working on course details again

Signed-off-by: Kenneth Obsequio <k80308392@gmail.com>

src/modules/client/pages/UnitList.jsx

@@ -1,7 +1,7 @@
 import { useState, useCallback, useEffect, useRef } from "react";
 import AppBreadcrumb from "@/components/generic/Breadcrumb/AppBreadcrumb";
 import { useParams, useNavigate, useLocation, useBlocker } from "react-router-dom";
-import { House, TableOfContents, ArrowRight, ClipboardList, GraduationCap, Trophy, Lock, CheckCircle2, Circle, Zap, ListChecks, ChevronsLeft, ChevronsRight } from "lucide-react";
+import { House, TableOfContents, ArrowRight, ClipboardList, GraduationCap, Trophy, Lock, CheckCircle2, Circle, Zap, ListChecks, ChevronsLeft, ChevronsRight, Hourglass } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import {
     Accordion,
@@ -726,6 +726,26 @@ const UnitList = () => {
         );
     }
 
+    // ── Content not ready (duration_seconds === 0 — no lesson content authored yet) ──
+    if (!courseLoading && course && !course.duration_seconds) {
+        return (
+            <div className="flex flex-col items-center gap-6 py-32 text-center px-4">
+                <div className="h-16 w-16 rounded-full bg-muted flex items-center justify-center">
+                    <Hourglass className="size-7 text-muted-foreground" />
+                </div>
+                <div className="space-y-2 max-w-sm">
+                    <h2 className="text-xl font-semibold">Course Not Yet Available</h2>
+                    <p className="text-sm text-muted-foreground leading-relaxed">
+                        This course is currently being prepared. Please check back later.
+                    </p>
+                </div>
+                <Button variant="outline" onClick={() => navigate(`/course/${courseId}`)} className="gap-1.5">
+                    Back to Course Details
+                </Button>
+            </div>
+        );
+    }
+
     return (
         <>
             <PageMeta title={pageTitle} />