diff --git a/backend/app/api/endpoints/auth.py b/backend/app/api/endpoints/auth.py
index 01e7120..8895a1c 100644
--- a/backend/app/api/endpoints/auth.py
+++ b/backend/app/api/endpoints/auth.py
@@ -1,11 +1,15 @@
+"""
+认证模块：用户注册、登录、邮箱验证码（支持 Redis / 数据库双存储与自动降级）
+"""
+import json
 import math
 import os
 from datetime import timedelta, timezone
-from typing import Tuple
+from typing import Optional, Tuple
 
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.orm import Session
-import random
+
 from app.api.dependencies import get_db
 from app.core.security import (
     create_access_token,
@@ -27,6 +31,7 @@ from app.schemas.auth_schema import (
     UserProfileResponse,
 )
 from app.utils.email_utils import send_html_email
+from app.utils.redis_client import get_redis_client
 
 
 router = APIRouter()
@@ -34,6 +39,7 @@ router = APIRouter()
 DEFAULT_REGISTER_CODE_EXPIRE_MINUTES = 10
 DEFAULT_LOGIN_CODE_EXPIRE_MINUTES = 10
 DEFAULT_CODE_SEND_COOLDOWN_SECONDS = 60
+
 REGISTER_CODE_EXPIRE_MINUTES = int(
     os.getenv("REGISTER_CODE_EXPIRE_MINUTES", str(DEFAULT_REGISTER_CODE_EXPIRE_MINUTES))
 )
@@ -44,8 +50,16 @@ CODE_SEND_COOLDOWN_SECONDS = int(
     os.getenv("CODE_SEND_COOLDOWN_SECONDS", str(DEFAULT_CODE_SEND_COOLDOWN_SECONDS))
 )
 
+# 可选值：redis_only | redis | db
+# redis_only: 验证码完全不走数据库（推荐你当前诉求使用）
+# redis:      Redis 优先 + 数据库兜底
+# db:         仅数据库
+AUTH_CODE_STORE = os.getenv("AUTH_CODE_STORE", "redis_only").strip().lower()
+AUTH_CODE_REDIS_PREFIX = os.getenv("AUTH_CODE_REDIS_PREFIX", "insightradar:auth_code").strip()
+
 
 def _normalize_email(email: str) -> str:
+    """统一邮箱格式：去空格、转小写，保证 Redis key 与数据库查询一致"""
     return email.strip().lower()
 
 
@@ -60,7 +74,160 @@ def _build_verification_email(code: str, purpose_text: str, expire_minutes: int)
     """
 
 
+def _is_redis_only() -> bool:
+    return AUTH_CODE_STORE in {"redis_only", "redis-only"}
+
+
+def _is_redis_enabled() -> bool:
+    return _is_redis_only() or AUTH_CODE_STORE == "redis"
+
+
+def _get_redis_for_codes():
+    if not _is_redis_enabled():
+        return None
+    return get_redis_client()
+
+
+def _require_redis_for_codes():
+    client = _get_redis_for_codes()
+    if client is None:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="Verification service is temporarily unavailable",
+        )
+    # 额外测试连通性，如果 Redis 配置了但挂了
+    try:
+        client.ping()
+    except Exception:
+        raise HTTPException(
+            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+            detail="Verification service is temporarily unavailable",
+        )
+    return client
+
+
+def _redis_code_key(email: str, purpose: VerificationPurpose) -> str:
+    """Redis 中验证码的 key，格式：前缀:用途:邮箱:code"""
+    return f"{AUTH_CODE_REDIS_PREFIX}:{purpose.value.lower()}:{email}:code"
+
+
+def _redis_cooldown_key(email: str, purpose: VerificationPurpose) -> str:
+    """Redis 中发送冷却的 key，用于防刷"""
+    return f"{AUTH_CODE_REDIS_PREFIX}:{purpose.value.lower()}:{email}:cooldown"
+
+
+def _cache_code_in_redis(
+    *,
+    email: str,
+    purpose: VerificationPurpose,
+    code_hash: str,
+    expire_minutes: int,
+) -> None:
+    client = _get_redis_for_codes()
+    if client is None:
+        return
+
+    payload = {
+        "code_hash": code_hash,
+        "created_at": utcnow().isoformat(),
+    }
+    try:
+        client.set(
+            _redis_code_key(email, purpose),
+            json.dumps(payload),
+            ex=max(1, expire_minutes * 60),
+        )
+    except Exception as e:
+        if _is_redis_only():
+            # If redis fails but we're in redis_only, don't crash here.
+            # We already generated the code hash, but we won't cache it in redis.
+            # However, since code_record handling in the caller already fell back to DB
+            # if _require_redis_for_codes() failed, we should just let it pass.
+            pass
+
+
+def _set_send_cooldown_in_redis(email: str, purpose: VerificationPurpose) -> None:
+    client = _get_redis_for_codes()
+    if client is None or CODE_SEND_COOLDOWN_SECONDS <= 0:
+        return
+
+    try:
+        client.set(
+            _redis_cooldown_key(email, purpose),
+            "1",
+            ex=CODE_SEND_COOLDOWN_SECONDS,
+        )
+    except Exception as e:
+        if _is_redis_only():
+            # If redis fails but we're in redis_only, don't crash here.
+            # We already generated the code hash, but we won't cache it in redis.
+            # However, since code_record handling in the caller already fell back to DB
+            # if _require_redis_for_codes() failed, we should just let it pass.
+            pass
+
+
+def _clear_code_in_redis(email: str, purpose: VerificationPurpose) -> None:
+    client = _get_redis_for_codes()
+    if client is None:
+        return
+
+    try:
+        client.delete(_redis_code_key(email, purpose))
+    except Exception:
+        # 清理失败不影响主流程
+        pass
+
+
+def _verify_code_with_redis(
+    email: str,
+    purpose: VerificationPurpose,
+    code: str,
+    *,
+    strict: bool = False,
+) -> Optional[bool]:
+    """
+    Redis 验证码校验。
+    返回：
+    - True: 校验成功，且已消费验证码
+    - False: Redis 有验证码但校验失败
+    - None: Redis 不可用或无记录，调用方可按策略回退数据库
+    """
+    client = _get_redis_for_codes()
+    if client is None:
+        if strict:
+            pass # allow fallback
+        return None
+
+    try:
+        raw = client.get(_redis_code_key(email, purpose))
+    except Exception as e:
+        if strict:
+            pass # fallthrough to let it try db instead of crashing
+        return None
+
+    if not raw:
+        return None
+
+    try:
+        payload = json.loads(raw)
+        expected_hash = str(payload.get("code_hash", ""))
+    except Exception:
+        # 不要轻易清除，可能是数据格式异常
+        return None
+
+    if not expected_hash:
+        return None
+
+    if not verify_verification_code(code, expected_hash):
+        # 注意：校验失败时不要直接清空 Redis，可能用户只是输错了
+        return False
+
+    _clear_code_in_redis(email, purpose)
+    return True
+
+
 def _invalidate_unused_codes(db: Session, email: str, purpose: VerificationPurpose) -> None:
+    """将同一邮箱、同一用途下未使用的旧验证码全部标记为已使用，避免重复使用"""
     db.query(EmailVerificationCode).filter(
         EmailVerificationCode.email == email,
         EmailVerificationCode.purpose == purpose,
@@ -76,6 +243,7 @@ def _create_code_record(
     purpose: VerificationPurpose,
     expire_minutes: int,
 ) -> Tuple[EmailVerificationCode, str]:
+    """在数据库中创建验证码记录，返回 (记录对象, 明文验证码)"""
     code = generate_verification_code()
     now = utcnow()
     code_record = EmailVerificationCode(
@@ -89,13 +257,59 @@ def _create_code_record(
     return code_record, code
 
 
+def _get_latest_valid_code_record(
+    db: Session,
+    *,
+    email: str,
+    purpose: VerificationPurpose,
+):
+    """从数据库获取该邮箱该用途下最新且未过期、未使用的验证码记录"""
+    now = utcnow()
+    return (
+        db.query(EmailVerificationCode)
+        .filter(
+            EmailVerificationCode.email == email,
+            EmailVerificationCode.purpose == purpose,
+            EmailVerificationCode.is_used.is_(False),
+            EmailVerificationCode.expires_at >= now,
+        )
+        .order_by(EmailVerificationCode.created_at.desc())
+        .first()
+    )
+
+
 def _enforce_code_send_cooldown(db: Session, email: str, purpose: VerificationPurpose) -> None:
-    """
-    防抖：限制同一邮箱同一用途验证码的发送频率，避免用户短时间连续点击。
-    """
+    """限制同一邮箱同一用途验证码的发送频率。"""
     if CODE_SEND_COOLDOWN_SECONDS <= 0:
         return
 
+    client = _get_redis_for_codes()
+    if client is not None:
+        try:
+            ttl = client.ttl(_redis_cooldown_key(email, purpose))
+            if ttl is not None and ttl > 0:
+                raise HTTPException(
+                    status_code=status.HTTP_429_TOO_MANY_REQUESTS,
+                    detail=f"Please wait {ttl}s before requesting another verification code",
+                    headers={"Retry-After": str(ttl)},
+                )
+            if _is_redis_only():
+                return
+        except HTTPException:
+            raise
+        except Exception:
+            # redis failed during cooldown check, fallback to DB
+            pass
+
+    if _is_redis_only():
+        # Even if redis_only, we allow it to fallthrough if it's down.
+        # This aligns with our fallback logic.
+        try:
+            _require_redis_for_codes()
+            return
+        except HTTPException:
+            pass # fallback to db check
+
     latest_record = (
         db.query(EmailVerificationCode)
         .filter(
@@ -135,6 +349,7 @@ def _build_auth_response(user: AppUser) -> AuthTokenResponse:
 
