Improve quiz TTS and Android release build

2026-05-12 01:01:01 +02:00 · 2026-05-12 01:01:01 +02:00 · fdebda993c
commit fdebda993c
parent d59c8bed6f
22 changed files with 541 additions and 204 deletions
--- a/.forgejo/workflows/mobile-android.yml
+++ b/.forgejo/workflows/mobile-android.yml
@ -0,0 +1,116 @@
+name: Mobile Android Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+  workflow_dispatch:
+    inputs:
+      release_name:
+        description: 'Forgejo release name'
+        required: false
+        default: 'Manual Android Build'
+
+jobs:
+  android-release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+
+      - name: Set up Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: '17'
+
+      - name: Validate Android signing secrets
+        env:
+          ANDROID_KEYSTORE_BASE64: ${{ secrets.ANDROID_KEYSTORE_BASE64 }}
+          ANDROID_KEYSTORE_PASSWORD: ${{ secrets.ANDROID_KEYSTORE_PASSWORD }}
+          ANDROID_KEY_ALIAS: ${{ secrets.ANDROID_KEY_ALIAS }}
+          ANDROID_KEY_PASSWORD: ${{ secrets.ANDROID_KEY_PASSWORD }}
+        run: |
+          test -n "$ANDROID_KEYSTORE_BASE64"
+          test -n "$ANDROID_KEYSTORE_PASSWORD"
+          test -n "$ANDROID_KEY_ALIAS"
+          test -n "$ANDROID_KEY_PASSWORD"
+
+      - name: Build frontend
+        working-directory: frontend
+        run: |
+          npm ci
+          npm run build
+
+      - name: Install mobile dependencies
+        working-directory: mobile
+        run: npm ci
+
+      - name: Decode Android keystore
+        env:
+          ANDROID_KEYSTORE_BASE64: ${{ secrets.ANDROID_KEYSTORE_BASE64 }}
+        run: |
+          mkdir -p mobile/android/keystore
+          printf '%s' "$ANDROID_KEYSTORE_BASE64" | base64 -d > mobile/android/keystore/release.jks
+
+      - name: Sync Capacitor Android
+        working-directory: mobile
+        run: npx cap sync android
+
+      - name: Build signed release APK
+        working-directory: mobile/android
+        env:
+          ANDROID_KEYSTORE_FILE: ${{ github.workspace }}/mobile/android/keystore/release.jks
+          ANDROID_KEYSTORE_PASSWORD: ${{ secrets.ANDROID_KEYSTORE_PASSWORD }}
+          ANDROID_KEY_ALIAS: ${{ secrets.ANDROID_KEY_ALIAS }}
+          ANDROID_KEY_PASSWORD: ${{ secrets.ANDROID_KEY_PASSWORD }}
+        run: |
+          chmod +x gradlew
+          ./gradlew assembleRelease
+          mkdir -p ../../dist
+          cp app/build/outputs/apk/release/app-release.apk ../../dist/pedshub-${GITHUB_REF_NAME:-manual}.apk
+
+      - name: Create Forgejo release and upload APK
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          RELEASE_NAME: ${{ inputs.release_name }}
+        run: |
+          set -eu
+          tag="${GITHUB_REF_NAME:-manual-${GITHUB_RUN_NUMBER}}"
+          apk="dist/pedshub-${tag}.apk"
+          name="${RELEASE_NAME:-PedsHub Android ${tag}}"
+          body="Automated signed Android APK build for ${tag}."
+          api="${GITHUB_API_URL}/repos/${GITHUB_REPOSITORY}"
+
+          release_json=$(curl -fsS "${api}/releases/tags/${tag}" \
+            -H "Authorization: token ${GITHUB_TOKEN}" || true)
+          if [ -z "$release_json" ]; then
+            payload=$(python3 - <<PY
+          import json
+          print(json.dumps({
+              "tag_name": "${tag}",
+              "target_commitish": "${GITHUB_SHA}",
+              "name": "${name}",
+              "body": "${body}",
+              "draft": False,
+              "prerelease": False,
+          }))
+          PY
+          )
+            release_json=$(curl -fsS -X POST "${api}/releases" \
+              -H "Authorization: token ${GITHUB_TOKEN}" \
+              -H "Content-Type: application/json" \
+              -d "$payload")
+          fi
+
+          release_id=$(printf '%s' "$release_json" | python3 -c 'import json,sys; print(json.load(sys.stdin)["id"])')
+          curl -fsS -X POST "${api}/releases/${release_id}/assets?name=$(basename "$apk")" \
+            -H "Authorization: token ${GITHUB_TOKEN}" \
+            -H "Content-Type: application/vnd.android.package-archive" \
+            --data-binary "@${apk}"
--- a/README.md
+++ b/README.md
@ -10,7 +10,7 @@ AI-powered pediatric learning platform. Upload PDF study materials, automaticall
 - **AI Tutor (TeachChat)**: Ask follow-up questions mid-study — AI knows the current question, correct answer, and related content. Renders markdown tables, code, and follow-up suggestion chips.
 - **Tag Classification**: AI classifies questions with subjects, diseases, and keywords — filter your question bank by any combination of tags
 - **Multi-Category Filtering**: Filter questions by question category, tags, or quiz source — combine multiple filters for precise study sets
- **Text-to-Speech**: OpenAI TTS, AWS Polly, ElevenLabs, Google Cloud — voice selection per quiz
+- **Text-to-Speech**: LiteLLM-routed local TTS, OpenAI TTS, ElevenLabs, Google Cloud — voice selection per quiz
 - **Semantic Search**: pgvector embeddings — finds questions by meaning, not just keywords
 - **Question Bank**: All questions searchable, filterable by category and tags, with inline study mode
 - **Image Validation**: AI `has_figure` gating — only links extracted images to questions the AI flagged as having a figure, preventing mismatched images
@ -36,7 +36,7 @@ AI-powered pediatric learning platform. Upload PDF study materials, automaticall
 | AI/LLM | LiteLLM proxy (Claude, Gemini, GPT, Bedrock, and more) |
 | Embeddings | Configurable — any LiteLLM proxy model or direct AWS Bedrock (1024-dim) |
 | Document vectors | ChromaDB |
-| TTS | OpenAI (direct), AWS Polly, ElevenLabs, Google Cloud TTS |
+| TTS | LiteLLM-routed local TTS, OpenAI (direct), ElevenLabs, Google Cloud TTS |
 | Queue | Celery + Redis (4 fork workers) |
 | Email | SMTP (smtp2go or any SMTP server) |
 | Bot protection | Cloudflare Turnstile (runtime-configurable, no rebuild needed) |
@ -311,7 +311,6 @@ Accessible at `/admin` for admin users. Three tabs:

 ### More Settings
 - **Public Registration** — enable/disable new user sign-ups
- **AWS Polly** — global enable/disable toggle for all Polly voices
 - **Classify Questions** — trigger AI tag classification for all untagged questions (runs as background task)
 - **Embedding Model** — set the model used for semantic search vectors:
  - Type a model name and click **Save**, or click **Search LiteLLM** to browse proxy models
@ -461,9 +460,8 @@ The landing page at `/home` uses the shared `Navbar` component. When not logged

