Fix responsive layout on artwork single page

src/components/artworks/ContextBackButton.tsx

@@ -10,7 +10,7 @@ const FROM_TO_PATH: Record<string, string> = {
   "animal-index": "/artworks/animalstudies/index"
 };
 
-export function ContextBackButton() {
+export function ContextBackButton({ className }: { className?: string }) {
   const router = useRouter();
   const sp = useSearchParams();
   const from = sp.get("from") ?? "";
@@ -19,7 +19,7 @@ export function ContextBackButton() {
   if (!target) return null;
 
   return (
-    <div className="w-full max-w-xl">
+    <div className={["w-full max-w-xl", className].filter(Boolean).join(" ")}>
       <Link
         href={target}
         className={[