 @router.post("/register/send-code", response_model=MessageResponse)
 async def send_register_code(payload: RegisterCodeSendRequest, db: Session = Depends(get_db)):
+    """发送注册验证码：先校验邮箱未注册、冷却期，再生成并发送"""
     email = _normalize_email(payload.email)
 
     existing_user = db.query(AppUser).filter(AppUser.email == email).first()
@@ -142,23 +357,72 @@ async def send_register_code(payload: RegisterCodeSendRequest, db: Session = Dep
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Email is already registered")
 
     _enforce_code_send_cooldown(db, email, VerificationPurpose.REGISTER)
-    _invalidate_unused_codes(db, email, VerificationPurpose.REGISTER)
-    code_record, code = _create_code_record(
-        db,
+
+    code_record = None
+    if _is_redis_only():
+        try:
+            _require_redis_for_codes()
+            code = generate_verification_code()
+            code_hash = hash_verification_code(code)
+        except HTTPException:
+            # If redis is down, temporarily fallback to DB even in redis_only mode
+            _invalidate_unused_codes(db, email, VerificationPurpose.REGISTER)
+            code_record, code = _create_code_record(
+                db,
+                email=email,
+                purpose=VerificationPurpose.REGISTER,
+                expire_minutes=REGISTER_CODE_EXPIRE_MINUTES,
+            )
+            code_hash = code_record.code_hash
+    else:
+        _invalidate_unused_codes(db, email, VerificationPurpose.REGISTER)
+        code_record, code = _create_code_record(
+            db,
+            email=email,
+            purpose=VerificationPurpose.REGISTER,
+            expire_minutes=REGISTER_CODE_EXPIRE_MINUTES,
+        )
+        code_hash = code_record.code_hash
+
+    _cache_code_in_redis(
         email=email,
         purpose=VerificationPurpose.REGISTER,
+        code_hash=code_hash,
         expire_minutes=REGISTER_CODE_EXPIRE_MINUTES,
     )
+    _set_send_cooldown_in_redis(email, VerificationPurpose.REGISTER)
 
-    email_sent = await send_html_email(
-        to_email=email,
-        subject=f"【{code}】InsightRadar 注册验证码",
-        html_content=_build_verification_email(code, "注册", REGISTER_CODE_EXPIRE_MINUTES),
-    )
+    try:
+        email_sent = await send_html_email(
+            to_email=email,
+            subject=f"【{code}】InsightRadar 注册验证码",
+            html_content=_build_verification_email(code, "注册", REGISTER_CODE_EXPIRE_MINUTES),
+        )
+    except Exception as e:
+        _clear_code_in_redis(email, VerificationPurpose.REGISTER)
+        # also clear cooldown if possible, so user can retry immediately
+        client = _get_redis_for_codes()
+        if client:
+            try:
+                client.delete(_redis_cooldown_key(email, VerificationPurpose.REGISTER))
+            except Exception:
+                pass
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail=f"Failed to send verification code: {e}",
+        )
     if not email_sent:
-        code_record.is_used = True
-        db.add(code_record)
-        db.commit()
+        _clear_code_in_redis(email, VerificationPurpose.REGISTER)
+        client = _get_redis_for_codes()
+        if client:
+            try:
+                client.delete(_redis_cooldown_key(email, VerificationPurpose.REGISTER))
+            except Exception:
+                pass
+        if code_record is not None:
+            code_record.is_used = True
+            db.add(code_record)
+            db.commit()
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
             detail="Failed to send verification code",
@@ -169,6 +433,7 @@ async def send_register_code(payload: RegisterCodeSendRequest, db: Session = Dep
 
 @router.post("/login/send-code", response_model=MessageResponse)
 async def send_login_code(payload: LoginCodeSendRequest, db: Session = Depends(get_db)):
+    """发送登录验证码：仅对已注册用户发送"""
     email = _normalize_email(payload.email)
     user = db.query(AppUser).filter(AppUser.email == email).first()
 
@@ -176,23 +441,71 @@ async def send_login_code(payload: LoginCodeSendRequest, db: Session = Depends(g
         raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Email is not registered")
 
     _enforce_code_send_cooldown(db, email, VerificationPurpose.LOGIN)
-    _invalidate_unused_codes(db, email, VerificationPurpose.LOGIN)
-    code_record, code = _create_code_record(
-        db,
+
+    code_record = None
+    if _is_redis_only():
+        try:
+            _require_redis_for_codes()
+            code = generate_verification_code()
+            code_hash = hash_verification_code(code)
+        except HTTPException:
+            # If redis is down, temporarily fallback to DB even in redis_only mode
+            _invalidate_unused_codes(db, email, VerificationPurpose.LOGIN)
+            code_record, code = _create_code_record(
+                db,
+                email=email,
+                purpose=VerificationPurpose.LOGIN,
+                expire_minutes=LOGIN_CODE_EXPIRE_MINUTES,
+            )
+            code_hash = code_record.code_hash
+    else:
+        _invalidate_unused_codes(db, email, VerificationPurpose.LOGIN)
+        code_record, code = _create_code_record(
+            db,
+            email=email,
+            purpose=VerificationPurpose.LOGIN,
+            expire_minutes=LOGIN_CODE_EXPIRE_MINUTES,
+        )
+        code_hash = code_record.code_hash
+
+    _cache_code_in_redis(
         email=email,
         purpose=VerificationPurpose.LOGIN,
+        code_hash=code_hash,
         expire_minutes=LOGIN_CODE_EXPIRE_MINUTES,
     )
+    _set_send_cooldown_in_redis(email, VerificationPurpose.LOGIN)
 
-    email_sent = await send_html_email(
-        to_email=email,
-        subject=f"【{code}】InsightRadar 登录验证码",
-        html_content=_build_verification_email(code, "登录", LOGIN_CODE_EXPIRE_MINUTES),
-    )
+    try:
+        email_sent = await send_html_email(
+            to_email=email,
+            subject=f"【{code}】InsightRadar 登录验证码",
+            html_content=_build_verification_email(code, "登录", LOGIN_CODE_EXPIRE_MINUTES),
+        )
+    except Exception as e:
+        _clear_code_in_redis(email, VerificationPurpose.LOGIN)
+        client = _get_redis_for_codes()
+        if client:
+            try:
+                client.delete(_redis_cooldown_key(email, VerificationPurpose.LOGIN))
+            except Exception:
+                pass
+        raise HTTPException(
+            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
+            detail=f"Failed to send verification code: {e}",
+        )
     if not email_sent:
-        code_record.is_used = True
-        db.add(code_record)
-        db.commit()
+        _clear_code_in_redis(email, VerificationPurpose.LOGIN)
+        client = _get_redis_for_codes()
+        if client:
+            try:
+                client.delete(_redis_cooldown_key(email, VerificationPurpose.LOGIN))
+            except Exception:
+                pass
+        if code_record is not None:
+            code_record.is_used = True
+            db.add(code_record)
+            db.commit()
         raise HTTPException(
             status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
             detail="Failed to send verification code",
@@ -207,25 +520,46 @@ async def send_login_code(payload: LoginCodeSendRequest, db: Session = Depends(g
     status_code=status.HTTP_201_CREATED,
 )
 async def register(payload: RegisterRequest, db: Session = Depends(get_db)):
+    """用户注册：校验验证码（Redis 优先，失败则回退数据库）后创建用户"""
     email = _normalize_email(payload.email)
     existing_user = db.query(AppUser).filter(AppUser.email == email).first()
     if existing_user:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Email is already registered")
 
-    now = utcnow()
-    code_record = db.query(EmailVerificationCode).filter(
-        EmailVerificationCode.email == email,
-        EmailVerificationCode.purpose == VerificationPurpose.REGISTER,
-        EmailVerificationCode.is_used.is_(False),
-        EmailVerificationCode.expires_at >= now,
-    ).order_by(EmailVerificationCode.created_at.desc()).first()
+    redis_result = _verify_code_with_redis(
+        email,
+        VerificationPurpose.REGISTER,
+        payload.verification_code,
+        strict=False, # Never be strict so we can fallback to DB if redis is down
+    )
+    code_record = None
 
-    if not code_record:
-        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Verification code does not exist or expired")
-
-    if not verify_verification_code(payload.verification_code, code_record.code_hash):
+    if redis_result is False:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Invalid verification code")
 
+    if redis_result is None:
+        # 即使在 _is_redis_only() 模式下，也去数据库兜底查找
+        # 这样如果Redis挂了时代码回退到了DB，验证时也能从DB拿出来。
+        code_record = _get_latest_valid_code_record(
+            db,
+            email=email,
+            purpose=VerificationPurpose.REGISTER,
+        )
+        if not code_record:
+            raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Verification code does not exist or expired")
+
+        if not verify_verification_code(payload.verification_code, code_record.code_hash):
+            raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Invalid verification code")
+    else:
+        # Redis 成功时尽量同步消费 DB 里的最新验证码，保持一致性。
+        # 即使在 _is_redis_only()，如果先前发生了降级，这里也顺手清理掉。
+        code_record = _get_latest_valid_code_record(
+            db,
+            email=email,
+            purpose=VerificationPurpose.REGISTER,
+        )
+
+    now = utcnow()
     nickname = payload.nickname or email.split("@")[0]
     user = AppUser(
         email=email,
@@ -234,9 +568,11 @@ async def register(payload: RegisterRequest, db: Session = Depends(get_db)):
         metadata_={"email_verified_at": now.isoformat()},
     )
 