 ## TTS Providers

-| Provider | Model ID format | Key needed |
+| Provider | Model/voice ID format | Key needed |
 |---|---|---|
-| OpenAI | `tts-1:alloy`, `tts-1:nova`, `tts-1-hd:*` | `OPENAI_API_KEY` |
-| AWS Polly | `polly/Joanna`, `polly/Matthew`, `polly/Amy` | `AWS_ACCESS_KEY_ID` + IAM `polly:SynthesizeSpeech` |
-| ElevenLabs | `elevenlabs/<voice-id>` | `ELEVENLABS_API_KEY` |
-| Google Cloud | `google/<voice-name>` | `GOOGLE_TTS_API_KEY` |
+| Kokoro via LiteLLM | `local-kokoro-tts:am_adam`, `local-kokoro-tts:af_bella` | `LITELLM_API_KEY` |
+
+The part before `:` is the LiteLLM speech model route. The part after `:` is the Kokoro speaker voice.
--- a/backend/app/main.py
+++ b/backend/app/main.py
@ -68,6 +68,8 @@ def seed_admin():

 def seed_default_models():
    """Seed default AI model configs if none exist."""
+    from sqlalchemy import text
+
    from app.models.ai_model_config import AIModelConfig
    db = SessionLocal()
    try:
@ -91,8 +93,12 @@ def seed_default_models():

        # Always ensure LiteLLM-routed local speech models exist (idempotent).
        tts_voices = [
-            ("Kokoro TTS (LiteLLM)", "local-kokoro-tts", True),
-            ("Qwen3 TTS (LiteLLM)", "local-qwen3-tts", False),
+            ("Kokoro Adam", "local-kokoro-tts:am_adam", True),
+            ("Kokoro Michael", "local-kokoro-tts:am_michael", False),
+            ("Kokoro Bella", "local-kokoro-tts:af_bella", False),
+            ("Kokoro Nicole", "local-kokoro-tts:af_nicole", False),
+            ("Kokoro Emma", "local-kokoro-tts:bf_emma", False),
+            ("Kokoro Lewis", "local-kokoro-tts:bm_lewis", False),
        ]
        stt_models = [
            ("Parakeet STT (LiteLLM)", "local-parakeet-v3", True),
@ -101,30 +107,31 @@ def seed_default_models():
        ]
        # Deactivate external/direct legacy TTS entries; speech should route through LiteLLM.
        for old in db.query(AIModelConfig).filter(AIModelConfig.task == "tts").all():
-            if old.model_id and old.model_id.startswith(("tts-", "openai/", "elevenlabs/", "eleven_labs/", "google/", "polly/", "sherpa/")):
+            if old.model_id and not old.model_id.startswith("local-"):
+                old.is_active = False
+                old.is_default = False
+            if old.model_id == "local-kokoro-tts":
                old.is_active = False
                old.is_default = False
            if old.model_id == "local-chatterbox-turbo":
                old.is_active = False
                old.is_default = False
-
-        has_default_tts = db.query(AIModelConfig).filter(
-            AIModelConfig.task == "tts", AIModelConfig.is_default == True, AIModelConfig.is_active == True,
-        ).first() is not None
+            if old.model_id == "local-qwen3-tts":
+                old.is_active = False
+                old.is_default = False

        for name, model_id, _ in tts_voices:
-            exists = db.query(AIModelConfig).filter(AIModelConfig.model_id == model_id).first()
-            if not exists:
-                is_def = not has_default_tts
-                db.add(AIModelConfig(name=name, model_id=model_id, task="tts", is_active=True, is_default=is_def))
-                if is_def:
-                    has_default_tts = True
+            db.execute(text("""
+                INSERT INTO ai_model_configs (name, model_id, task, is_active, is_default, created_at)
+                VALUES (:name, :model_id, 'tts', true, false, NOW())
+                ON CONFLICT (model_id, task) DO NOTHING
+            """), {"name": name, "model_id": model_id})

        # LiteLLM Kokoro is the intended default for read-aloud; admins can change it later.
        db.query(AIModelConfig).filter(AIModelConfig.task == "tts").update({"is_default": False})
        local_default = db.query(AIModelConfig).filter(
            AIModelConfig.task == "tts",
-            AIModelConfig.model_id == "local-kokoro-tts",
+            AIModelConfig.model_id == "local-kokoro-tts:am_adam",
        ).first()
        if local_default:
            local_default.is_active = True
@ -143,7 +150,11 @@ def seed_default_models():
                ).first()
                if not exists:
                    is_def = preferred_default and not has_default
-                    db.add(AIModelConfig(name=name, model_id=model_id, task=task, is_active=True, is_default=is_def))
+                    db.execute(text("""
+                        INSERT INTO ai_model_configs (name, model_id, task, is_active, is_default, created_at)
+                        VALUES (:name, :model_id, :task, true, :is_default, NOW())
+                        ON CONFLICT (model_id, task) DO NOTHING
+                    """), {"name": name, "model_id": model_id, "task": task, "is_default": is_def})
                    if is_def:
                        has_default = True
        db.commit()
--- a/backend/app/routers/admin.py
+++ b/backend/app/routers/admin.py
@ -139,6 +139,7 @@ def list_available_models(
 class LiteLLMSearchRequest(BaseModel):
    api_key: str | None = None
    api_base: str | None = None
+    mode: str | None = None


@router.post("/litellm/models")
@ -155,8 +156,16 @@ def search_litellm_models(
    if base:
        try:
            headers = {"Authorization": f"Bearer {key}"} if key else {}
-            resp = httpx.post(f"{base}/v1/models", headers=headers, timeout=10) if False else \
-                   httpx.get(f"{base}/v1/models", headers=headers, timeout=10)
+            if data.mode:
+                info_base = base.rstrip("/").removesuffix("/v1")
+                resp = httpx.get(f"{info_base}/model/info", headers=headers, timeout=10)
+                resp.raise_for_status()
+                models = sorted([
+                    m.get("model_name") for m in resp.json().get("data", [])
+                    if m.get("model_name") and (m.get("model_info") or {}).get("mode") == data.mode
+                ])
+                return {"models": models, "source": info_base, "mode": data.mode}
+            resp = httpx.get(f"{base}/v1/models", headers=headers, timeout=10)
            resp.raise_for_status()
            models = sorted([m["id"] for m in resp.json().get("data", [])])
            return {"models": models, "source": base}
@ -326,6 +335,47 @@ class TTSVoiceSearchRequest(BaseModel):
    region: str | None = None


