feat: add gentle loading fallback after 3 seconds

If no lesson loads within 3 seconds, show a centered, gray notice
with fade-in animation suggesting to select from menu or check help.
Includes link to help dialog.

src/app.js

@@ -238,6 +238,29 @@ function restoreLessonCache() {
 
 // ================= MODULE INITIALIZATION =================
 
+let loadingTimeout = null;
+
+function showLoadingFallback() {
+	// Only show if no lesson is loaded yet
+	if (!elements.lessonTitle.textContent) {
+		elements.lessonDescription.innerHTML = `
+			<div class="loading-fallback">
+				<p>${t("loadingFallbackText")}</p>
+				<button class="btn btn-text" onclick="document.getElementById('help-btn').click()">
+					${t("help")}
+				</button>
+			</div>
+		`;
+	}
+}
+
+function clearLoadingTimeout() {
+	if (loadingTimeout) {
+		clearTimeout(loadingTimeout);
+		loadingTimeout = null;
+	}
+}
+
 async function initializeModules() {
 	try {
 		const modules = await loadModules(getLanguage());
@@ -257,9 +280,10 @@ async function initializeModules() {
 		}
 
 		updateProgressDisplay();
+		clearLoadingTimeout();
 	} catch (error) {
 		console.error("Failed to load modules:", error);
-		elements.lessonDescription.textContent = t("failedToLoad");
+		showLoadingFallback();
 	}
 }
 
@@ -656,6 +680,9 @@ function init() {
 	// Initialize CodeMirror editor
 	initCodeEditor();
 
+	// Set timeout to show fallback if loading takes too long
+	loadingTimeout = setTimeout(showLoadingFallback, 3000);
+
 	// Load modules after editor is ready
 	initializeModules().catch(console.error);
 

src/i18n.js

@@ -87,6 +87,7 @@ const translations = {
 		resetAll: "Reset All",
 
 		// Dynamic content
+		loadingFallbackText: "Could not load lesson. Please select one from the menu or check the help.",
 		completed: "Completed",
 		successMessage: "CRISPY! ٩(◕‿◕)۶ Your code works correctly.",
 		keepTrying: "Keep trying!",
@@ -180,6 +181,7 @@ const translations = {
 		resetAll: "Alles zurücksetzen",
 
 		// Dynamic content
+		loadingFallbackText: "Lektion konnte nicht geladen werden. Bitte wähle eine aus dem Menü oder prüfe die Hilfe.",
 		completed: "Erledigt",
 		successMessage: "CRISPY! ٩(◕‿◕)۶ Dein Code funktioniert.",
 		keepTrying: "Weiter versuchen!",

src/main.css

@@ -241,6 +241,23 @@ code, kbd {
 	opacity: 0.3;
 }
 
+/* Loading fallback notice */
+.loading-fallback {
+	text-align: center;
+	padding: 3rem 1rem;
+	color: var(--light-text);
+	animation: fadeIn 0.5s ease;
+}
+
+.loading-fallback p {
+	margin-bottom: 1rem;
+}
+
+@keyframes fadeIn {
+	from { opacity: 0; }
+	to { opacity: 1; }
+}
+
 .module-pill {
 	display: inline-flex;
 	align-items: center;