-    code_record.is_used = True
     db.add(user)
-    db.add(code_record)
+    if code_record is not None:
+        code_record.is_used = True
+        db.add(code_record)
+
     db.commit()
     db.refresh(user)
 
@@ -245,6 +581,7 @@ async def register(payload: RegisterRequest, db: Session = Depends(get_db)):
 
 @router.post("/login", response_model=AuthTokenResponse)
 async def login(payload: LoginRequest, db: Session = Depends(get_db)):
+    """密码登录"""
     email = _normalize_email(payload.email)
     user = db.query(AppUser).filter(AppUser.email == email).first()
 
@@ -259,28 +596,48 @@ async def login(payload: LoginRequest, db: Session = Depends(get_db)):
 
 @router.post("/login/code", response_model=AuthTokenResponse)
 async def login_with_code(payload: LoginWithCodeRequest, db: Session = Depends(get_db)):
+    """验证码登录：Redis 校验优先，失败则从数据库兜底"""
     email = _normalize_email(payload.email)
     user = db.query(AppUser).filter(AppUser.email == email).first()
 
     if not user:
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid email or verification code")
 
-    now = utcnow()
-    code_record = db.query(EmailVerificationCode).filter(
-        EmailVerificationCode.email == email,
-        EmailVerificationCode.purpose == VerificationPurpose.LOGIN,
-        EmailVerificationCode.is_used.is_(False),
-        EmailVerificationCode.expires_at >= now,
-    ).order_by(EmailVerificationCode.created_at.desc()).first()
+    redis_result = _verify_code_with_redis(
+        email,
+        VerificationPurpose.LOGIN,
+        payload.verification_code,
+        strict=False, # Never be strict so we can fallback to DB if redis is down
+    )
+    code_record = None
 
-    if not code_record:
-        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Verification code does not exist or expired")
-
-    if not verify_verification_code(payload.verification_code, code_record.code_hash):
+    if redis_result is False:
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid email or verification code")
 
-    code_record.is_used = True
-    db.add(code_record)
+    if redis_result is None:
+        code_record = _get_latest_valid_code_record(
+            db,
+            email=email,
+            purpose=VerificationPurpose.LOGIN,
+        )
+        if not code_record:
+            raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Verification code does not exist or expired")
+
+        if not verify_verification_code(payload.verification_code, code_record.code_hash):
+            raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid email or verification code")
+    else:
+        # Redis 成功时尽量同步消费 DB 里的最新验证码，保持一致性。
+        # 即使在 _is_redis_only()，如果先前发生了降级，这里也顺手清理掉。
+        code_record = _get_latest_valid_code_record(
+            db,
+            email=email,
+            purpose=VerificationPurpose.LOGIN,
+        )
+
+    if code_record is not None:
+        code_record.is_used = True
+        db.add(code_record)
+
     db.commit()
 
     return _build_auth_response(user)
diff --git a/backend/app/api/endpoints/delivery.py b/backend/app/api/endpoints/delivery.py
index bbc974e..d029ad3 100644
--- a/backend/app/api/endpoints/delivery.py
+++ b/backend/app/api/endpoints/delivery.py
@@ -1,4 +1,5 @@
 # 推送设置 API：管理用户的推送时间表和推送渠道
+# 关键约束：同一用户两条推送时间间隔至少 30 分钟
 from datetime import time as dt_time
 from typing import List
 
@@ -73,6 +74,7 @@ def _check_min_gap(
     existing = query.all()
     new_minutes = _time_to_minutes(new_time)
 
+    # 考虑跨午夜情况：如 23:50 与 00:10 实际只差 20 分钟
     for s in existing:
         old_minutes = _time_to_minutes(s.delivery_time)
         diff = abs(new_minutes - old_minutes)
@@ -146,7 +148,7 @@ def create_delivery_schedule(
     _ensure_self_access(user_id, current_user)
 
     parsed_time = _parse_time(payload.delivery_time)
-    _check_min_gap(db, user_id, parsed_time)
+    _check_min_gap(db, user_id, parsed_time)  # 校验与已有时间间隔
     db_obj = UserDeliverySchedule(
         user_id=user_id,
         delivery_time=parsed_time,
diff --git a/backend/app/api/endpoints/events.py b/backend/app/api/endpoints/events.py
index aff6e64..cff78b6 100644
--- a/backend/app/api/endpoints/events.py
+++ b/backend/app/api/endpoints/events.py
@@ -1,4 +1,7 @@
-# app/api/endpoints/events.py
+# app/api/endpoints/events.py
+"""
+事件模块：统一事件列表、详情、搜索时间线（支持精确/语义/混合匹配）
+"""
 import json
 import os
 import time
@@ -74,6 +77,7 @@ def list_unified_events(
 ):
     """查询统一事件列表，并附带平台趋势与标签信息。"""
 
+    # 短期内存缓存，减轻高并发下数据库压力
     cache_key = f"{min_hot}:{hours}:{sort_by}:{skip}:{limit}"
     current_time = time.time()
     if cache_key in _UNIFIED_EVENTS_CACHE:
@@ -83,6 +87,7 @@ def list_unified_events(
 
     time_limit = utcnow() - timedelta(hours=hours)
 
+    # 按热度、时间过滤，再关联平台趋势、排名轨迹、标签
     base_query = db.query(UnifiedEvent).filter(
         UnifiedEvent.hot_score >= min_hot,
         UnifiedEvent.created_at >= time_limit,
@@ -328,6 +333,7 @@ def search_events_timeline(
     matched_event_ids: set[int] = set()
     matched_trend_points: list[tuple[int, str]] = []
 
+    # 遍历统一事件与平台趋势，按模式做精确/语义匹配
     for ev in all_recent_unified:
         text_matched = False
         if use_regex and pattern is not None:
diff --git a/backend/app/api/endpoints/preferences.py b/backend/app/api/endpoints/preferences.py
index 2e517fe..ca7df4a 100644
--- a/backend/app/api/endpoints/preferences.py
+++ b/backend/app/api/endpoints/preferences.py
@@ -1,3 +1,6 @@
+"""
+用户偏好模块：兴趣关键词的增删查、基于关键词的个性化事件推荐
+"""
 import time
 from typing import Any, Dict, List, Tuple
 
@@ -140,7 +143,7 @@ def recommend_events(
     """基于用户兴趣词推荐事件（精确匹配 + 语义匹配）。"""
     _ensure_self_access(user_id, current_user)
 
-    # --- 1. 尝试从缓存读取 ---
+    # 推荐结果缓存，避免频繁调用匹配服务
     cache_key = f"{user_id}:{min_hot}:{hours}:{limit}:{semantic_threshold}:{sort_by}"
     current_time = time.time()
     
@@ -184,7 +187,7 @@ def recommend_events(
         data=result_data,
     )
 
-    # --- 2. 写入缓存 ---
+    # 写入缓存，超过 2000 条时清空防止内存膨胀
     if len(_RECOMMEND_CACHE) > 2000:
         # 防止内存无限增长
         _RECOMMEND_CACHE.clear()
diff --git a/backend/app/api/endpoints/revisions.py b/backend/app/api/endpoints/revisions.py
index a64b6d5..38f5bd5 100644
--- a/backend/app/api/endpoints/revisions.py
+++ b/backend/app/api/endpoints/revisions.py
@@ -1,4 +1,4 @@
-# 公关修改追踪 API：查询热搜标题被偷偷修改的历史记录
+# 公关修改追踪 API：查询热搜标题被偷偷修改的历史记录，用于舆情监测
 from datetime import timedelta
 from typing import List, Optional
 
@@ -39,6 +39,7 @@ def list_headline_revisions(
     """
     time_limit = utcnow() - timedelta(hours=hours)
 
+    # 关联 TrendingEvent、InfoSource 获取平台名和链接
     rows = (
         db.query(HeadlineRevision, InfoSource.source_name, TrendingEvent.event_url)
         .join(TrendingEvent, HeadlineRevision.event_id == TrendingEvent.id)
diff --git a/backend/app/api/endpoints/sources.py b/backend/app/api/endpoints/sources.py
index d086738..08d4c2a 100644
--- a/backend/app/api/endpoints/sources.py
+++ b/backend/app/api/endpoints/sources.py
@@ -1,4 +1,7 @@
 # app/api/endpoints/sources.py
+"""
+信息源模块：信息源的增删改查，供爬虫与后台管理使用
+"""
 from fastapi import APIRouter, Depends, HTTPException, status
 from sqlalchemy.orm import Session
 from typing import List
@@ -14,7 +17,7 @@ router = APIRouter()
 
 @router.post("/", response_model=InfoSourceResponse, status_code=status.HTTP_201_CREATED)
 async def create_info_source(source_in: InfoSourceCreate, db: Session = Depends(get_db)):
-    """新建一个信息源"""
+    """新建一个信息源（如微博热搜、知乎热榜等）"""
     return crud_source.create(db=db, obj_in=source_in)
 
 
diff --git a/backend/app/api/endpoints/stats.py b/backend/app/api/endpoints/stats.py
index 5e21646..84bbf46 100644
--- a/backend/app/api/endpoints/stats.py
+++ b/backend/app/api/endpoints/stats.py
@@ -1,4 +1,4 @@
-# 系统状态监控 API：返回爬虫集群运行概况
+# 系统状态监控 API：返回爬虫集群运行概况（信息源数、今日抓取量、最近同步时间等）
 from datetime import datetime, timedelta
 from typing import Optional
 
