fix(studio): widen chapter preview on large screens

packages/studio/src/App.tsx

@@ -274,7 +274,7 @@ export function App() {
             </div>
           )}
           {route.page === "chapter" && (
-            <div className="max-w-4xl mx-auto px-6 py-12 md:px-12 lg:py-16 fade-in">
+            <div className="mx-auto w-full max-w-[1400px] px-4 py-12 sm:px-6 lg:px-10 lg:py-16 2xl:px-12 fade-in">
               <ChapterReader bookId={route.bookId} chapterNumber={route.chapterNumber} nav={nav} theme={theme} t={t} />
             </div>
           )}

packages/studio/src/pages/ChapterReader.tsx

@@ -115,7 +115,7 @@ export function ChapterReader({ bookId, chapterNumber, nav, theme, t }: {
   const paragraphs = body.split(/\n\n+/).filter(Boolean);
 
   return (
-    <div className="max-w-4xl mx-auto space-y-10 fade-in">
+    <div className="w-full space-y-10 fade-in">
       {/* Navigation & Actions */}
       <div className="flex flex-col md:flex-row md:items-center justify-between gap-6">
         <nav className="flex items-center gap-2 text-[13px] font-medium text-muted-foreground">