diff --git a/.gitignore b/.gitignore
index 1e88ecf..dc9b4d1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -49,4 +49,5 @@ docs/
 feature.md
 livePlan.md
 Promotion.md
+wordsFilter.md
 .env.local
diff --git a/app/_layout.tsx b/app/_layout.tsx
index b89e078..3058fb9 100644
--- a/app/_layout.tsx
+++ b/app/_layout.tsx
@@ -6,6 +6,7 @@ import { useEffect } from 'react';
 import { useAuthStore } from '../store/authStore';
 import { useDownloadStore } from '../store/downloadStore';
 import { useSettingsStore } from '../store/settingsStore';
+import { useTheme } from '../utils/theme';
 import { MiniPlayer } from '../components/MiniPlayer';
 import * as Sentry from '@sentry/react-native';
 import { ErrorBoundary } from '@sentry/react-native';
@@ -21,6 +22,7 @@ function RootLayout() {
   const restore = useAuthStore(s => s.restore);
   const loadDownloads = useDownloadStore(s => s.loadFromStorage);
   const restoreSettings = useSettingsStore(s => s.restore);
+  const darkMode = useSettingsStore(s => s.darkMode);
 
   useEffect(() => {
     restore();
@@ -31,7 +33,7 @@ function RootLayout() {
 
   return (
     <SafeAreaProvider>
-      <StatusBar style="dark" />
+      <StatusBar style={darkMode ? 'light' : 'dark'} />
       <View style={{ flex: 1 }}>
         <ErrorBoundary fallback={<Text style={{ padding: 32, textAlign: 'center' }}>发生错误，请重启 App</Text>}>
           <Stack screenOptions={{ headerShown: false }}>
diff --git a/app/downloads.tsx b/app/downloads.tsx
index 72c5e4d..0f19eaf 100644
--- a/app/downloads.tsx
+++ b/app/downloads.tsx
@@ -27,9 +27,11 @@ function formatFileSize(bytes?: number): string {
   return `${(bytes / (1024 * 1024 * 1024)).toFixed(2)} GB`;
 }
 import { proxyImageUrl } from '../utils/imageUrl';
+import { useTheme } from '../utils/theme';
 
 export default function DownloadsScreen() {
   const router = useRouter();
+  const theme = useTheme();
   const { tasks, loadFromStorage, removeTask } = useDownloadStore();
   const [playingUri, setPlayingUri] = useState<string | null>(null);
   const [playingTitle, setPlayingTitle] = useState('');
@@ -61,12 +63,12 @@ export default function DownloadsScreen() {
   if (done.length > 0) sections.push({ title: '已下载', data: done });
 
   return (
-    <SafeAreaView style={styles.safe}>
-      <View style={styles.topBar}>
+    <SafeAreaView style={[styles.safe, { backgroundColor: theme.bg }]}>
+      <View style={[styles.topBar, { backgroundColor: theme.card, borderBottomColor: theme.border }]}>
         <TouchableOpacity onPress={() => router.back()} style={styles.backBtn}>
-          <Ionicons name="chevron-back" size={24} color="#212121" />
+          <Ionicons name="chevron-back" size={24} color={theme.text} />
         </TouchableOpacity>
-        <Text style={styles.topTitle}>我的下载</Text>
+        <Text style={[styles.topTitle, { color: theme.text }]}>我的下载</Text>
         <View style={{ width: 32 }} />
       </View>
 
diff --git a/app/index.tsx b/app/index.tsx
index 2521408..0350335 100644
--- a/app/index.tsx
+++ b/app/index.tsx
@@ -40,6 +40,7 @@ import {
 } from "../utils/videoRows";
 import { BigVideoCard } from "../components/BigVideoCard";
 import { FollowedLiveStrip } from "../components/FollowedLiveStrip";
+import { useTheme } from "../utils/theme";
 import type { LiveRoom } from "../services/types";
 
 const HEADER_H = 44;
@@ -83,6 +84,7 @@ export default function HomeScreen() {
   const [activeTab, setActiveTab] = useState<TabKey>("hot");
   const [liveAreaId, setLiveAreaId] = useState(0);
 