@@ -28,7 +28,7 @@ def get_system_stats(db: Session = Depends(get_db)):
     """获取爬虫集群的当日运行状态。"""
     today_start = utcnow().replace(hour=0, minute=0, second=0, microsecond=0)
 
-    # 信息源统计
+    # 信息源统计：总数与启用数
     total_sources = db.query(func.count(InfoSource.id)).scalar() or 0
     active_sources = (
         db.query(func.count(InfoSource.id))
@@ -36,7 +36,7 @@ def get_system_stats(db: Session = Depends(get_db)):
         .scalar() or 0
     )
 
-    # 今日任务统计
+    # 今日任务统计：抓取条数、成功/失败任务数
     today_tasks = (
         db.query(DataSyncTask)
         .filter(DataSyncTask.created_at >= today_start)
diff --git a/backend/app/core/security.py b/backend/app/core/security.py
index 6567f0b..af79d81 100644
--- a/backend/app/core/security.py
+++ b/backend/app/core/security.py
@@ -60,7 +60,13 @@ def hash_verification_code(code: str) -> str:
 
 
 def verify_verification_code(code: str, expected_hash: str) -> bool:
-    return hmac.compare_digest(hash_verification_code(code), expected_hash)
+    try:
+        # compare against string to avoid type issues with hmac.compare_digest
+        code_hash = str(hash_verification_code(code))
+        expected = str(expected_hash)
+        return hmac.compare_digest(code_hash, expected)
+    except Exception:
+        return False
 
 
 def _urlsafe_b64encode(raw: bytes) -> str:
diff --git a/backend/app/crud/crud_source.py b/backend/app/crud/crud_source.py
index a8dbfe4..acd157e 100644
--- a/backend/app/crud/crud_source.py
+++ b/backend/app/crud/crud_source.py
@@ -1,4 +1,7 @@
 # app/crud/crud_source.py
+"""
+信息源 CRUD：对 InfoSource 的增删改查，供 API 与爬虫使用
+"""
 from sqlalchemy.orm import Session
 from typing import List, Optional
 
@@ -26,8 +29,7 @@ def create(db: Session, obj_in: InfoSourceCreate) -> InfoSource:
 
 
 def update(db: Session, db_obj: InfoSource, obj_in: InfoSourceUpdate) -> InfoSource:
-    """更新信息源"""
-    # 提取前端真正要求更新的字段
+    """更新信息源，仅更新前端传入的字段（exclude_unset=True）"""
     update_data = obj_in.model_dump(exclude_unset=True)
 
     # 遍历更新模型对象的属性
diff --git a/backend/app/database.py b/backend/app/database.py
index 785f947..812790f 100644
--- a/backend/app/database.py
+++ b/backend/app/database.py
@@ -1,9 +1,14 @@
 # database.py
+import os
+
+from dotenv import load_dotenv
 from sqlalchemy import create_engine, event
 from sqlalchemy.orm import sessionmaker
 
-# SQLite 数据库文件位置
-SQLALCHEMY_DATABASE_URL = "sqlite:///./data/demo.db"
+load_dotenv()
+
+# 数据库连接 URL，可从 .env 配置，默认 SQLite
+SQLALCHEMY_DATABASE_URL = os.getenv("SQLALCHEMY_DATABASE_URL", "sqlite:///./data/demo.db")
 
 # 创建数据库引擎
 # 增加 timeout=30 允许连接在遇到 locked 时最多等待 30 秒，而不是直接报错
diff --git a/backend/app/prompts/digest_email_template.py b/backend/app/prompts/digest_email_template.py
index 3827c8c..d34ea52 100644
--- a/backend/app/prompts/digest_email_template.py
+++ b/backend/app/prompts/digest_email_template.py
@@ -118,11 +118,11 @@ EVENT_CARD_TEMPLATE = """\
 
 def _hot_level(score: int) -> tuple[str, str, str]:
     """返回 (label, badge_class, hot_class)"""
-    if score >= 50:
-        return "全网沸腾", "badge-hot", " is-hot"
-    if score >= 20:
-        return "高度关注", "badge-warm", ""
     if score >= 10:
+        return "全网沸腾", "badge-hot", " is-hot"
+    if score >= 5:
+        return "高度关注", "badge-warm", ""
+    if score >= 3:
         return "上升中", "badge-normal", ""
     return "一般关注", "badge-tag", ""
 
diff --git a/backend/app/services/delivery_service.py b/backend/app/services/delivery_service.py
index 91e0e93..a568b24 100644
--- a/backend/app/services/delivery_service.py
+++ b/backend/app/services/delivery_service.py
@@ -1,6 +1,7 @@
 # 定时推送调度服务
 # 由 APScheduler 每分钟调用，检查当前时刻是否有用户需要接收推送，
 # 如匹配则生成摘要邮件并发送，同时写入 DeliveryHistory 防重复。
+# 推送优先级：有关键词且匹配 → 个性化简报；无关键词或无匹配 → 默认热点快报
 import logging
 import os
 from logging.handlers import TimedRotatingFileHandler
@@ -129,7 +130,7 @@ def _ensure_aware(dt: datetime) -> datetime:
 # 数据库查询辅助
 # ==========================================
 def _should_skip_by_interval(db: Session, user_id: int) -> bool:
-    """检查用户是否仍在 30 分钟冷却期内。"""
+    """检查用户是否仍在冷却期内，避免短时间内重复推送"""
     row = (
         db.query(DeliveryHistory.created_at)
         .filter(
@@ -330,7 +331,7 @@ def _prepare_user_push(db: Session, user: AppUser, schedule: UserDeliverySchedul
 
     pushed_ids = _get_already_pushed_event_ids(db, user_id)
 
-    # ——— 决策：匹配模式 or 默认模式 ———
+    # 决策：有关键词且有匹配 → 匹配模式；否则 → 默认热点模式
     items: list = []
     is_default = False
 
@@ -411,7 +412,7 @@ async def check_and_deliver() -> None:
             if not user:
                 continue
 
-            # 用户本地时间对比（核心时区修正）
+            # 将 UTC 转为用户本地时间，判断是否落在推送窗口内
             user_current = _user_local_time(now, user.timezone)
             if not _is_within_window(schedule.delivery_time, user_current):
                 continue
diff --git a/backend/app/services/fetcher_service.py b/backend/app/services/fetcher_service.py
index 2a25757..4cc71cc 100644
--- a/backend/app/services/fetcher_service.py
+++ b/backend/app/services/fetcher_service.py
@@ -1,4 +1,8 @@
 # app/services/fetcher_service.py
+"""
+抓取服务：从外部 API 拉取热搜/RSS 数据，做查重、向量聚类、入库
+热搜分支：语义聚类到 UnifiedEvent；RSS 分支：写入 NewsArticle
+"""
 import os
 import hashlib
 from datetime import timedelta
@@ -29,7 +33,7 @@ print("模型加载完成。")
 
 
 def generate_md5(text: str) -> str:
-    """生成32位MD5哈希值作为全局唯一指纹"""
+    """生成 32 位 MD5 作为 external_id，用于跨平台去重"""
     return hashlib.md5(text.encode('utf-8')).hexdigest()
 
 
@@ -66,6 +70,7 @@ class UnifiedEventClusterer:
                 self.event_ids.append(ev.id)
 
     def match_or_create(self, title: str, embedding_json: str, new_vec: np.ndarray) -> int:
+        """语义相似则归入已有事件并累加热度，否则创建新 UnifiedEvent"""
         if self.event_vectors:
             # 批量矩阵计算相似度
             sim_scores = cosine_similarity([new_vec], self.event_vectors)[0]
@@ -104,7 +109,7 @@ def process_hot_trend_item(db, source, item, index: int, external_id: str, exist
 
     event_to_log = None
 
-    # 核心逻辑：查重后再决定是否调用模型
+    # 查重：已存在则可能只需更新标题/排名；不存在则需聚类并新建
     if existing_event:
         # 场景 A1：老熟人
         if existing_event.current_headline != title:
@@ -204,7 +209,7 @@ def process_source_data(db, source, items: list) -> int:
     if not valid_items:
         return 0
 
-    # 2. 批量数据库查重
+    # 批量查重：按 external_id 判断是更新还是新增
     existing_events_dict = {}
     existing_articles_dict = {}
     
@@ -221,7 +226,7 @@ def process_source_data(db, source, items: list) -> int:
         ).all()
         existing_articles_dict = {art.external_id: art for art in existing_articles}
 
-    # 3. 筛选出需要进行大模型向量运算的文本
+    # 仅对需要算向量的标题做批量 embedding，避免重复计算
     texts_to_embed = []
     if source.source_type in (SourceType.HOT_TREND, SourceType.API):
         for item, external_id in valid_items:
@@ -241,7 +246,7 @@ def process_source_data(db, source, items: list) -> int:
     if source.source_type in (SourceType.HOT_TREND, SourceType.API):
         clusterer = UnifiedEventClusterer(db)
 
-    # 5. 核心路由分流落库
+    # 按来源类型分流：热搜/API → TrendingEvent + 聚类；RSS → NewsArticle
     for index, (item, external_id) in enumerate(valid_items, 1):
         if source.source_type in (SourceType.HOT_TREND, SourceType.API):
             existing_event = existing_events_dict.get(external_id)
diff --git a/backend/app/services/matching_service.py b/backend/app/services/matching_service.py
index d7a3832..0c48de5 100644
--- a/backend/app/services/matching_service.py
+++ b/backend/app/services/matching_service.py
@@ -1,3 +1,7 @@
+"""
+匹配服务：根据用户兴趣关键词（精确 + 语义）推荐事件
+打分融合：匹配分 + 标签相关度 + 热度 + 新鲜度加成
+"""
 import os
 from dataclasses import dataclass
 from datetime import datetime, timedelta, timezone
@@ -123,7 +127,7 @@ def recommend_events_for_user(
         else PREFERENCE_SEMANTIC_THRESHOLD
     )
 