+KOKORO_VOICE_FALLBACKS = [
+    ("am_adam", "Kokoro Adam"),
+    ("am_michael", "Kokoro Michael"),
+    ("af_bella", "Kokoro Bella"),
+    ("af_nicole", "Kokoro Nicole"),
+    ("bf_emma", "Kokoro Emma"),
+    ("bm_lewis", "Kokoro Lewis"),
+]
+
+
+def _kokoro_voice_options(model_name: str) -> list[dict]:
+    base = settings.LOCAL_SPEECH_GATEWAY_URL.rstrip("/")
+    voices = []
+    friendly_names = {voice_id: name for voice_id, name in KOKORO_VOICE_FALLBACKS}
+    if base:
+        try:
+            resp = httpx.get(f"{base}/v1/audio/voices", timeout=10)
+            resp.raise_for_status()
+            voices = [
+                v for v in resp.json().get("voices", [])
+                if v.get("profile") == "kokoro" and v.get("voice")
+            ]
+        except Exception:
+            voices = []
+
+    if not voices:
+        voices = [
+            {"voice": voice_id, "name": name, "profile": "kokoro"}
+            for voice_id, name in KOKORO_VOICE_FALLBACKS
+        ]
+
+    return [
+        {
+            "model_id": f"{model_name}:{v['voice']}",
+            "name": friendly_names.get(v["voice"], v.get("name") or f"Kokoro {v['voice']}"),
+            "labels": {"provider": "litellm", "model": model_name, "voice": v["voice"]},
+        }
+        for v in voices
+    ]
+
+
@router.post("/tts/voices")
 def search_tts_voices(
    data: TTSVoiceSearchRequest,
@ -351,15 +401,20 @@ def search_tts_voices(
            resp = httpx.get(f"{base}/model/info", headers=headers, timeout=10)
            resp.raise_for_status()
            models = resp.json().get("data", [])
-            return {"voices": [
-                {
-                    "model_id": m.get("model_name"),
-                    "name": m.get("model_name"),
+            voices = []
+            for m in models:
+                model_name = m.get("model_name")
+                if not model_name or (m.get("model_info") or {}).get("mode") != "audio_speech":
+                    continue
+                if model_name == "local-kokoro-tts":
+                    voices.extend(_kokoro_voice_options(model_name))
+                    continue
+                voices.append({
+                    "model_id": model_name,
+                    "name": model_name,
                    "labels": {"provider": "litellm", "mode": "audio_speech"},
-                }
-                for m in models
-                if m.get("model_name") and (m.get("model_info") or {}).get("mode") == "audio_speech"
-            ]}
+                })
+            return {"voices": voices}
        except HTTPException:
            raise
        except Exception as e:
@ -379,12 +434,10 @@ def get_settings(admin: User = Depends(require_admin)):
        r = redis_lib.from_url(settings.REDIS_URL, decode_responses=True)
        registration_enabled = r.get("settings:registration_enabled")
        embedding_model = r.get("settings:embedding_model")
-        polly_enabled = r.get("settings:polly_enabled")
        sso_only = r.get("settings:sso_only")
        return {
            "registration_enabled": registration_enabled != "false",
            "embedding_model": embedding_model or settings.LITELLM_EMBEDDING_MODEL or "",
-            "polly_enabled": polly_enabled != "false",
            "sso_only": sso_only == "true",
            "sso_configured": bool(settings.OIDC_PROVIDER_URL and settings.OIDC_CLIENT_ID),
            "sso_provider_name": settings.OIDC_PROVIDER_NAME,
@ -393,7 +446,6 @@ def get_settings(admin: User = Depends(require_admin)):
        return {
            "registration_enabled": True,
            "embedding_model": settings.LITELLM_EMBEDDING_MODEL or "",
-            "polly_enabled": True,
            "sso_only": False,
            "sso_configured": bool(settings.OIDC_PROVIDER_URL and settings.OIDC_CLIENT_ID),
            "sso_provider_name": settings.OIDC_PROVIDER_NAME,
@ -417,10 +469,6 @@ def update_settings(
        if "embedding_model" in settings_data:
            r.set("settings:embedding_model", settings_data["embedding_model"])

-        if "polly_enabled" in settings_data:
-            value = "true" if settings_data["polly_enabled"] else "false"
-            r.set("settings:polly_enabled", value)
-
        if "sso_only" in settings_data:
            value = "true" if settings_data["sso_only"] else "false"
            r.set("settings:sso_only", value)
--- a/backend/app/routers/tts.py
+++ b/backend/app/routers/tts.py
@ -3,7 +3,6 @@ from fastapi.responses import Response
 from pydantic import BaseModel
 from sqlalchemy.orm import Session

-from app.config import settings
 from app.database import get_db
 from app.models.user import User
 from app.models.ai_model_config import AIModelConfig
@ -32,16 +31,6 @@ def _task_model(db: Session, task: str, fallback: str) -> tuple[str, str | None]
    return fallback, None


-def _polly_enabled() -> bool:
-    try:
-        import redis as redis_lib
-        r = redis_lib.from_url(settings.REDIS_URL, decode_responses=True)
-        val = r.get("settings:polly_enabled")
-        return val != "false"
-    except Exception:
-        return True
-
-
 def _default_tts_model(db: Session) -> tuple[str, str | None]:
    config = db.query(AIModelConfig).filter(
        AIModelConfig.task == "tts",
@ -51,7 +40,7 @@ def _default_tts_model(db: Session) -> tuple[str, str | None]:
    ).first()
    if config:
        return config.model_id, config.api_key or None
-    return "local-kokoro-tts", None
+    return "local-kokoro-tts:am_adam", None


@router.get("/voices")
@ -65,8 +54,6 @@ def get_voices(
        AIModelConfig.is_active == True,
        AIModelConfig.model_id.like("local-%"),
    )
-    if not _polly_enabled():
-        query = query.filter(~AIModelConfig.model_id.like("polly/%"))
    db_models = query.order_by(AIModelConfig.is_default.desc(), AIModelConfig.name).all()
    return [{"id": m.model_id, "name": m.name, "is_default": m.is_default} for m in db_models]

@ -92,11 +79,16 @@ def text_to_speech(
    text = request.text[:2000]

    if request.voice and request.voice.startswith("local-"):
-        if request.voice.startswith("polly/") and not _polly_enabled():
-            raise HTTPException(status_code=400, detail="AWS Polly is currently disabled")
-        config = db.query(AIModelConfig).filter(AIModelConfig.model_id == request.voice).first()
-        model_id = config.model_id if config else request.voice
-        api_key = config.api_key if (config and config.api_key) else None
+        config = db.query(AIModelConfig).filter(
+            AIModelConfig.task == "tts",
+            AIModelConfig.is_active == True,
+            AIModelConfig.model_id == request.voice,
+        ).first()
+        if not config:
+            model_id, api_key = _default_tts_model(db)
+        else:
+            model_id = config.model_id
+            api_key = config.api_key or None
    else:
        model_id, api_key = _default_tts_model(db)

--- a/backend/app/services/ai_service.py
+++ b/backend/app/services/ai_service.py
@ -380,16 +380,15 @@ def generate_tts_audio(
    model_id: str | None = None,
    api_key: str | None = None,
 ) -> bytes | None:
-    """Generate TTS audio. Supports local Sherpa, OpenAI, ElevenLabs, Google Cloud TTS, and AWS Polly.
+    """Generate TTS audio. Supports local LiteLLM, local Sherpa, OpenAI, ElevenLabs, and Google Cloud TTS.

    model_id conventions:
      tts-1:alloy          → OpenAI TTS (voice after colon)
      tts-1-hd:nova        → OpenAI TTS HD
      elevenlabs/<voice>   → ElevenLabs
      google/<voice_name>  → Google Cloud TTS (e.g. google/en-US-Wavenet-D)
-      polly/<VoiceId>      → AWS Polly Neural (e.g. polly/Joanna)
      sherpa/<profile>:<voice> → Local speech gateway (e.g. sherpa/kokoro:am_adam)
-      local-<model>        → Local LiteLLM TTS model (e.g. local-chatterbox-turbo)
+      local-<model>:<voice> → Local LiteLLM TTS model + voice (e.g. local-kokoro-tts:am_adam)
    """
    import httpx, base64

@ -397,6 +396,10 @@ def generate_tts_audio(

    # ── Local LiteLLM TTS models ─────────────────────────────────
    if use_model.startswith("local-"):
+        local_model = use_model
+        local_voice = "am_adam" if use_model.startswith("local-kokoro-tts") else "alloy"
+        if ":" in use_model:
+            local_model, local_voice = use_model.split(":", 1)
        key = api_key or settings.LITELLM_API_KEY
        base = (settings.LITELLM_API_BASE or "").rstrip("/").removesuffix("/v1")
        if not base:
@ -406,7 +409,7 @@ def generate_tts_audio(
            resp = httpx.post(
                f"{base}/v1/audio/speech",
                headers={"Authorization": f"Bearer {key}", "Content-Type": "application/json"} if key else {"Content-Type": "application/json"},
-                json={"model": use_model, "input": text, "voice": "alloy", "response_format": "mp3"},
+                json={"model": local_model, "input": text, "voice": local_voice, "response_format": "mp3"},
                timeout=90,
            )
            resp.raise_for_status()
@ -480,34 +483,6 @@ def generate_tts_audio(
            logger.error(f"Google TTS failed: {e}")
            return None

