docs(intro): update documentation for multilingual support

Expand README and introduction to highlight multilingual features,
including language-aware narration and highlighting. Update landing
page to reflect multilingual capabilities in descriptions, keywords,
and UI labels.

README.md

@@ -10,7 +10,7 @@
 
 # 📄🔊 OpenReader
 
-OpenReader is an open source, self-host-friendly text-to-speech document reader built with Next.js for **EPUB, PDF, TXT, MD, and DOCX** with synchronized read-along playback.
+OpenReader is an open source, self-host-friendly text-to-speech document reader built with Next.js for **EPUB, PDF, TXT, MD, and DOCX** with multilingual, synchronized read-along playback.
 
 > Previously named **OpenReader-WebUI**.
 
@@ -22,6 +22,7 @@ OpenReader is an open source, self-host-friendly text-to-speech document reader
 - ⏱️ **Word-by-word highlighting** via ONNX Whisper alignment through the compute worker control plane (NATS JetStream-backed).
 - ⚡ **Segment-based read-along** for EPUB, PDF, TXT, MD, and DOCX — sentence-aware TTS with cached audio segments, background preloading, and resumable playback.
 - 🎯 **Multi-provider TTS** — self-hosted OpenAI-compatible servers (Kokoro-FastAPI, KittenTTS-FastAPI, Orpheus-FastAPI) or cloud APIs (OpenAI, Replicate, DeepInfra).
+- 🌐 **Multilingual support** — choose a document language for language-aware narration and highlighting. Available languages depend on the configured TTS provider and voice.
 - 🎧 **Audiobook export** in `m4b`/`mp3` with resumable chapter processing.
 - 🗂️ **Flexible backend** — embedded SeaweedFS or S3-compatible storage, SQLite or Postgres, server library import, and device sync.
 - 🐳 **Self-host friendly** — Docker (amd64/arm64), built-in auth/session support, and automatic startup migrations.

docs-site/docs/introduction.md

@@ -4,7 +4,7 @@ title: Introduction
 slug: /
 ---
 
-OpenReader is an open source text-to-speech document reader built with Next.js. It provides a read-along experience with narration for **EPUB, PDF, TXT, MD, and DOCX documents**.
+OpenReader is an open source text-to-speech document reader built with Next.js. It provides a multilingual read-along experience with narration for **EPUB, PDF, TXT, MD, and DOCX documents**.
 
 > Previously named **OpenReader-WebUI**.
 
@@ -21,6 +21,9 @@ It supports multiple TTS providers including OpenAI, Replicate, DeepInfra, and c
 - 🎯 **Multi-Provider TTS Support**
   - Self-hosted: [**Kokoro-FastAPI**](https://github.com/remsky/Kokoro-FastAPI) (multi-voice combinations), [**KittenTTS-FastAPI**](https://github.com/richardr1126/KittenTTS-FastAPI), [**Orpheus-FastAPI**](https://github.com/Lex-au/Orpheus-FastAPI), or any custom OpenAI-compatible endpoint
   - Cloud: [**OpenAI**](https://platform.openai.com/docs/pricing#transcription-and-speech) (`tts-1`, `tts-1-hd`, `gpt-4o-mini-tts`), [**Replicate**](https://replicate.com/explore) (built-in catalog + any model ID), [**DeepInfra**](https://deepinfra.com/models/text-to-speech) (Kokoro-82M and others)
+- 🌐 **Multilingual Support**
+  - Choose a document language for language-aware narration and highlighting
+  - Available languages depend on the configured provider, model, and voice
 - 🎧 **Audiobook Export** in `m4b`/`mp3` with resumable chapter generation
 - 🗂️ **Flexible Backend** — embedded SeaweedFS or S3-compatible storage, SQLite or Postgres, server library import, and device sync
 - 🔐 **Auth and User Isolation** — auth is required in v4+, with optional anonymous auth sessions for guest flows

src/app/(public)/page.tsx

@@ -6,9 +6,9 @@ import { ButtonAnchor, ButtonLink } from '@/components/ui';
 export const metadata: Metadata = {
   title: 'Open Source Read-Along Workspace',
   description:
-    'OpenReader converts EPUB, PDF, TXT, MD, and DOCX files into synchronized read-along audio with multi-provider text-to-speech support.',
+    'OpenReader converts EPUB, PDF, TXT, MD, and DOCX files into multilingual, synchronized read-along audio with multi-provider text-to-speech support.',
   keywords:
-    'OpenReader, document reader, PDF read aloud, EPUB read aloud, text to speech, OpenAI compatible TTS, self-hosted reader',
+    'OpenReader, document reader, multilingual text to speech, PDF read aloud, EPUB read aloud, OpenAI compatible TTS, self-hosted reader',
   alternates: {
     canonical: '/',
   },
@@ -19,7 +19,7 @@ export const metadata: Metadata = {
     siteName: 'OpenReader',
     title: 'OpenReader | Read documents with synchronized audio',
     description:
-      'Upload documents and turn them into a synchronized listening experience with word-level highlighting and audiobook export.',
+      'Upload documents and turn them into a multilingual, synchronized listening experience with word-level highlighting and audiobook export.',
     images: [
       {
         url: '/web-app-manifest-512x512.png',
@@ -91,7 +91,7 @@ export default async function LandingPage() {
             <p className="public-hero-copy">
               OpenReader turns EPUB, PDF, TXT, Markdown, and DOCX into a
               synchronized read-along surface, reading your original file in a
-              native viewer with genuine text-to-speech, word-level
+              native viewer with multilingual text-to-speech, language-aware
               highlighting, and audiobook export. It&rsquo;s open source, and
               entirely yours to self-host.
             </p>
@@ -126,7 +126,7 @@ export default async function LandingPage() {
               <span className="public-reader-dot" data-tone="b" />
               <span className="public-reader-dot" data-tone="c" />
               <span className="public-reader-file">wizard-of-oz.epub</span>
-              <span className="public-reader-voice">Kokoro · af_sky</span>
+              <span className="public-reader-voice">English · Kokoro · af_sky</span>
             </div>
 
             <div className="public-reader-body">
@@ -203,7 +203,8 @@ export default async function LandingPage() {
               <p>
                 Choose a provider and model: hosted OpenAI, Replicate, or
                 DeepInfra, or your own self-hosted Kokoro, KittenTTS, or Orpheus
-                server. Set the speed to your pace.
+                server. Set the document language, choose a compatible voice,
+                and adjust the speed to your pace.
               </p>
             </li>
             <li className="public-step">
@@ -251,11 +252,11 @@ export default async function LandingPage() {
             </article>
 
             <article className="public-feature">
-              <span className="public-feature-kicker">Voices</span>
-              <h3>Multi-provider TTS</h3>
+              <span className="public-feature-kicker">Languages</span>
+              <h3>Multilingual support</h3>
               <p>
-                Mix cloud APIs with OpenAI-compatible local servers. Bring your
-                own keys and endpoints, with no lock-in to a single vendor.
+                Choose a document language for language-aware narration,
+                highlighting, and compatible voice selection.
               </p>
             </article>