diff --git a/apps/web/src/components/ObjectTree.tsx b/apps/web/src/components/ObjectTree.tsx
index dcac417..daa8e6f 100644
--- a/apps/web/src/components/ObjectTree.tsx
+++ b/apps/web/src/components/ObjectTree.tsx
@@ -5,11 +5,11 @@ import { iconsForObject } from './objectIcons';
 
 interface Props {
   nodes: ObjectTreeNode[];
-  selectedGuid: string | null;
-  onSelect: (guid: string) => void;
+  selectedPath: string | null;
+  onSelect: (path: string) => void;
 }
 
-export default function ObjectTree({ nodes, selectedGuid, onSelect }: Props) {
+export default function ObjectTree({ nodes, selectedPath, onSelect }: Props) {
   return (
     <ul className="space-y-0.5">
       {nodes.map((node, index) => (
@@ -18,7 +18,7 @@ export default function ObjectTree({ nodes, selectedGuid, onSelect }: Props) {
           node={node}
           depth={0}
           path={`${index}`}
-          selectedGuid={selectedGuid}
+          selectedPath={selectedPath}
           onSelect={onSelect}
         />
       ))}
@@ -30,17 +30,20 @@ function TreeNode({
   node,
   depth,
   path,
-  selectedGuid,
+  selectedPath,
   onSelect,
 }: {
   node: ObjectTreeNode;
   depth: number;
-  /** Index path from the root, used as a stable unique key. */
+  /** Index path from the root, used as a stable unique key and selection id. */
   path: string;
-  selectedGuid: string | null;
-  onSelect: (guid: string) => void;
+  selectedPath: string | null;
+  onSelect: (path: string) => void;
 }) {
-  const selected = node.object.GUID === selectedGuid;
+  // Selection is keyed by the node's unique index path, not its GUID: cards in
+  // a deck frequently share a GUID (the deck's), so GUID-based selection would
+  // highlight and render the wrong card.
+  const selected = path === selectedPath;
   const hasChildren = node.children.length > 0;
   const [expanded, setExpanded] = useState(false);
   return (
@@ -69,7 +72,7 @@ function TreeNode({
           <span className="h-6 w-6 shrink-0" />
         )}
         <button
-          onClick={() => onSelect(node.object.GUID)}
+          onClick={() => onSelect(path)}
           className="block min-w-0 flex-1 truncate py-1 text-left text-sm"
         >
           <span
@@ -91,7 +94,7 @@ function TreeNode({
               node={child}
               depth={depth + 1}
               path={`${path}-${index}`}
-              selectedGuid={selectedGuid}
+              selectedPath={selectedPath}
               onSelect={onSelect}
             />
           ))}
diff --git a/apps/web/src/pages/ModPage.tsx b/apps/web/src/pages/ModPage.tsx
index 3f0caf6..9024d1a 100644
--- a/apps/web/src/pages/ModPage.tsx
+++ b/apps/web/src/pages/ModPage.tsx
@@ -16,7 +16,10 @@ export default function ModPage() {
   const { id } = useParams<{ id: string }>();
   const { mod, loading, error, load } = useModStore();
   const item = useSearchStore((s) => s.items.find((i) => i.id === id));
-  const [selectedGuid, setSelectedGuid] = useState<string | null>(null);
+  // Selection is keyed by the node's index path, not its GUID: cards in a
+  // deck share the deck's GUID, so GUID-based selection would resolve to the
+  // wrong card.
+  const [selectedPath, setSelectedPath] = useState<string | null>(null);
 
   useEffect(() => {
     if (id) load(id, item?.fileUrl);
@@ -26,8 +29,8 @@ export default function ModPage() {
   const refs = useMemo(() => (mod ? collectRefs(mod) : []), [mod]);
 
   const selected = useMemo(
-    () => (mod ? findInTree(tree, selectedGuid) : undefined),
-    [tree, selectedGuid],
+    () => (mod ? findInTree(tree, selectedPath) : undefined),
+    [tree, selectedPath],
   );
 
   if (loading) return <p className="text-sm text-zinc-400">Loading mod…</p>;
@@ -56,8 +59,8 @@ export default function ModPage() {
         <aside className="rounded-lg border border-zinc-800 bg-zinc-900 p-2">
           <ObjectTree
             nodes={tree}
-            selectedGuid={selectedGuid}
-            onSelect={setSelectedGuid}
+            selectedPath={selectedPath}
+            onSelect={setSelectedPath}
           />
         </aside>
 
@@ -105,13 +108,11 @@ export default function ModPage() {
 
 function findInTree(
   nodes: ReturnType<typeof buildTree>,
-  guid: string | null,
+  path: string | null,
 ): ReturnType<typeof buildTree>[number] | undefined {
-  if (!guid) return undefined;
-  for (const node of nodes) {
-    if (node.object.GUID === guid) return node;
-    const found = findInTree(node.children, guid);
-    if (found) return found;
-  }
-  return undefined;
+  if (!path) return undefined;
+  const [head, ...rest] = path.split('-');
+  const node = nodes[Number(head)];
+  if (!node) return undefined;
+  return rest.length === 0 ? node : findInTree(node.children, rest.join('-'));
 }
\ No newline at end of file