-    # ── AWS Polly ───────────────────────────────────────────────
-    if use_model.startswith("polly/"):
-        voice_id = use_model[len("polly/"):]
-        access_key = api_key or settings.AWS_ACCESS_KEY_ID
-        secret_key = settings.AWS_SECRET_ACCESS_KEY
-        region = settings.AWS_REGION or "us-east-1"
-        if not access_key or not secret_key:
-            logger.error("AWS credentials not configured (AWS_ACCESS_KEY_ID / AWS_SECRET_ACCESS_KEY)")
-            return None
-        try:
-            import boto3
-            polly = boto3.client(
-                "polly",
-                aws_access_key_id=access_key,
-                aws_secret_access_key=secret_key,
-                region_name=region,
-            )
-            response = polly.synthesize_speech(
-                Text=text,
-                OutputFormat="mp3",
-                VoiceId=voice_id,
-                Engine="neural",
-            )
-            return response["AudioStream"].read()
-        except Exception as e:
-            logger.error(f"AWS Polly TTS failed: {e}")
-            return None
-
    # ── OpenAI (default) ────────────────────────────────────────
    # model_id may encode voice as "tts-1:nova", "tts-1-hd:alloy", etc.
    clean_model = use_model.replace("openai/", "")
--- a/docs/api-reference.md
+++ b/docs/api-reference.md
@ -705,7 +705,7 @@ Convert text to speech audio.
  }
  ```
 - **Response:** Binary `audio/mpeg` data
- **Notes:** Supports OpenAI TTS (`tts-1:alloy`), ElevenLabs (`elevenlabs/<voice_id>`), Google Cloud TTS (`google/<voice_name>`), and AWS Polly (`polly/<VoiceId>`).
+- **Notes:** Supports LiteLLM-routed local TTS voices, e.g. `local-kokoro-tts:am_adam`. The prefix before `:` is the LiteLLM model route; the suffix is the speaker voice sent to that route.

 ---

@ -993,14 +993,14 @@ Discover available TTS voices from a provider.
 Get system settings (registration enabled, embedding model, Polly enabled).

 - **Auth:** Admin
- **Response:** `{"registration_enabled": bool, "embedding_model": "string", "polly_enabled": bool}`
+- **Response:** `{"registration_enabled": bool, "embedding_model": "string"}`

 #### PUT `/api/admin/settings`

 Update system settings.

 - **Auth:** Admin
- **Request body:** `{"registration_enabled": bool, "embedding_model": "string", "polly_enabled": bool}`
+- **Request body:** `{"registration_enabled": bool, "embedding_model": "string"}`
 - **Response:** `{"success": true, "message": "Settings updated"}`

 ### Embedding Management
--- a/docs/services.md
+++ b/docs/services.md
@ -84,7 +84,6 @@ Multi-provider TTS generation. Provider is determined by `model_id` convention:
 | `tts-1-hd:nova` | OpenAI TTS HD | Voice after colon |
 | `elevenlabs/<voice_id>` | ElevenLabs | Uses `eleven_turbo_v2_5` model |
 | `google/<voice_name>` | Google Cloud TTS | Parses language code from voice name |
-| `polly/<VoiceId>` | AWS Polly Neural | e.g. `polly/Joanna` |

 **OpenAI key resolution order:** per-model API key > `OPENAI_API_KEY` (direct) > `LITELLM_API_KEY` (proxy). When using `OPENAI_API_KEY`, calls go directly to `api.openai.com`; otherwise uses `LITELLM_API_BASE`.

--- a/frontend/src/index.css
+++ b/frontend/src/index.css
@ -61,7 +61,7 @@
  --navbar-fg:     #f0e8d8;
  --badge-radius:  4px;
  --font-body:     'Source Serif 4', Georgia, serif;
-  --font-heading:  'Playfair Display', 'Source Serif 4', serif;
+  --font-heading:  'Inter', ui-sans-serif, system-ui, -apple-system, sans-serif;
  --font-ui:       'Inter', system-ui, sans-serif;
 }

@ -71,9 +71,9 @@ body[data-theme="markdown"] {
  font-size: 15.5px;
  line-height: 1.7;
 }
-[data-theme="markdown"] .navbar .logo { color: #e0a84a; font-family: var(--font-heading); letter-spacing: 0; }
-[data-theme="markdown"] h1 { font-family: var(--font-heading); font-weight: 700; letter-spacing: -0.02em; }
-[data-theme="markdown"] h2, [data-theme="markdown"] .card h2 { font-family: var(--font-heading); font-weight: 600; }
+[data-theme="markdown"] .navbar .logo { color: #e0a84a; font-family: var(--font-heading); letter-spacing: -0.02em; }
+[data-theme="markdown"] h1 { font-family: var(--font-heading); font-weight: 760; letter-spacing: -0.03em; line-height: 1.12; }
+[data-theme="markdown"] h2, [data-theme="markdown"] .card h2 { font-family: var(--font-heading); font-weight: 680; letter-spacing: -0.02em; line-height: 1.2; }
 [data-theme="markdown"] h3 { font-family: var(--font-ui); font-weight: 600; }
 [data-theme="markdown"] .card h2 { border-bottom: 1px solid var(--border); padding-bottom: 10px; margin-bottom: 18px; }
 [data-theme="markdown"] .question-card { border-left: 3px solid var(--primary); }
@ -135,6 +135,34 @@ body {
 }
 .card h2 { margin-bottom: 16px; font-size: 1.15rem; color: var(--text); font-weight: 600; }

+.quiz-header-card .quiz-header-title,
+[data-theme="markdown"] .quiz-header-card .quiz-header-title {
+  margin: 0 0 2px;
+  padding: 0;
+  border: 0;
+  font-family: var(--font-ui, 'Inter', ui-sans-serif, system-ui, -apple-system, sans-serif);
+  font-size: clamp(0.98rem, 1.8vw, 1.14rem);
+  font-weight: 720;
+  line-height: 1.18;
+  letter-spacing: -0.025em;
+}
+
+.quiz-nav-controls {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  gap: 8px;
+  margin-top: 14px;
+}
+.quiz-nav-controls-top {
+  margin: -4px 0 16px;
+  padding: 10px 12px;
+  background: color-mix(in srgb, var(--card-bg) 92%, transparent);
+  border: var(--card-border);
+  border-radius: var(--card-radius);
+  box-shadow: var(--card-shadow);
+}
+
 /* ── Buttons ────────────────────────────────────────────────── */
 .btn {
  display: inline-flex; align-items: center; gap: 6px;
@ -182,6 +210,27 @@ body {
  box-shadow: var(--card-shadow);
 }
 .question-card h3 { font-size: 1.05rem; line-height: 1.6; margin-bottom: 20px; color: var(--text); font-weight: 600; }
+.manual-highlight-toolbar { display: inline-flex; gap: 6px; flex-wrap: wrap; align-items: center; }
+.manual-highlight-segment { user-select: text; -webkit-user-select: text; }
+.manual-highlight-active {
+  background: linear-gradient(transparent 38%, rgba(253, 224, 71, 0.72) 38%);
+  border-radius: 2px;
+  box-decoration-break: clone;
+  -webkit-box-decoration-break: clone;
+}
+.speech-highlight-active {
+  background: rgba(96, 165, 250, 0.18);
+  box-shadow: inset 0 -2px 0 rgba(59, 130, 246, 0.72);
+  border-radius: 3px;
+  padding: 0 2px;
+  box-decoration-break: clone;
+  -webkit-box-decoration-break: clone;
+}
+.manual-highlight-active.speech-highlight-active {
+  background:
+    linear-gradient(transparent 38%, rgba(253, 224, 71, 0.72) 38%),
+    rgba(96, 165, 250, 0.18);
+}

 /* Options */
 .question-card .options { display: flex; flex-direction: column; gap: 10px; }
@ -189,7 +238,7 @@ body {
  display: flex; align-items: center; gap: 12px;
  padding: 13px 16px; border: 1.5px solid var(--border); border-radius: 8px;
  cursor: pointer; transition: border-color 0.12s, background 0.12s;
-  background: var(--option-bg); font-size: 0.9rem; color: var(--text); user-select: none;
+  background: var(--option-bg); font-size: 0.9rem; color: var(--text); user-select: text;