+  const theme = useTheme();
   const [visibleBigKey, setVisibleBigKey] = useState<string | null>(null);
   const rows = useMemo(() => toListRows(pages, liveRooms), [pages, liveRooms]);
   const pagerRef = useRef<PagerView>(null);
@@ -286,7 +288,7 @@ export default function HomeScreen() {
     activeTab === "hot" ? headerOpacity : liveHeaderOpacity;
 
   return (
-    <SafeAreaView style={styles.safe} edges={["left", "right"]}>
+    <SafeAreaView style={[styles.safe, { backgroundColor: theme.bg }]} edges={["left", "right"]}>
       {/* 滑动切换容器 */}
       <PagerView
         ref={pagerRef}
@@ -410,6 +412,7 @@ export default function HomeScreen() {
           styles.navBar,
           {
             paddingTop: insets.top,
+            backgroundColor: theme.card,
             transform: [{ translateY: currentHeaderTranslate }],
           },
         ]}
@@ -419,6 +422,7 @@ export default function HomeScreen() {
             styles.header,
             {
               opacity: currentHeaderOpacity,
+              borderBottomColor: theme.border,
             },
           ]}
         >
@@ -439,19 +443,19 @@ export default function HomeScreen() {
             </TouchableOpacity>
           </View>
           <TouchableOpacity
-            style={styles.searchBar}
+            style={[styles.searchBar, { backgroundColor: theme.inputBg }]}
             onPress={() => router.push("/search" as any)}
             activeOpacity={0.7}
           >
-            <Ionicons name="search" size={14} color="#999" />
-            <Text style={styles.searchPlaceholder}>搜索视频、UP主...</Text>
+            <Ionicons name="search" size={14} color={theme.textSub} />
+            <Text style={[styles.searchPlaceholder, { color: theme.textSub }]}>搜索视频、UP主...</Text>
           </TouchableOpacity>
           <DownloadProgressBtn
             onPress={() => router.push("/downloads" as any)}
           />
         </Animated.View>
 
-        <View style={styles.tabRow}>
+        <View style={[styles.tabRow, { backgroundColor: theme.card }]}>
           {TABS.map((tab) => (
             <TouchableOpacity
               key={tab.key}
@@ -462,6 +466,7 @@ export default function HomeScreen() {
               <Text
                 style={[
                   styles.tabText,
+                  { color: theme.textSub },
                   activeTab === tab.key && styles.tabTextActive,
                 ]}
               >
diff --git a/app/search.tsx b/app/search.tsx
index 12324ee..ff20aa2 100644
--- a/app/search.tsx
+++ b/app/search.tsx
@@ -13,11 +13,13 @@ import { useRouter } from 'expo-router';
 import { Ionicons } from '@expo/vector-icons';
 import { VideoCard } from '../components/VideoCard';
 import { useSearch } from '../hooks/useSearch';
+import { useTheme } from '../utils/theme';
 import type { VideoItem } from '../services/types';
 
 export default function SearchScreen() {
   const router = useRouter();
   const { keyword, setKeyword, results, loading, hasMore, search, loadMore } = useSearch();
+  const theme = useTheme();
   const inputRef = useRef<TextInput>(null);
 
   const handleSearch = useCallback(() => {
@@ -64,7 +66,7 @@ export default function SearchScreen() {
     return (
       <View style={styles.emptyBox}>
         <Ionicons name="search-outline" size={48} color="#ddd" />
-        <Text style={styles.emptyText}>
+        <Text style={[styles.emptyText, { color: theme.textSub }]}>
           {results.length === 0 && keyword.trim()
             ? '没有找到相关视频'
             : '输入关键词搜索'}
@@ -74,16 +76,16 @@ export default function SearchScreen() {
   };
 
   return (
-    <SafeAreaView style={styles.safe} edges={['top', 'left', 'right']}>
+    <SafeAreaView style={[styles.safe, { backgroundColor: theme.bg }]} edges={['top', 'left', 'right']}>
       {/* Search header */}
-      <View style={styles.header}>
+      <View style={[styles.header, { backgroundColor: theme.card, borderBottomColor: theme.border }]}>
         <TouchableOpacity onPress={() => router.back()} style={styles.backBtn}>
-          <Ionicons name="chevron-back" size={24} color="#212121" />
+          <Ionicons name="chevron-back" size={24} color={theme.text} />
         </TouchableOpacity>
-        <View style={styles.inputWrap}>
+        <View style={[styles.inputWrap, { backgroundColor: theme.inputBg }]}>
           <TextInput
             ref={inputRef}
-            style={styles.input}
+            style={[styles.input, { color: theme.text }]}
             placeholder="搜索视频、UP主..."
             placeholderTextColor="#999"
             value={keyword}
diff --git a/app/settings.tsx b/app/settings.tsx
index 12a4269..7377caf 100644
--- a/app/settings.tsx
+++ b/app/settings.tsx
@@ -5,12 +5,14 @@ import { useRouter } from 'expo-router';
 import { Ionicons } from '@expo/vector-icons';
 import { useAuthStore } from '../store/authStore';
 import { useSettingsStore } from '../store/settingsStore';
+import { useTheme } from '../utils/theme';
 import { useCheckUpdate } from '../hooks/useCheckUpdate';
 
 export default function SettingsScreen() {
   const router = useRouter();
   const { isLoggedIn, logout } = useAuthStore();
-  const { coverQuality, setCoverQuality } = useSettingsStore();
+  const { darkMode, setDarkMode, trafficSaving, setTrafficSaving } = useSettingsStore();
+  const theme = useTheme();
   const { currentVersion, isChecking, downloadProgress, checkUpdate } = useCheckUpdate();
 
