feat(ui): warm library palette (zinc+emerald -> stone+amber) with hover/focus feedback; text reader gains paper/sepia/night themes + persisted font-size (lib/readerPrefs.ts), serif justified measure; PDF drops emoji icons for 首页/末页, CBZ pill page counter, EPUB centered spread, blur reader header with format badge, aria labels on login/search/chapter select

frontend/src/components/ErrorBoundary.tsx

@@ -13,8 +13,8 @@ export class ErrorBoundary extends Component<{ children: ReactNode }, { err: Err
         <div className="grid h-full place-items-center p-8 text-center">
           <div>
             <p className="mb-2 text-lg text-red-400">页面出错了</p>
-            <p className="mb-4 max-w-md text-sm break-all text-zinc-500">{String(this.state.err)}</p>
-            <button className="rounded-md bg-zinc-800 px-3 py-1.5 text-sm" onClick={() => this.setState({ err: null })}>
+            <p className="mb-4 max-w-md text-sm break-all text-stone-500">{String(this.state.err)}</p>
+            <button className="rounded-md bg-stone-800 px-3 py-1.5 text-sm" onClick={() => this.setState({ err: null })}>
               重试
             </button>
           </div>