  -webkit-tap-highlight-color: transparent; touch-action: manipulation;
 }
 .question-card .option:hover { background: var(--option-hover); border-color: var(--text-subtle); }
@ -349,6 +398,9 @@ body {
  /* Mobile quiz: hide sidebar, show toggle */
  .quiz-sidebar { display: none; }
  .quiz-nav-toggle { display: inline-flex; }
+  .quiz-nav-controls { gap: 6px; }
+  .quiz-nav-controls .btn { flex: 1; justify-content: center; padding-left: 10px; padding-right: 10px; }
+  .quiz-nav-controls .quiz-nav-toggle { flex: 0 0 auto; }
 }

 /* ── Lesson content (markdown/HTML) ───────────────────────────── */
--- a/frontend/src/pages/AdminPage.jsx
+++ b/frontend/src/pages/AdminPage.jsx
@ -14,7 +14,7 @@ export default function AdminPage() {
  const [tab, setTab] = useState('models')
  const [users, setUsers] = useState([])
  const [models, setModels] = useState([])
-  const [settings, setSettings] = useState({ registration_enabled: true, embedding_model: '', polly_enabled: true })
+  const [settings, setSettings] = useState({ registration_enabled: true, embedding_model: '' })
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState('')
  const [success, setSuccess] = useState('')
@ -182,12 +182,11 @@ export default function AdminPage() {
  const searchEmbeddingModels = async () => {
    setEmbedSearchError('')
    setEmbedSearchResults([])
+    setEmbedSearchFilter('')
    setEmbedSearchLoading(true)
    try {
-      const res = await api.post('/admin/litellm/models', {})
-      const all = res.data.models || []
-      // Filter to likely embedding models
-      setEmbedSearchResults(all)
+      const res = await api.post('/admin/litellm/models', { mode: 'embedding' })
+      setEmbedSearchResults(res.data.models || [])
    } catch (err) {
      setEmbedSearchError(err.response?.data?.detail || 'Failed to query models')
    } finally {
@ -647,37 +646,6 @@ export default function AdminPage() {
              </label>
            </div>

-            {/* AWS Polly */}
-            <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', padding: '12px 0', borderBottom: '1px solid var(--border)' }}>
-              <div>
-                <strong style={{ display: 'block', marginBottom: 4 }}>AWS Polly Voices</strong>
-                <span style={{ fontSize: '0.85rem', color: 'var(--text-muted)' }}>
-                  Enable or disable AWS Polly TTS voices globally. Individual voices can still be toggled in the AI Models tab.
-                </span>
-              </div>
-              <label style={{ display: 'flex', alignItems: 'center', gap: 8, cursor: 'pointer' }}>
-                <input
-                  type="checkbox"
-                  checked={settings.polly_enabled}
-                  onChange={async (e) => {
-                    const enabled = e.target.checked
-                    setSettings(s => ({ ...s, polly_enabled: enabled }))
-                    try {
-                      await api.put('/admin/settings', { polly_enabled: enabled })
-                      setSuccess(`AWS Polly ${enabled ? 'enabled' : 'disabled'}`)
-                    } catch (err) {
-                      setError(err.response?.data?.detail || 'Failed to update setting')
-                      setSettings(s => ({ ...s, polly_enabled: !enabled }))
-                    }
-                  }}
-                  style={{ width: 'auto', accentColor: 'var(--primary)' }}
-                />
-                <span style={{ fontSize: '0.9rem', fontWeight: 600 }}>
-                  {settings.polly_enabled ? 'Enabled' : 'Disabled'}
-                </span>
-              </label>
-            </div>
-
            {/* SSO Only */}
            {settings.sso_configured && (
              <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'space-between', padding: '12px 0', borderBottom: '1px solid var(--border)' }}>
--- a/frontend/src/pages/QuizPage.jsx
+++ b/frontend/src/pages/QuizPage.jsx
@ -10,6 +10,97 @@ const QUESTION_HIGHLIGHT_WORDS = 8
 const OPTION_HIGHLIGHT_WORDS = 7
 const TTS_PRELOAD_AHEAD = 5

+function mergeTextRanges(ranges) {
+  const sorted = ranges
+    .filter(r => Number.isFinite(r.start) && Number.isFinite(r.end) && r.end > r.start)
+    .sort((a, b) => a.start - b.start || a.end - b.end)
+  const merged = []
+  sorted.forEach(range => {
+    const last = merged[merged.length - 1]
+    if (!last || range.start > last.end) {
+      merged.push({ start: range.start, end: range.end })
+    } else {
+      last.end = Math.max(last.end, range.end)
+    }
+  })
+  return merged
+}
+
+function removeTextRange(ranges, removeRange) {
+  const next = []
+  ranges.forEach(range => {
+    if (removeRange.end <= range.start || removeRange.start >= range.end) {
+      next.push(range)
+      return
+    }
+    if (removeRange.start > range.start) next.push({ start: range.start, end: removeRange.start })
+    if (removeRange.end < range.end) next.push({ start: removeRange.end, end: range.end })
+  })
+  return mergeTextRanges(next)
+}
+
+function getSpeechChunkRange(text, maxWords, activeChunk) {
+  if (activeChunk === null || activeChunk === undefined) return null
+  const words = []
+  const re = /\S+/g
+  let match
+  while ((match = re.exec(text || ''))) words.push({ start: match.index, end: match.index + match[0].length })
+  const startWord = activeChunk * maxWords
+  if (!words[startWord]) return null
+  const endWord = Math.min(startWord + maxWords - 1, words.length - 1)
+  return { start: words[startWord].start, end: words[endWord].end }
+}
+
+function getManualHighlightSelection() {
+  const selection = window.getSelection?.()
+  if (!selection || selection.rangeCount === 0 || !selection.toString().trim()) return null
+
+  const offsetFromNode = (node, offset) => {
+    const element = node.nodeType === Node.TEXT_NODE ? node.parentElement : node
+    const span = element?.closest?.('[data-manual-highlight-id]')
+    if (!span) return null
+    return {
+      id: span.dataset.manualHighlightId,
+      offset: Number(span.dataset.start || 0) + offset,
+    }
+  }
+
+  const range = selection.getRangeAt(0)
+  const start = offsetFromNode(range.startContainer, range.startOffset)
+  const end = offsetFromNode(range.endContainer, range.endOffset)
+  if (!start || !end || start.id !== end.id) return null
+  const ordered = start.offset <= end.offset ? { start: start.offset, end: end.offset } : { start: end.offset, end: start.offset }
+  if (ordered.end <= ordered.start) return null
+  return { id: start.id, ...ordered }
+}
+
+function ManualHighlightText({ text, textId, highlights = [], speechRange = null }) {
+  const ranges = mergeTextRanges(highlights)
+  const boundaries = new Set([0, (text || '').length])
+  ranges.forEach(range => { boundaries.add(range.start); boundaries.add(range.end) })
+  if (speechRange) { boundaries.add(speechRange.start); boundaries.add(speechRange.end) }
+  const points = [...boundaries]
+    .filter(point => point >= 0 && point <= (text || '').length)
+    .sort((a, b) => a - b)
+
+  return points.slice(0, -1).map((start, i) => {
+    const end = points[i + 1]