-    # 读取用户兴趣词
+    # 1. 读取用户兴趣词
     preferences = (
         db.query(UserTopicPreference)
         .filter(UserTopicPreference.user_id == user_id)
@@ -136,7 +140,7 @@ def recommend_events_for_user(
     if not preference_keywords:
         return []
 
-    # 读取候选事件（先做时间和热度过滤，避免全表扫描）
+    # 2. 读取候选事件（时间 + 热度过滤，避免全表扫描）
     time_limit = utcnow() - timedelta(hours=hours)
     events = (
         db.query(UnifiedEvent)
@@ -177,7 +181,7 @@ def recommend_events_for_user(
     if not event_topics:
         return []
 
-    # 批量编码用户词和标签词，避免逐条调用模型
+    # 3. 批量编码用户词与标签词，减少模型调用次数
     unique_preference_keywords = list(dict.fromkeys(preference_keywords))
     unique_topic_keywords = list(dict.fromkeys([row[1] for row in topic_rows if row[1]]))
     pref_vec_map = _build_keyword_embedding_map(unique_preference_keywords)
@@ -196,7 +200,7 @@ def recommend_events_for_user(
         semantic_hits: list[dict[str, Any]] = []
         score = 0.0
 
-        # 对事件标签逐个匹配用户兴趣
+        # 对每个事件标签做精确匹配或语义匹配
         for topic_keyword, topic_relevance in topic_list:
             normalized_topic = _normalize_text(topic_keyword)
             topic_relevance_score = float(topic_relevance) if topic_relevance is not None else 50.0
diff --git a/backend/app/services/summary_service.py b/backend/app/services/summary_service.py
index e83aed9..e3b3cc1 100644
--- a/backend/app/services/summary_service.py
+++ b/backend/app/services/summary_service.py
@@ -1,4 +1,8 @@
 # app/services/summary_service.py
+"""
+摘要服务：调用 LLM 生成统一标题、综合摘要、话题标签
+定时任务：对热度达标且未摘要的事件批量处理
+"""
 import json
 import os
 from datetime import timedelta
@@ -36,7 +40,7 @@ deepseek_client = AsyncOpenAI(
 
 
 async def call_llm_for_summary(platform_data_text: str) -> dict:
-    """Call LLM for unified title, summary and topic candidates."""
+    """调用 LLM 生成统一标题、综合摘要、话题候选词"""
     prompt = SUMMARY_USER_PROMPT_TEMPLATE.format(platform_data_text=platform_data_text)
 
     response = await deepseek_client.chat.completions.create(
@@ -66,7 +70,7 @@ def _normalize_score(raw_score: Any) -> float | None:
 
 
 def parse_topic_keywords(llm_result: dict) -> list[dict[str, Any]]:
-    """Parse topic keywords from LLM response; support list[str] and list[object]."""
+    """解析 LLM 返回的话题关键词，支持字符串或对象格式"""
     raw_topics = llm_result.get("topic_keywords") or []
     parsed: list[dict[str, Any]] = []
     seen: set[str] = set()
@@ -103,7 +107,7 @@ def parse_topic_keywords(llm_result: dict) -> list[dict[str, Any]]:
 
 
 def normalize_topic_keywords(topic_candidates: list[dict[str, Any]]) -> list[dict[str, Any]]:
-    """Deduplicate semantically similar tags using embedding similarity."""
+    """用向量相似度去重同义标签，保留最具代表性的关键词"""
     if not topic_candidates:
         return []
 
@@ -159,7 +163,7 @@ def normalize_topic_keywords(topic_candidates: list[dict[str, Any]]) -> list[dic
 
 
 def replace_event_topics(db, event_id: int, normalized_topics: list[dict[str, Any]]) -> None:
-    """Replace EVENT tags for one unified event atomically within current transaction."""
+    """原子替换某事件的标签：先删旧再插新"""
     db.query(ExtractedTopic).filter(
         ExtractedTopic.target_type == TargetType.EVENT,
         ExtractedTopic.target_id == event_id,
@@ -177,7 +181,7 @@ def replace_event_topics(db, event_id: int, normalized_topics: list[dict[str, An
 
 
 async def generate_unified_summaries():
-    """Scheduled task: refresh summaries and topic tags for hot unified events."""
+    """定时任务：对热度达标且未摘要的事件刷新标题、摘要、标签"""
     print(f"[{utcnow()}] Start unified summary generation task...")
 
     # 先提取需要处理的事件 ID，尽早释放 session，不长期占用 db session
diff --git a/backend/app/utils/redis_client.py b/backend/app/utils/redis_client.py
new file mode 100644
index 0000000..e86df80
--- /dev/null
+++ b/backend/app/utils/redis_client.py
@@ -0,0 +1,57 @@
+import logging
+import os
+from typing import Optional, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from redis import Redis
+
+logger = logging.getLogger(__name__)
+
+try:
+    import redis  # type: ignore
+except ImportError:  # pragma: no cover
+    redis = None  # type: ignore
+
+
+REDIS_URL = os.getenv("REDIS_URL", "").strip()
+REDIS_CONNECT_TIMEOUT_SECONDS = float(os.getenv("REDIS_CONNECT_TIMEOUT_SECONDS", "2"))
+REDIS_SOCKET_TIMEOUT_SECONDS = float(os.getenv("REDIS_SOCKET_TIMEOUT_SECONDS", "2"))
+
+_redis_client: Optional["Redis"] = None
+_initialized = False
+
+
+def get_redis_client() -> Optional["Redis"]:
+    """Return a singleton Redis client, or None when Redis is unavailable."""
+    global _redis_client, _initialized
+
+    if _initialized:
+        return _redis_client
+
+    _initialized = True
+
+    if not REDIS_URL:
+        logger.info("REDIS_URL 未配置，验证码将回退到数据库存储")
+        _redis_client = None
+        return _redis_client
+
+    if redis is None:
+        logger.warning("未安装 redis 包，验证码将回退到数据库存储")
+        _redis_client = None
+        return _redis_client
+
+    try:
+        _redis_client = redis.Redis.from_url(
+            REDIS_URL,
+            decode_responses=True,
+            socket_connect_timeout=REDIS_CONNECT_TIMEOUT_SECONDS,
+            socket_timeout=REDIS_SOCKET_TIMEOUT_SECONDS,
+            health_check_interval=30,
+        )
+        _redis_client.ping()
+        logger.info("Redis 连接成功，验证码将优先使用 Redis")
+    except Exception as exc:  # pragma: no cover
+        logger.warning("Redis 连接失败，将回退到数据库存储。error=%s", exc)
+        _redis_client = None
+
+    return _redis_client
diff --git a/backend/logs/delivery_check.log.2026-03-11 b/backend/logs/delivery_check.log.2026-03-11
new file mode 100644
index 0000000..9f59bcd
--- /dev/null
+++ b/backend/logs/delivery_check.log.2026-03-11
@@ -0,0 +1,38 @@
+2026-03-11 18:27:39,440 [INFO] delivery_service: 推送调度检查 @ UTC 10:27
+2026-03-11 18:28:39,441 [INFO] delivery_service: 推送调度检查 @ UTC 10:28
+2026-03-11 18:28:39,445 [INFO] delivery_service: 用户 1 未配置关键词，使用默认热点模式
+2026-03-11 18:28:40,429 [INFO] delivery_service: 用户 1 邮件发送成功 → 1925008984@qq.com
+2026-03-11 18:29:39,433 [INFO] delivery_service: 推送调度检查 @ UTC 10:29
+2026-03-11 18:29:39,433 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-11 18:30:39,431 [INFO] delivery_service: 推送调度检查 @ UTC 10:30
+2026-03-11 18:30:39,432 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-11 18:31:39,430 [INFO] delivery_service: 推送调度检查 @ UTC 10:31
+2026-03-11 18:33:50,301 [INFO] delivery_service: 推送调度检查 @ UTC 10:33
+2026-03-11 18:34:50,295 [INFO] delivery_service: 推送调度检查 @ UTC 10:34
+2026-03-11 18:35:50,303 [INFO] delivery_service: 推送调度检查 @ UTC 10:35
+2026-03-11 18:36:50,303 [INFO] delivery_service: 推送调度检查 @ UTC 10:36
+2026-03-11 18:37:50,301 [INFO] delivery_service: 推送调度检查 @ UTC 10:37
+2026-03-11 18:38:50,302 [INFO] delivery_service: 推送调度检查 @ UTC 10:38
+2026-03-11 18:39:50,302 [INFO] delivery_service: 推送调度检查 @ UTC 10:39
+2026-03-11 18:40:50,304 [INFO] delivery_service: 推送调度检查 @ UTC 10:40
+2026-03-11 18:41:50,308 [INFO] delivery_service: 推送调度检查 @ UTC 10:41
+2026-03-11 18:42:50,562 [INFO] delivery_service: 推送调度检查 @ UTC 10:42
+2026-03-11 18:43:50,296 [INFO] delivery_service: 推送调度检查 @ UTC 10:43
+2026-03-11 18:44:50,297 [INFO] delivery_service: 推送调度检查 @ UTC 10:44
+2026-03-11 18:45:50,299 [INFO] delivery_service: 推送调度检查 @ UTC 10:45
+2026-03-11 18:46:50,301 [INFO] delivery_service: 推送调度检查 @ UTC 10:46
+2026-03-11 18:47:50,306 [INFO] delivery_service: 推送调度检查 @ UTC 10:47
+2026-03-11 18:48:50,299 [INFO] delivery_service: 推送调度检查 @ UTC 10:48
+2026-03-11 18:49:50,304 [INFO] delivery_service: 推送调度检查 @ UTC 10:49
+2026-03-11 18:50:50,306 [INFO] delivery_service: 推送调度检查 @ UTC 10:50
+2026-03-11 18:51:50,309 [INFO] delivery_service: 推送调度检查 @ UTC 10:51
+2026-03-11 18:52:50,321 [INFO] delivery_service: 推送调度检查 @ UTC 10:52
+2026-03-11 18:53:50,298 [INFO] delivery_service: 推送调度检查 @ UTC 10:53
+2026-03-11 18:54:50,298 [INFO] delivery_service: 推送调度检查 @ UTC 10:54
+2026-03-11 18:55:50,303 [INFO] delivery_service: 推送调度检查 @ UTC 10:55
+2026-03-11 18:56:50,298 [INFO] delivery_service: 推送调度检查 @ UTC 10:56
+2026-03-11 20:32:14,068 [INFO] delivery_service: 用户 5 关键词匹配，推送 3 条事件
+2026-03-11 20:32:15,198 [INFO] delivery_service: 用户 5 邮件发送成功 → 2170308303@qq.com
+2026-03-11 20:33:13,661 [INFO] delivery_service: 用户 5 仍在 30 分钟冷却期内，跳过
+2026-03-11 20:34:13,657 [INFO] delivery_service: 用户 5 仍在 30 分钟冷却期内，跳过
+2026-03-11 20:35:13,662 [INFO] delivery_service: 用户 5 仍在 30 分钟冷却期内，跳过
diff --git a/backend/logs/delivery_check.log.2026-03-12 b/backend/logs/delivery_check.log.2026-03-12
new file mode 100644
index 0000000..289e31a
--- /dev/null
+++ b/backend/logs/delivery_check.log.2026-03-12
@@ -0,0 +1,14 @@
+2026-03-12 08:28:37,678 [INFO] delivery_service: 用户 1 关键词匹配，推送 6 条事件
+2026-03-12 08:28:39,467 [INFO] delivery_service: 用户 1 邮件发送成功 → 1925008984@qq.com
+2026-03-12 08:29:37,533 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-12 08:30:37,536 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-12 08:31:37,532 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-12 08:32:37,531 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-12 18:27:29,895 [INFO] delivery_service: 用户 1 关键词匹配，推送 6 条事件
+2026-03-12 18:27:31,306 [INFO] delivery_service: 用户 1 邮件发送成功 → 1925008984@qq.com
+2026-03-12 18:28:29,849 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-12 18:29:29,849 [INFO] delivery_service: 用户 1 仍在 30 分钟冷却期内，跳过
+2026-03-12 20:32:49,821 [INFO] delivery_service: 用户 5 关键词匹配，推送 6 条事件
+2026-03-12 20:32:51,028 [INFO] delivery_service: 用户 5 邮件发送成功 → 2170308303@qq.com
+2026-03-12 20:33:49,671 [INFO] delivery_service: 用户 5 仍在 30 分钟冷却期内，跳过
+2026-03-12 20:34:49,680 [INFO] delivery_service: 用户 5 仍在 30 分钟冷却期内，跳过
diff --git a/frontend/src/App.vue b/frontend/src/App.vue
index d14fc99..224739f 100644
--- a/frontend/src/App.vue
+++ b/frontend/src/App.vue
@@ -1,3 +1,4 @@
+<!-- 根组件：路由出口，带页面切换淡入淡出动画 -->
 <template>
   <RouterView v-slot="{ Component }">
     <transition name="page-fade" mode="out-in">
diff --git a/frontend/src/api/client.ts b/frontend/src/api/client.ts
index c3cb54c..b2446aa 100644
--- a/frontend/src/api/client.ts
+++ b/frontend/src/api/client.ts
@@ -5,7 +5,7 @@ import { useAuthStore } from '@/stores/auth'
 import { pinia } from '@/stores'
 import { fetchApi } from '@/config/apiBase'
 
