feat: add lightbox for viewing forest and reward images fullscreen

- Click any forest element or reward image to see it large
- Smooth zoom-in animation, click anywhere to close
- Hover effect on clickable images
- Works on both forest grid and reward screen

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

index.html

@@ -195,6 +195,11 @@
 			<span class="mute-btn__icon" id="mute-icon">&#x1F50A;</span>
 		</button>
 
+		<!-- Lightbox for forest element images -->
+		<div id="image-lightbox" class="lightbox" style="display:none">
+			<img id="lightbox-img" class="lightbox__img" src="" alt="">
+		</div>
+
 		<script type="module" src="/src/main.ts"></script>
 	</body>
 </html>

src/main.ts

@@ -64,4 +64,27 @@ document.addEventListener("DOMContentLoaded", async () => {
 	};
 	document.addEventListener("click", initAudioOnce);
 	document.addEventListener("keydown", initAudioOnce);
+
+	// Lightbox: click on forest/reward images to view fullscreen
+	const lightbox = document.getElementById("image-lightbox")!;
+	const lightboxImg = document.getElementById("lightbox-img") as HTMLImageElement;
+
+	document.addEventListener("click", (e) => {
+		const target = e.target as HTMLElement;
+		// Open lightbox when clicking forest element or reward image
+		if (
+			(target.tagName === "IMG" && target.closest(".forest__element")) ||
+			(target.tagName === "IMG" && target.closest(".reward__image-area"))
+		) {
+			lightboxImg.src = (target as HTMLImageElement).src;
+			lightboxImg.alt = (target as HTMLImageElement).alt;
+			lightbox.style.display = "flex";
+		}
+	});
+
+	// Close lightbox on click
+	lightbox.addEventListener("click", () => {
+		lightbox.style.display = "none";
+		lightboxImg.src = "";
+	});
 });

src/styles/main.css

@@ -484,9 +484,15 @@ h3 {
 	max-height: 100%;
 	object-fit: cover;
 	border-radius: 50%;
+	cursor: pointer;
 	filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.15));
 	mask-image: radial-gradient(ellipse 70% 70% at center, black 50%, transparent 100%);
 	-webkit-mask-image: radial-gradient(ellipse 70% 70% at center, black 50%, transparent 100%);
+	transition: transform 0.2s ease;
+}
+
+.forest__element img:hover {
+	transform: scale(1.1);
 }
 
 .forest__element--new {
@@ -542,7 +548,13 @@ h3 {
 	max-width: 100%;
 	max-height: 100%;
 	object-fit: contain;
+	cursor: pointer;
 	animation: reward-image-appear 0.8s ease-out;
+	transition: transform 0.2s ease;
+}
+
+.reward__image-area img:hover {
+	transform: scale(1.05);
 }
 
 @keyframes reward-image-appear {
@@ -995,6 +1007,38 @@ h3 {
 	opacity: 0.6;
 }
 
+/* Lightbox for viewing forest images fullscreen */
+.lightbox {
+	position: fixed;
+	inset: 0;
+	background: rgba(61, 50, 37, 0.85);
+	z-index: 500;
+	display: flex;
+	align-items: center;
+	justify-content: center;
+	cursor: pointer;
+	animation: lightbox-fade-in 0.3s ease;
+}
+
+.lightbox__img {
+	max-width: 90vw;
+	max-height: 85vh;
+	object-fit: contain;
+	border-radius: 16px;
+	box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
+	animation: lightbox-zoom-in 0.3s ease;
+}
+
+@keyframes lightbox-fade-in {
+	from { opacity: 0; }
+	to { opacity: 1; }
+}
+
+@keyframes lightbox-zoom-in {
+	from { transform: scale(0.7); opacity: 0; }
+	to { transform: scale(1); opacity: 1; }
+}
+
 /* Error overlay — kindgerechte Fehlermeldung */
 .error-overlay {
 	position: fixed;