+    if (end <= start) return null
+    const manuallyHighlighted = ranges.some(range => start >= range.start && end <= range.end)
+    const speechHighlighted = speechRange && start >= speechRange.start && end <= speechRange.end
+    const className = [
+      'manual-highlight-segment',
+      manuallyHighlighted ? 'manual-highlight-active' : '',
+      speechHighlighted ? 'speech-highlight-active' : '',
+    ].filter(Boolean).join(' ')
+    return (
+      <span key={`${start}-${end}`} className={className} data-manual-highlight-id={textId} data-start={start}>
+        {text.slice(start, end)}
+      </span>
+    )
+  })
+}
+
 function splitSpeechChunks(text, maxWords) {
  const words = (text || '').trim().split(/\s+/).filter(Boolean)
  if (!words.length) return []
@ -53,20 +144,6 @@ function buildQuestionSpeechText(question, index) {
  return segments.map(s => s.text).join(' ')
 }

-function HighlightedSpeechText({ text, activeChunk, maxWords }) {
-  const chunks = splitSpeechChunks(text, maxWords)
-  return chunks.map((chunk, i) => (
-    <span key={i} style={{
-      background: activeChunk === i ? '#fef08a' : 'transparent',
-      borderRadius: 4,
-      padding: activeChunk === i ? '1px 3px' : 0,
-      transition: 'background 0.15s ease',
-    }}>
-      {chunk}{i < chunks.length - 1 ? ' ' : ''}
-    </span>
-  ))
-}
-
 function getActiveSpeechSegment(audio, segments) {
  if (!segments.length) return null
  if (!audio || !Number.isFinite(audio.duration) || audio.duration <= 0) return 0
@ -296,6 +373,7 @@ export default function QuizPage() {
  const [startedAt, setStartedAt] = useState(null)
  const [favorites, setFavorites] = useState([])
  const [activeReadSegment, setActiveReadSegment] = useState(null)
+  const [manualHighlights, setManualHighlights] = useState({})
  const timerRef = useRef(null)
  const toastRef = useRef(null)
  const hasStarted = useRef(false)
@ -308,6 +386,21 @@ export default function QuizPage() {
    toastRef.current = setTimeout(() => setToast(''), 3000)
  }

+  useEffect(() => {
+    try {
+      const saved = localStorage.getItem(`quiz-highlights:${id}`)
+      setManualHighlights(saved ? JSON.parse(saved) : {})
+    } catch {
+      setManualHighlights({})
+    }
+  }, [id])
+
+  useEffect(() => {
+    try {
+      localStorage.setItem(`quiz-highlights:${id}`, JSON.stringify(manualHighlights))
+    } catch { }
+  }, [id, manualHighlights])
+
  const [leaveTarget, setLeaveTarget] = useState(null)
  const questions = quiz?.questions || []
  const current = questions[currentIdx]
@ -359,7 +452,7 @@ export default function QuizPage() {
    }
  }, [quizMode, questions, currentIdx, selectedVoice, voices.length, fetchTtsAudio])

-  const resumeQuiz = useCallback(async (saved) => {
+  const resumeQuiz = useCallback(async (saved, availableVoices = []) => {
    const savedMode = saved.mode || saved.quizMode
    const mode = savedMode === 'exam' ? 'exam' : 'study'
    const savedIdx = saved.current_idx ?? saved.currentIdx ?? 0
@ -393,7 +486,7 @@ export default function QuizPage() {
    setAnswers(savedAnswers)
    setCurrentIdx(savedIdx)
    setAttemptId(saved.attempt_id || saved.attemptId)
-    if (saved.voice) setSelectedVoice(saved.voice)
+    if (saved.voice && availableVoices.some(v => v.id === saved.voice)) setSelectedVoice(saved.voice)
    if (saved.started_at) setStartedAt(saved.started_at)
    // Restore timer — calculate remaining from started_at + total_time
    if (saved.total_time && saved.started_at) {
@ -436,7 +529,7 @@ export default function QuizPage() {
            headers: { 'x-quiz-session': SESSION_ID },
          })
          if (progressRes.data) {
-            await resumeQuiz(progressRes.data)
+            await resumeQuiz(progressRes.data, voicesRes.data)
          }
        } catch (err) {
          if (err.response?.status === 409) {
@ -516,10 +609,50 @@ const timerStarted = timeLeft !== null
      }, { headers: { 'x-quiz-session': SESSION_ID } }).catch(() => {})
    }, 1500) // debounce 1.5s
    return () => clearTimeout(saveProgressRef.current)
-  }, [answers, currentIdx, attemptId, timeLeft, startedAt, totalTime])
+  }, [answers, currentIdx, attemptId, quizMode, selectedVoice, timeLeft, startedAt, totalTime])

  const setAnswer = (questionId, value) => setAnswers(prev => ({ ...prev, [questionId]: value }))

+  const updateManualHighlights = (action) => {
+    if (!current) return
+    const selected = getManualHighlightSelection()
+    if (!selected) {
+      showToast('Select question or option text first')
+      return
+    }
+    const [questionKey, fieldKey] = selected.id.split('::')
+    if (questionKey !== String(current.id)) {
+      showToast('Select text from the current question')
+      return
+    }
+    setManualHighlights(prev => {
+      const questionRanges = prev[current.id] || {}
+      const existing = questionRanges[fieldKey] || []
+      const nextRanges = action === 'remove'
+        ? removeTextRange(existing, selected)
+        : mergeTextRanges([...existing, { start: selected.start, end: selected.end }])
+      const nextQuestion = { ...questionRanges, [fieldKey]: nextRanges }
+      if (!nextRanges.length) delete nextQuestion[fieldKey]
+      return { ...prev, [current.id]: nextQuestion }
+    })
+    window.getSelection?.().removeAllRanges()
+    showToast(action === 'remove' ? 'Highlight removed' : 'Highlighted')
+  }
+
+  const clearCurrentHighlights = () => {
+    if (!current || !manualHighlights[current.id]) return
+    setManualHighlights(prev => {
+      const next = { ...prev }
+      delete next[current.id]
+      return next
+    })
+    showToast('Question highlights cleared')
+  }
+
+  const highlightsFor = (fieldKey) => manualHighlights[current?.id]?.[fieldKey] || []
+
+  const hasActiveTextSelection = () => Boolean(window.getSelection?.().toString().trim())
+
  const safeNavigate = (targetIdx, { keepReadThrough = false } = {}) => {
    if (!keepReadThrough) setReadThrough(false)
    setCurrentIdx(targetIdx)
@ -577,7 +710,34 @@ const timerStarted = timeLeft !== null
  const answeredCount = Object.keys(answers).length
  const totalCount = questions.length
  const isLast = currentIdx === totalCount - 1
+  const quizNavigation = (position = 'bottom') => (
+    <div className={`quiz-nav-controls quiz-nav-controls-${position}`}>
+      <button className="btn btn-secondary"
+        onClick={() => safeNavigate(Math.max(0, currentIdx - 1))}
+        disabled={currentIdx === 0}>← Prev</button>
+
+      <button className="quiz-nav-toggle btn btn-secondary btn-sm"
+        onClick={() => setNavOpen(v => !v)}>
+        {currentIdx + 1} / {totalCount} {navOpen ? '▼' : '▲'}
+      </button>
+
+      {isLast ? (
+        <button className="btn btn-primary" onClick={() => handleSubmit(false)} disabled={submitting}>
+          {submitting ? 'Submitting...' : 'Submit Quiz'}
+        </button>
+      ) : (
+        <button className="btn btn-primary" onClick={() => safeNavigate(Math.min(totalCount - 1, currentIdx + 1))}>Next →</button>
+      )}
+    </div>
+  )
  const activeReadForCurrent = current && activeReadSegment?.questionId === current.id