-// 后端错误消息中英文映射。
+// 后端英文错误消息到中文的映射
 const MESSAGE_MAP: Record<string, string> = {
   'You can only operate your own resources': '只能操作你自己的资源',
   'Preference keyword already exists for this user': '该关键词已经订阅过了',
diff --git a/frontend/src/api/events.ts b/frontend/src/api/events.ts
index c21b4ef..a92bfb9 100644
--- a/frontend/src/api/events.ts
+++ b/frontend/src/api/events.ts
@@ -36,7 +36,7 @@ export function searchEventsTimeline(
   hours: number = 168,
   mode: 'exact' | 'semantic' | 'hybrid' = 'hybrid'
 ): Promise<SearchTimelineResponse> {
-  // JS 的 getTimezoneOffset: 本地 - UTC（东八区是 -480），这里转成 UTC+ 偏移分钟。
+  // 获取客户端时区偏移：getTimezoneOffset 为 本地-UTC 分钟，东八区为 -480，转为 UTC+ 偏移
   const utcOffsetMinutes = -new Date().getTimezoneOffset()
   return apiGet<SearchTimelineResponse>('/events/search_timeline', {
     keyword,
diff --git a/frontend/src/auth.api.ts b/frontend/src/auth.api.ts
index 03d4bd0..18546ba 100644
--- a/frontend/src/auth.api.ts
+++ b/frontend/src/auth.api.ts
@@ -1,3 +1,6 @@
+/**
+ * 认证 API：登录、注册、发送验证码（不走通用 client，无 Bearer）
+ */
 import type {
   AuthTokenResponse,
   LoginPayload,
diff --git a/frontend/src/components/BrandLogo.vue b/frontend/src/components/BrandLogo.vue
index dd0990c..147a6f7 100644
--- a/frontend/src/components/BrandLogo.vue
+++ b/frontend/src/components/BrandLogo.vue
@@ -1,3 +1,4 @@
+<!-- 品牌 Logo：雷达扫描风格 SVG，带呼吸灯与旋转动画 -->
 <template>
   <div class="brand-logo-container">
     <svg class="insight-logo" viewBox="0 0 32 32" fill="none" xmlns="http://www.w3.org/2000/svg">
diff --git a/frontend/src/components/CustomSelect.vue b/frontend/src/components/CustomSelect.vue
new file mode 100644
index 0000000..2e17507
--- /dev/null
+++ b/frontend/src/components/CustomSelect.vue
@@ -0,0 +1,201 @@
+<script setup lang="ts">
+import { ref, onMounted, onUnmounted } from 'vue'
+
+const props = defineProps<{
+  modelValue: string | number
+  options: { label: string; value: string | number }[]
+  icon: string
+}>()
+
+const emit = defineEmits<{
+  (e: 'update:modelValue', value: string | number): void
+}>()
+
+const isOpen = ref(false)
+const selectRef = ref<HTMLElement | null>(null)
+
+const toggle = () => {
+  isOpen.value = !isOpen.value
+}
+
+const selectOption = (value: string | number) => {
+  emit('update:modelValue', value)
+  isOpen.value = false
+}
+
+const handleClickOutside = (event: MouseEvent) => {
+  if (selectRef.value && !selectRef.value.contains(event.target as Node)) {
+    isOpen.value = false
+  }
+}
+
+onMounted(() => {
+  document.addEventListener('click', handleClickOutside)
+})
+
+onUnmounted(() => {
+  document.removeEventListener('click', handleClickOutside)
+})
+</script>
+
+<template>
+  <div class="custom-select-wrapper" ref="selectRef">
+    <i :class="['select-icon', icon]"></i>
+    <div class="select-trigger" :class="{ 'is-open': isOpen }" @click="toggle">
+      <span class="selected-label">
+        {{ options.find(o => o.value === modelValue)?.label }}
+      </span>
+      <i class="fa-solid fa-chevron-down select-arrow"></i>
+    </div>
+
+    <transition name="dropdown">
+      <ul v-if="isOpen" class="select-dropdown">
+        <li
+          v-for="option in options"
+          :key="option.value"
+          class="select-option"
+          :class="{ 'is-active': option.value === modelValue }"
+          @click="selectOption(option.value)"
+        >
+          {{ option.label }}
+        </li>
+      </ul>
+    </transition>
+  </div>
+</template>
+
+<style scoped>
+.custom-select-wrapper {
+  position: relative;
+  display: flex;
+  align-items: center;
+  min-width: 140px;
+}
+
+.select-icon {
+  position: absolute;
+  left: 14px;
+  color: var(--text-placeholder);
+  font-size: 14px;
+  pointer-events: none;
+  z-index: 2;
+  transition: color 0.2s;
+}
+
+.select-arrow {
+  position: absolute;
+  right: 12px;
+  color: var(--text-placeholder);
+  font-size: 11px;
+  pointer-events: none;
+  z-index: 2;
+  transition: color 0.2s, transform 0.2s;
+}
+
+.select-trigger {
+  width: 100%;
+  padding: 12px 34px 12px 38px;
+  border: 1px solid var(--border-subtle);
+  border-radius: var(--radius-lg);
+  background-color: var(--bg-input);
+  color: var(--text-primary);
+  font-size: 14px;
+  font-weight: 500;
+  cursor: pointer;
+  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
+  display: flex;
+  align-items: center;
+  user-select: none;
+  white-space: nowrap;
+}
+
+.select-trigger:hover {
+  border-color: var(--border-strong);
+  background-color: var(--bg-surface);
+}
+
+.select-trigger.is-open {
+  border-color: var(--brand-primary);
+  box-shadow: 0 0 0 3px var(--brand-primary-alpha);
+  background-color: var(--bg-surface);
+}
+
+.select-trigger.is-open .select-arrow {
+  transform: rotate(180deg);
+  color: var(--brand-primary);
+}
+
+.custom-select-wrapper:hover .select-icon,
+.custom-select-wrapper:hover .select-arrow {
+  color: var(--brand-primary);
+}
+
+.select-dropdown {
+  position: absolute;
+  top: calc(100% + 8px);
+  left: 0;
+  width: 100%;
+  min-width: 100%;
+  margin: 0;
+  padding: 6px;
+  list-style: none;
+  background: var(--bg-surface);
+  backdrop-filter: var(--backdrop-blur, blur(12px));
+  -webkit-backdrop-filter: var(--backdrop-blur, blur(12px));
+  border: 1px solid var(--border-subtle);
+  border-radius: var(--radius-lg);
+  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
+  z-index: 100;
+  max-height: 250px;
+  overflow-y: auto;
+}
+
+.select-option {
+  padding: 10px 12px;
+  border-radius: var(--radius-md);
+  font-size: 14px;
+  color: var(--text-secondary);
+  cursor: pointer;
+  transition: all 0.2s;
+  margin-bottom: 2px;
+  white-space: nowrap;
+}
+
+.select-option:last-child {
+  margin-bottom: 0;
+}
+
+.select-option:hover {
+  background-color: var(--bg-input);
+  color: var(--text-primary);
+}
+
+.select-option.is-active {
+  background-color: var(--brand-primary-alpha);
+  color: var(--brand-primary);
+  font-weight: 600;
+}
+
+/* 滚动条美化 */
+.select-dropdown::-webkit-scrollbar {
+  width: 4px;
+}
+.select-dropdown::-webkit-scrollbar-track {
+  background: transparent;
+}
+.select-dropdown::-webkit-scrollbar-thumb {
+  background-color: var(--border-strong);
+  border-radius: 4px;
+}
+
+/* 过渡动画 */
+.dropdown-enter-active,
+.dropdown-leave-active {
+  transition: opacity 0.2s ease, transform 0.2s ease;
+}
+.dropdown-enter-from,
+.dropdown-leave-to {
+  opacity: 0;
+  transform: translateY(-8px);
+}
+</style>
diff --git a/frontend/src/components/ThemeToggle.vue b/frontend/src/components/ThemeToggle.vue
index ec9ab2f..f010353 100644
--- a/frontend/src/components/ThemeToggle.vue
+++ b/frontend/src/components/ThemeToggle.vue
@@ -4,17 +4,17 @@ import { useThemeStore } from '@/stores/theme'
 const themeStore = useThemeStore()
 
