps {
   course: PublicCourse;
   business?: BusinessInfo;
+  defaultOpen?: boolean; // öffnet das Detail-Popup beim Mount (für Deep-Links)
 }
 
 const TrainerAvatar = ({ trainer, size }: { trainer: TrainerProfile; size: "sm" | "lg" }) => {
@@ -310,8 +311,8 @@ const BookingDialog = ({
   );
 };
 
-const PublicCourseCard = ({ course, business }: PublicCourseCardProps) => {
-  const [dialogOpen, setDialogOpen] = useState(false);
+const PublicCourseCard = ({ course, business, defaultOpen = false }: PublicCourseCardProps) => {
+  const [dialogOpen, setDialogOpen] = useState(defaultOpen);
 
   const cardSafeCurrent = Math.max(0, course.currentParticipants);
   const cardSafeMax = Math.max(0, course.maxParticipants);

src/modules/courses/ui/views/business-public-view.tsx

@@ -1,6 +1,7 @@
 "use client";
 
-import { useState, useTransition, useMemo } from "react";
+import { useState, useTransition, useMemo, useEffect } from "react";
+import { useSearchParams } from "next/navigation";
 import PublicCourseCard from "../components/PublicCourseCard";
 import { getPublishedCoursesForBusiness } from "../../actions/booking-actions";
 import { Calendar } from "@/src/components/ui/calendar";
@@ -58,6 +59,21 @@ const BusinessPublicView = ({
   const [activeSport, setActiveSport] = useState<string>("Alle");
   const [isPending, startTransition] = useTransition();
 
+  // Deep-Link: ?course=<id> öffnet das Detail-Popup des Kurses und springt
+  // auf dessen Datum, damit die Karte sichtbar ist (z.B. geteilter Buchungslink).
+  const searchParams = useSearchParams();
+  const deepLinkCourseId = searchParams.get("course");
+
+  useEffect(() => {
+    if (!deepLinkCourseId) return;
+    const target = loadedCourses.find((c) => c.id === deepLinkCourseId);
+    if (!target) return;
+    const day = new Date(target.date);
+    day.setHours(0, 0, 0, 0);
+    setSelectedDate(day);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [deepLinkCourseId]);
+
   const handleDateSelect = (date: Date | undefined) => {
     if (!date) return;
 
@@ -204,6 +220,7 @@ const BusinessPublicView = ({
                     key={course.id}
                     course={course}
                     business={{ address: business.address, email: business.email }}
+                    defaultOpen={course.id === deepLinkCourseId}
                   />
                 ))}
               </div>