+  const questionSpeechRange = current
+    ? getSpeechChunkRange(
+      questionStem(current),
+      QUESTION_HIGHLIGHT_WORDS,
+      activeReadForCurrent && activeReadSegment.type === 'question' ? activeReadSegment.chunkIndex : null,
+    )
+    : null

  const toggleFavorite = async (questionId) => {
    const isFavorited = favorites.includes(questionId)
@ -670,10 +830,10 @@ const timerStarted = timeLeft !== null
      )}

      {/* Header */}
-      <div className="card" style={{ marginBottom: 14 }}>
+      <div className="card quiz-header-card" style={{ marginBottom: 14 }}>
        <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', flexWrap: 'wrap', gap: 8 }}>
          <div>
-            <h2 style={{ marginBottom: 2, fontSize: '1rem' }}>{quiz.title}</h2>
+            <h2 className="quiz-header-title">{quiz.title}</h2>
            <div style={{ fontSize: '0.82rem', color: 'var(--text-muted)', display: 'flex', gap: 8, alignItems: 'center', flexWrap: 'wrap' }}>
              <span style={{
                background: isStudy ? '#d1fae5' : '#e0e7ff',
@ -710,22 +870,25 @@ const timerStarted = timeLeft !== null
        <div className="fill" style={{ width: `${((currentIdx + 1) / totalCount) * 100}%` }} />
      </div>

+      {quizNavigation('top')}
+
      {/* Two-column layout: content + desktop sidebar */}
      <div className="quiz-layout">
        {/* Main content */}
        <div style={{ flex: 1, minWidth: 0 }}>
          {current && (
            <div className="question-card" style={{
-              boxShadow: activeReadForCurrent ? '0 0 0 3px rgba(250, 204, 21, 0.28)' : undefined,
-              borderColor: activeReadForCurrent ? '#facc15' : undefined,
+              boxShadow: activeReadForCurrent ? '0 0 0 3px rgba(59, 130, 246, 0.22)' : undefined,
+              borderColor: activeReadForCurrent ? '#60a5fa' : undefined,
            }}>
              <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'flex-start', marginBottom: 8, gap: 12 }}>
                <h3 style={{ marginBottom: 0, flex: 1 }}>
                  Q{currentIdx + 1}.{' '}
-                  <HighlightedSpeechText
+                  <ManualHighlightText
                    text={questionStem(current)}
-                    maxWords={QUESTION_HIGHLIGHT_WORDS}
-                    activeChunk={activeReadForCurrent && activeReadSegment.type === 'question' ? activeReadSegment.chunkIndex : null}
+                    textId={`${current.id}::question`}
+                    highlights={highlightsFor('question')}
+                    speechRange={questionSpeechRange}
                  />
                </h3>
                <button
@ -778,11 +941,17 @@ const timerStarted = timeLeft !== null
                    {readThrough ? 'Stop listen-through' : 'Listen through'}
                  </button>
                )}
-                {voices.length > 0 && (
-                  <span style={{ fontSize: '0.75rem', color: 'var(--text-muted)' }}>
-                    Preloading next {Math.min(TTS_PRELOAD_AHEAD, Math.max(totalCount - currentIdx - 1, 0))} question{Math.min(TTS_PRELOAD_AHEAD, Math.max(totalCount - currentIdx - 1, 0)) === 1 ? '' : 's'}
-                  </span>
-                )}
+                <div className="manual-highlight-toolbar" aria-label="Question highlight tools">
+                  <button className="btn btn-secondary btn-sm" onClick={() => updateManualHighlights('add')} title="Highlight selected text">
+                    Highlight
+                  </button>
+                  <button className="btn btn-secondary btn-sm" onClick={() => updateManualHighlights('remove')} title="Remove highlight from selected text">
+                    Remove highlight
+                  </button>
+                  <button className="btn btn-secondary btn-sm" onClick={clearCurrentHighlights} disabled={!manualHighlights[current.id]} title="Clear all highlights on this question">
+                    Clear
+                  </button>
+                </div>
              </div>
              <span className="badge" style={{ background: '#e0e7ff', color: '#3730a3', margin: '6px 0 12px', display: 'inline-block' }}>
                {current.question_type === 'mcq' ? 'Multiple Choice' : current.question_type === 'true_false' ? 'True / False' : 'Fill in the Blank'}
@ -806,19 +975,26 @@ const timerStarted = timeLeft !== null
                    const activeOptionChunk = activeReadForCurrent && activeReadSegment.type === 'option' && activeReadSegment.index === i
                      ? activeReadSegment.chunkIndex
                      : null
+                    const optionSpeechRange = getSpeechChunkRange(opt, OPTION_HIGHLIGHT_WORDS, activeOptionChunk)
+                    const optionFieldKey = `option-${i}`
                    return (
                      <div key={i}
                        className={`option ${isSelected && !hasAnswered ? 'selected' : ''} ${showCorrect ? 'correct' : ''} ${showWrong ? 'incorrect' : ''}`}
-                        onClick={() => !hasAnswered && setAnswer(current.id, opt)}
+                        onClick={() => !hasAnswered && !hasActiveTextSelection() && setAnswer(current.id, opt)}
                        style={{
                          cursor: hasAnswered ? 'default' : 'pointer',
-                          borderColor: activeOptionChunk !== null ? '#facc15' : undefined,
-                          boxShadow: activeOptionChunk !== null ? '0 0 0 3px rgba(250, 204, 21, 0.25)' : undefined,
+                          borderColor: activeOptionChunk !== null ? '#60a5fa' : undefined,
+                          boxShadow: activeOptionChunk !== null ? '0 0 0 3px rgba(59, 130, 246, 0.2)' : undefined,
                          transition: 'background 0.15s ease, box-shadow 0.15s ease',
                        }}>
                        <span className="option-letter">{letter}</span>
                        <span style={{ flex: 1 }}>
-                          <HighlightedSpeechText text={opt} maxWords={OPTION_HIGHLIGHT_WORDS} activeChunk={activeOptionChunk} />
+                          <ManualHighlightText
+                            text={opt}
+                            textId={`${current.id}::${optionFieldKey}`}
+                            highlights={highlightsFor(optionFieldKey)}
+                            speechRange={optionSpeechRange}
+                          />
                        </span>
                        {showCorrect && <span style={{ marginLeft: 'auto', fontSize: '0.8rem', fontWeight: 700, color: 'var(--correct-fg)' }}>✓ Correct</span>}
                        {showWrong && <span style={{ marginLeft: 'auto', fontSize: '0.8rem', fontWeight: 700, color: 'var(--wrong-fg)' }}>✗ Wrong</span>}
@ -849,26 +1025,7 @@ const timerStarted = timeLeft !== null
            </div>
          )}

-          {/* Prev / Next + mobile nav toggle */}
-          <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', marginTop: 14, gap: 8 }}>
-            <button className="btn btn-secondary"
-              onClick={() => safeNavigate(Math.max(0, currentIdx - 1))}