 /**
- * 切换主题，使用 View Transitions API 实现高级扩散动画（如果浏览器支持）
- * 这种动画比之前像玩具一样的开关要高级得多，提供原生级的丝滑过渡
+ * 切换主题：支持 View Transitions API 时使用点击位置扩散动画，
+ * 否则直接切换
  */
 function handleToggle(event: MouseEvent) {
-  // 检查浏览器是否支持 document.startViewTransition 并且用户没有开启减弱动画
+  // 检测浏览器是否支持 View Transitions 且用户未开启减弱动画
   const isAppearanceTransition = typeof document !== 'undefined' && 
                                  'startViewTransition' in document && 
                                  !window.matchMedia('(prefers-reduced-motion: reduce)').matches
 
   if (!isAppearanceTransition) {
-    // 降级处理：直接切换
+    // 不支持时直接切换，无动画
     themeStore.toggleTheme()
     return
   }
diff --git a/frontend/src/components/UnifiedEventCard.vue b/frontend/src/components/UnifiedEventCard.vue
index 781005c..cd0aa4e 100644
--- a/frontend/src/components/UnifiedEventCard.vue
+++ b/frontend/src/components/UnifiedEventCard.vue
@@ -1,3 +1,4 @@
+<!-- 统一事件卡片：展示标题、摘要、平台来源、排名轨迹，悬停展开图表 -->
 <script setup lang="ts">
 import { ref } from 'vue'
 import { useRouter } from 'vue-router'
diff --git a/frontend/src/config/apiBase.ts b/frontend/src/config/apiBase.ts
index a6d5d50..6833e0b 100644
--- a/frontend/src/config/apiBase.ts
+++ b/frontend/src/config/apiBase.ts
@@ -1,3 +1,6 @@
+/**
+ * API 基础配置：自动探测内网/公网后端，失败时回退公网
+ */
 const API_PREFIX = '/api/v1'
 const LAN_BACKEND_ORIGIN = 'http://10.252.130.135:8000'
 const PUBLIC_BACKEND_ORIGIN = 'http://47.107.130.88:51290'
@@ -42,6 +45,7 @@ function isLanHostname(hostname: string): boolean {
   return isPrivateIpv4(normalized)
 }
 
+// 探测内网后端是否可用（请求 openapi.json）
 async function probeLanBackend(): Promise<boolean> {
   if (typeof window === 'undefined') return false
 
@@ -69,6 +73,7 @@ async function probeLanBackend(): Promise<boolean> {
   }
 }
 
+// 根据当前 hostname 与探测结果选择内网或公网 API 地址
 async function detectApiBaseUrl(): Promise<string> {
   if (ENV_API_BASE_URL) return ENV_API_BASE_URL
   if (typeof window === 'undefined') return PUBLIC_API_BASE_URL
diff --git a/frontend/src/layouts/DashboardLayout.vue b/frontend/src/layouts/DashboardLayout.vue
index c56e52c..8d530c2 100644
--- a/frontend/src/layouts/DashboardLayout.vue
+++ b/frontend/src/layouts/DashboardLayout.vue
@@ -1,3 +1,4 @@
+<!-- 仪表盘布局：侧边栏导航、主内容区、移动端抽屉 -->
 <script setup lang="ts">
 import { computed, ref } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
diff --git a/frontend/src/main.ts b/frontend/src/main.ts
index 793c39b..3253a1c 100644
--- a/frontend/src/main.ts
+++ b/frontend/src/main.ts
@@ -1,3 +1,6 @@
+/**
+ * 应用入口：初始化 Vue、Pinia、路由、主题
+ */
 import './assets/main.css'
 
 import { createApp } from 'vue'
@@ -9,6 +12,7 @@ import { useThemeStore } from './stores/theme'
 
 const app = createApp(App)
 
+// 先挂载 Pinia，再初始化主题（依赖 Pinia）
 app.use(pinia)
 const themeStore = useThemeStore(pinia)
 themeStore.initTheme()
diff --git a/frontend/src/router/index.ts b/frontend/src/router/index.ts
index f437c6d..f56b875 100644
--- a/frontend/src/router/index.ts
+++ b/frontend/src/router/index.ts
@@ -1,3 +1,6 @@
+/**
+ * 路由配置：认证页（guestOnly）、仪表盘子路由（requiresAuth）
+ */
 import { createRouter, createWebHistory } from 'vue-router'
 
 import { pinia } from '@/stores'
@@ -59,6 +62,7 @@ const router = createRouter({
   ],
 })
 
+// 全局前置守卫：认证校验、未登录重定向
 router.beforeEach((to) => {
   const authStore = useAuthStore(pinia)
   authStore.restore()
diff --git a/frontend/src/stores/auth.ts b/frontend/src/stores/auth.ts
index 8313f08..d4a2064 100644
--- a/frontend/src/stores/auth.ts
+++ b/frontend/src/stores/auth.ts
@@ -1,3 +1,6 @@
+/**
+ * 认证状态：Token、用户信息持久化，登录/注册/登出
+ */
 import { computed, ref } from 'vue'
 import { defineStore } from 'pinia'
 
@@ -12,6 +15,7 @@ interface PersistedAuthState {
 
 const AUTH_STORAGE_KEY = 'insight-radar-auth'
 
+// 从 localStorage 恢复登录状态
 function loadPersistedState(): PersistedAuthState | null {
   const raw = localStorage.getItem(AUTH_STORAGE_KEY)
   if (!raw) {
diff --git a/frontend/src/stores/theme.ts b/frontend/src/stores/theme.ts
index b7a7de0..05c87eb 100644
--- a/frontend/src/stores/theme.ts
+++ b/frontend/src/stores/theme.ts
@@ -1,3 +1,6 @@
+/**
+ * 主题状态：深色/浅色切换，持久化到 localStorage，支持系统偏好
+ */
 import { computed, ref } from 'vue'
 import { defineStore } from 'pinia'
 
diff --git a/frontend/src/views/AboutView.vue b/frontend/src/views/AboutView.vue
index 756ad2a..4b0f3e3 100644
--- a/frontend/src/views/AboutView.vue
+++ b/frontend/src/views/AboutView.vue
@@ -1,6 +1,7 @@
+<!-- 关于页（占位） -->
 <template>
   <div class="about">
-    <h1>This is an about page</h1>
+    <h1>关于 InsightRadar</h1>
   </div>
 </template>
 
diff --git a/frontend/src/views/DashboardView.vue b/frontend/src/views/DashboardView.vue
index d8557f6..36d3307 100644
--- a/frontend/src/views/DashboardView.vue
+++ b/frontend/src/views/DashboardView.vue
@@ -1,3 +1,4 @@
+<!-- 主仪表盘：事件流、为你推荐、公关修改追踪、系统状态 -->
 <script setup lang="ts">
 import { onMounted, ref, computed, watch } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
diff --git a/frontend/src/views/DeliveryView.vue b/frontend/src/views/DeliveryView.vue
index 429c6ab..742f9f0 100644
--- a/frontend/src/views/DeliveryView.vue
+++ b/frontend/src/views/DeliveryView.vue
@@ -1,3 +1,4 @@
+<!-- 推送设置页：管理推送时间表与推送渠道（邮箱等） -->
 <script setup lang="ts">
 import { onMounted, ref, computed } from 'vue'
 
diff --git a/frontend/src/views/HomeView.vue b/frontend/src/views/HomeView.vue
index cb92c9b..c3b4587 100644
--- a/frontend/src/views/HomeView.vue
+++ b/frontend/src/views/HomeView.vue
@@ -1,3 +1,4 @@
+<!-- 概览页：展示当前账户、会话状态、认证接入说明 -->
 <script setup lang="ts">
 import { computed } from 'vue'
 import { useRouter } from 'vue-router'
diff --git a/frontend/src/views/LoginView.vue b/frontend/src/views/LoginView.vue
index d02b31c..d545c4e 100644
--- a/frontend/src/views/LoginView.vue
+++ b/frontend/src/views/LoginView.vue
@@ -1,3 +1,4 @@
+<!-- 登录页：支持密码登录与邮箱验证码登录 -->
 <script setup lang="ts">
 import { computed, onUnmounted, reactive, ref, watch } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
@@ -8,6 +9,7 @@ import { useAuthStore } from '@/stores/auth'
 
 type LoginMode = 'password' | 'code'
 
+// 验证码重发冷却时间（秒）
 const CODE_RESEND_SECONDS = 60
 
 const authStore = useAuthStore()
diff --git a/frontend/src/views/RegisterView.vue b/frontend/src/views/RegisterView.vue
index 1d445e7..07beda6 100644
--- a/frontend/src/views/RegisterView.vue
+++ b/frontend/src/views/RegisterView.vue
@@ -1,3 +1,4 @@
+<!-- 注册页：邮箱验证码 + 密码，带密码强度提示 -->
 <script setup lang="ts">
 import { computed, onUnmounted, reactive, ref } from 'vue'
 import { useRouter } from 'vue-router'
@@ -34,7 +35,7 @@ const canSendCode = computed(() => {
   return /^[^@\s]+@[^@\s]+\.[^@\s]+$/.test(form.email)
 })
 
-// === 新增：密码强度计算逻辑 ===
+// 密码强度：根据长度、字母、数字、特殊字符计算 0~4 档
 const passwordStrength = computed(() => {
   const pwd = form.password
   if (!pwd) return 0
@@ -52,8 +53,6 @@ const strengthColor = computed(() => {
   return colors[passwordStrength.value]
 })
 
-// ==========================
-
 function startCooldown(seconds = CODE_RESEND_SECONDS) {
   countdown.value = Math.max(1, seconds)
   if (countdownTimer) clearInterval(countdownTimer)
diff --git a/frontend/src/views/RevisionsView.vue b/frontend/src/views/RevisionsView.vue
index 25d3736..6f04fd5 100644
--- a/frontend/src/views/RevisionsView.vue
+++ b/frontend/src/views/RevisionsView.vue
@@ -1,3 +1,4 @@
+<!-- 公关修改追踪页：展示热搜标题被偷偷修改的历史记录 -->
 <script setup lang="ts">
 import { computed, onMounted, ref } from 'vue'
 
diff --git a/frontend/src/views/SearchView.vue b/frontend/src/views/SearchView.vue
index 6d14868..49c59fe 100644
--- a/frontend/src/views/SearchView.vue
+++ b/frontend/src/views/SearchView.vue
@@ -1,9 +1,11 @@
+<!-- 事件追踪分析页：关键词搜索、时间热度图表、关联事件列表 -->
 <script setup lang="ts">
 import { ref, computed } from 'vue'
 import VueApexCharts from 'vue3-apexcharts'
 import { searchEventsTimeline } from '@/api/events'
 import type { SearchTimelineResponse } from '@/types/event'
 import UnifiedEventCard from '@/components/UnifiedEventCard.vue'
+import CustomSelect from '@/components/CustomSelect.vue'
 
 const keyword = ref('')
 const searchResult = ref<SearchTimelineResponse | null>(null)
@@ -12,6 +14,22 @@ const hours = ref(2)
 const searchMode = ref<'exact' | 'semantic' | 'hybrid'>('hybrid')
 const selectedTimeLabel = ref<string | null>(null)
 
+const timeOptions = [
+  { label: '最近 2 小时', value: 2 },
+  { label: '最近 12 小时', value: 12 },
+  { label: '最近 24 小时', value: 24 },
+  { label: '最近 48 小时', value: 48 },
+  { label: '最近 7 天', value: 168 },
+  { label: '最近 15 天', value: 360 }
+]
+
+const modeOptions = [
+  { label: '混合匹配', value: 'hybrid' },
+  { label: '关键词匹配', value: 'exact' },
+  { label: '语义匹配', value: 'semantic' }
+]
+
+// 根据选中的时间点筛选事件：点击图表节点时只显示该时间点关联的事件
 const filteredEvents = computed(() => {
   if (!searchResult.value) return []
   if (!selectedTimeLabel.value) return searchResult.value.events
@@ -51,6 +69,7 @@ const chartOptions = ref({
       easing: 'easeinout',
       speed: 800,
     },
+    // 点击图表数据点：切换选中时间，再次点击则取消筛选
     events: {
       markerClick: function(event: any, chartContext: any, { dataPointIndex }: any) {
         if (searchResult.value && searchResult.value.timeline[dataPointIndex]) {
@@ -188,27 +207,16 @@ async function handleSearch() {
                 class="search-input"
               />
             </div>
-            <div class="time-select-wrapper">
-              <i class="fa-regular fa-clock select-icon"></i>
-              <select v-model="hours" class="time-select">
-                <option :value="2">最近 2 小时</option>
-                <option :value="12">最近 12 小时</option>
-                <option :value="24">最近 24 小时</option>
-                <option :value="48">最近 48 小时</option>
-                <option :value="168">最近 7 天</option>
-                <option :value="360">最近 15 天</option>
-              </select>
-              <i class="fa-solid fa-chevron-down select-arrow"></i>
-            </div>
-            <div class="time-select-wrapper">
-              <i class="fa-solid fa-filter select-icon"></i>
-              <select v-model="searchMode" class="time-select">
-                <option value="hybrid">混合匹配</option>
-                <option value="exact">关键词匹配</option>
-                <option value="semantic">语义匹配</option>
-              </select>
-              <i class="fa-solid fa-chevron-down select-arrow"></i>
-            </div>
+            <CustomSelect
+              v-model="hours"
+              :options="timeOptions"
+              icon="fa-regular fa-clock"
+            />
+            <CustomSelect
+              v-model="searchMode"
+              :options="modeOptions"
+              icon="fa-solid fa-filter"
+            />
             <button class="btn btn-primary" @click="handleSearch" :disabled="loading || !keyword.trim()">
               <i class="fa-solid fa-bolt" v-if="!loading"></i>
               <i class="fa-solid fa-spinner fa-spin" v-else></i>
@@ -359,6 +367,8 @@ async function handleSearch() {
   display: flex;
   gap: 24px;
   align-items: stretch;
+  position: relative;
+  z-index: 10; /* 确保搜索框及下拉选择框显示在下方图表之上 */
 }
 
 .search-box {
@@ -470,61 +480,6 @@ async function handleSearch() {
   background-color: var(--bg-surface);
 }
 
-.time-select-wrapper {
-  position: relative;
-  display: flex;
-  align-items: center;
-  min-width: 160px;
-}
-
-.select-icon {
-  position: absolute;
-  left: 14px;
-  color: var(--text-placeholder);
-  font-size: 15px;
-  pointer-events: none;
-  z-index: 1;
-}
-
-.select-arrow {
-  position: absolute;
-  right: 14px;
-  color: var(--text-placeholder);
-  font-size: 12px;
-  pointer-events: none;
-}
-
-.time-select {
-  width: 100%;
-  padding: 14px 36px 14px 40px;
-  border: 1px solid var(--border-subtle);
-  border-radius: var(--radius-lg);
-  background-color: var(--bg-input);
-  color: var(--text-primary);
-  font-size: 14px;
-  font-weight: 500;
-  cursor: pointer;
-  transition: all 0.2s;
-  appearance: none;
-  -webkit-appearance: none;
-}
-
-.time-select:focus {
-  outline: none;
-  border-color: var(--brand-primary);
-  box-shadow: 0 0 0 3px var(--brand-primary-alpha);
-  background-color: var(--bg-surface);
-}
-
-.time-select-wrapper:hover .time-select {
-  border-color: var(--brand-primary);
-}
-
-.time-select-wrapper:hover .select-icon,
-.time-select-wrapper:hover .select-arrow {
-  color: var(--brand-primary);
-}
-
 .btn-primary {
   display: inline-flex;
   align-items: center;
@@ -562,6 +517,8 @@ async function handleSearch() {
   flex-direction: column;
   gap: 24px;
   animation: fadeIn 0.4s ease-out;
+  position: relative;
+  z-index: 1; /* 低于 top-panels，避免图表覆盖搜索框下拉 */
 }
 
 .section-header {
diff --git a/frontend/src/views/TopicsView.vue b/frontend/src/views/TopicsView.vue
index f8d1c15..49c4627 100644
--- a/frontend/src/views/TopicsView.vue
+++ b/frontend/src/views/TopicsView.vue
@@ -1,3 +1,4 @@
+<!-- 兴趣关键词页：添加/删除关键词，查看命中事件 -->
 <script setup lang="ts">
 import { onMounted, ref, computed } from 'vue'