-              disabled={currentIdx === 0}>← Prev</button>
-
-            {/* Mobile-only nav toggle */}
-            <button className="quiz-nav-toggle btn btn-secondary btn-sm"
-              onClick={() => setNavOpen(v => !v)}>
-              {currentIdx + 1} / {totalCount} {navOpen ? '▼' : '▲'}
-            </button>
-
-            {isLast ? (
-              <button className="btn btn-primary" onClick={() => handleSubmit(false)} disabled={submitting}>
-                {submitting ? 'Submitting...' : 'Submit Quiz'}
-              </button>
-            ) : (
-            <button className="btn btn-primary" onClick={() => safeNavigate(Math.min(totalCount - 1, currentIdx + 1))}>Next →</button>
-            )}
-          </div>
+          {quizNavigation('bottom')}

          {/* Mobile: collapsible number grid */}
          {navOpen && (
--- a/mobile/android/app/build.gradle
+++ b/mobile/android/app/build.gradle
@ -3,6 +3,12 @@ apply plugin: 'com.android.application'
 android {
    namespace "com.pedshub.quiz"
    compileSdk rootProject.ext.compileSdkVersion
+    def releaseKeystoreFile = System.getenv("ANDROID_KEYSTORE_FILE")
+    def releaseKeystorePassword = System.getenv("ANDROID_KEYSTORE_PASSWORD")
+    def releaseKeyAlias = System.getenv("ANDROID_KEY_ALIAS")
+    def releaseKeyPassword = System.getenv("ANDROID_KEY_PASSWORD")
+    def hasReleaseSigning = releaseKeystoreFile && releaseKeystorePassword && releaseKeyAlias && releaseKeyPassword
+
    defaultConfig {
        applicationId "com.pedshub.quiz"
        minSdkVersion rootProject.ext.minSdkVersion
@ -13,12 +19,25 @@ android {
        aaptOptions {
             // Files and dirs to omit from the packaged assets dir, modified to accommodate modern web apps.
             // Default: https://android.googlesource.com/platform/frameworks/base/+/282e181b58cf72b6ca770dc7ca5f91f135444502/tools/aapt/AaptAssets.cpp#61
-            ignoreAssetsPattern '!.svn:!.git:!.ds_store:!*.scc:.*:!CVS:!thumbs.db:!picasa.ini:!*~'
+             ignoreAssetsPattern '!.svn:!.git:!.ds_store:!*.scc:.*:!CVS:!thumbs.db:!picasa.ini:!*~'
+        }
+    }
+    signingConfigs {
+        release {
+            if (hasReleaseSigning) {
+                storeFile file(releaseKeystoreFile)
+                storePassword releaseKeystorePassword
+                keyAlias releaseKeyAlias
+                keyPassword releaseKeyPassword
+            }
        }
    }
    buildTypes {
        release {
            minifyEnabled false
+            if (hasReleaseSigning) {
+                signingConfig signingConfigs.release
+            }
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
--- a/mobile/android/app/src/main/assets/capacitor.config.json
+++ b/mobile/android/app/src/main/assets/capacitor.config.json
@ -20,9 +20,9 @@
 		}
 	},
 	"android": {
-		"allowMixedContent": true,
+		"allowMixedContent": false,
 		"backgroundColor": "#0f172a",
-		"webContentsDebuggingEnabled": true,
+		"webContentsDebuggingEnabled": false,
 		"androidScheme": "https"
 	},
 	"ios": {
--- a/mobile/android/app/src/main/assets/public/index.html
+++ b/mobile/android/app/src/main/assets/public/index.html
@ -21,7 +21,7 @@

      <div class="form-group">
        <label>Server URL</label>
-        <input type="url" id="server-url" placeholder="https://pedshub.com" autocapitalize="none" autocorrect="off" spellcheck="false">
+        <input type="url" id="server-url" placeholder="https://quiz.danvics.com" autocapitalize="none" autocorrect="off" spellcheck="false">
      </div>

      <button id="btn-connect" class="btn-primary">Connect</button>
--- a/mobile/android/app/src/main/assets/public/launcher.js
+++ b/mobile/android/app/src/main/assets/public/launcher.js
@ -1,6 +1,6 @@
 (function() {
  var STORAGE_KEY = 'pedshub_server_url';
-  var DEFAULT_URL = 'https://pedshub.com';
+  var DEFAULT_URL = 'https://quiz.danvics.com';

  var setupScreen = document.getElementById('setup-screen');
  var connectingScreen = document.getElementById('connecting-screen');
--- a/mobile/capacitor.config.json
+++ b/mobile/capacitor.config.json
@ -18,9 +18,9 @@
    }
  },
  "android": {
-    "allowMixedContent": true,
+    "allowMixedContent": false,
    "backgroundColor": "#0f172a",
-    "webContentsDebuggingEnabled": true,
+    "webContentsDebuggingEnabled": false,
    "androidScheme": "https"
  },
  "ios": {
--- a/mobile/ios/App/App/capacitor.config.json
+++ b/mobile/ios/App/App/capacitor.config.json
@ -20,9 +20,9 @@
 		}
 	},
 	"android": {
-		"allowMixedContent": true,
+		"allowMixedContent": false,
 		"backgroundColor": "#0f172a",
-		"webContentsDebuggingEnabled": true,
+		"webContentsDebuggingEnabled": false,
 		"androidScheme": "https"
 	},
 	"ios": {
--- a/mobile/ios/App/App/public/index.html
+++ b/mobile/ios/App/App/public/index.html
@ -21,7 +21,7 @@

      <div class="form-group">
        <label>Server URL</label>
-        <input type="url" id="server-url" placeholder="https://pedshub.com" autocapitalize="none" autocorrect="off" spellcheck="false">
+        <input type="url" id="server-url" placeholder="https://quiz.danvics.com" autocapitalize="none" autocorrect="off" spellcheck="false">
      </div>

      <button id="btn-connect" class="btn-primary">Connect</button>
--- a/mobile/ios/App/App/public/launcher.js
+++ b/mobile/ios/App/App/public/launcher.js
@ -1,6 +1,6 @@
 (function() {
  var STORAGE_KEY = 'pedshub_server_url';
-  var DEFAULT_URL = 'https://pedshub.com';
+  var DEFAULT_URL = 'https://quiz.danvics.com';

  var setupScreen = document.getElementById('setup-screen');
  var connectingScreen = document.getElementById('connecting-screen');
--- a/mobile/package.json
+++ b/mobile/package.json
@ -7,7 +7,9 @@
    "sync": "npx cap sync",
    "android": "npx cap open android",
    "ios": "npx cap open ios",
-    "build:android": "npx cap sync android && cd android && ./gradlew assembleRelease"
+    "build:android": "npx cap sync android && cd android && ./gradlew assembleRelease",
+    "build:android:release": "npx cap sync android && cd android && ./gradlew assembleRelease",
+    "build:android:debug": "npx cap sync android && cd android && ./gradlew assembleDebug"
  },
  "dependencies": {
    "@capacitor/android": "^6.0.0",
--- a/mobile/src/index.html
+++ b/mobile/src/index.html
@ -21,7 +21,7 @@

      <div class="form-group">
        <label>Server URL</label>
-        <input type="url" id="server-url" placeholder="https://pedshub.com" autocapitalize="none" autocorrect="off" spellcheck="false">
+        <input type="url" id="server-url" placeholder="https://quiz.danvics.com" autocapitalize="none" autocorrect="off" spellcheck="false">
      </div>

      <button id="btn-connect" class="btn-primary">Connect</button>
--- a/mobile/src/launcher.js
+++ b/mobile/src/launcher.js
@ -1,6 +1,6 @@
 (function() {
  var STORAGE_KEY = 'pedshub_server_url';
-  var DEFAULT_URL = 'https://pedshub.com';
+  var DEFAULT_URL = 'https://quiz.danvics.com';

  var setupScreen = document.getElementById('setup-screen');
  var connectingScreen = document.getElementById('connecting-screen');