   const handleLogout = async () => {
@@ -19,25 +21,25 @@ export default function SettingsScreen() {
   };
 
   return (
-    <SafeAreaView style={styles.safe}>
-      <View style={styles.topBar}>
+    <SafeAreaView style={[styles.safe, { backgroundColor: theme.bg }]}>
+      <View style={[styles.topBar, { backgroundColor: theme.card, borderBottomColor: theme.border }]}>
         <TouchableOpacity onPress={() => router.back()} style={styles.backBtn}>
-          <Ionicons name="chevron-back" size={24} color="#212121" />
+          <Ionicons name="chevron-back" size={24} color={theme.text} />
         </TouchableOpacity>
-        <Text style={styles.topTitle}>设置</Text>
+        <Text style={[styles.topTitle, { color: theme.text }]}>设置</Text>
         <View style={styles.spacer} />
       </View>
 
-      <View style={styles.section}>
-        <Text style={styles.sectionLabel}>版本信息</Text>
+      <View style={[styles.section, { backgroundColor: theme.card, borderColor: theme.border }]}>
+        <Text style={[styles.sectionLabel, { color: theme.textSub }]}>版本信息</Text>
         <View style={styles.versionRow}>
-          <Text style={styles.versionLabel}>当前版本</Text>
-          <Text style={styles.versionValue}>v{currentVersion}</Text>
+          <Text style={[styles.versionLabel, { color: theme.text }]}>当前版本</Text>
+          <Text style={[styles.versionValue, { color: theme.textSub }]}>v{currentVersion}</Text>
         </View>
       </View>
 
-      <View style={styles.section}>
-        <Text style={styles.sectionLabel}>更新</Text>
+      <View style={[styles.section, { backgroundColor: theme.card, borderColor: theme.border }]}>
+        <Text style={[styles.sectionLabel, { color: theme.textSub }]}>更新</Text>
         <TouchableOpacity
           style={styles.updateBtn}
           onPress={checkUpdate}
@@ -57,30 +59,51 @@ export default function SettingsScreen() {
         </TouchableOpacity>
       </View>
 
-      <View style={styles.section}>
-        <Text style={styles.sectionLabel}>封面图清晰度</Text>
+      <View style={[styles.section, { backgroundColor: theme.card, borderColor: theme.border }]}>
+        <Text style={[styles.sectionLabel, { color: theme.textSub }]}>外观</Text>
         <View style={styles.optionRow}>
           <TouchableOpacity
-            style={[styles.option, coverQuality === 'hd' && styles.optionActive]}
-            onPress={() => setCoverQuality('hd')}
+            style={[styles.option, !darkMode && styles.optionActive]}
+            onPress={() => setDarkMode(false)}
             activeOpacity={0.7}
           >
-            <Text style={[styles.optionText, coverQuality === 'hd' && styles.optionTextActive]}>
-              高清
-            </Text>
+            <Text style={[styles.optionText, !darkMode && styles.optionTextActive]}>浅色</Text>
           </TouchableOpacity>
           <TouchableOpacity
-            style={[styles.option, coverQuality === 'normal' && styles.optionActive]}
-            onPress={() => setCoverQuality('normal')}
+            style={[styles.option, darkMode && styles.optionActive]}
+            onPress={() => setDarkMode(true)}
             activeOpacity={0.7}
           >
-            <Text style={[styles.optionText, coverQuality === 'normal' && styles.optionTextActive]}>
-              普通
-            </Text>
+            <Text style={[styles.optionText, darkMode && styles.optionTextActive]}>深色</Text>
           </TouchableOpacity>
         </View>
       </View>
 
+      <View style={[styles.section, { backgroundColor: theme.card, borderColor: theme.border }]}>
+        <Text style={[styles.sectionLabel, { color: theme.textSub }]}>流量</Text>
+        <View style={styles.optionRow}>
+          <TouchableOpacity
+            style={[styles.option, !trafficSaving && styles.optionActive]}
+            onPress={() => setTrafficSaving(false)}
+            activeOpacity={0.7}
+          >
+            <Text style={[styles.optionText, !trafficSaving && styles.optionTextActive]}>标准</Text>
+          </TouchableOpacity>
+          <TouchableOpacity
+            style={[styles.option, trafficSaving && styles.optionActive]}
+            onPress={() => setTrafficSaving(true)}
+            activeOpacity={0.7}
+          >
+            <Text style={[styles.optionText, trafficSaving && styles.optionTextActive]}>节流</Text>
+          </TouchableOpacity>
+        </View>
+        {trafficSaving && (
+          <Text style={[styles.hint, { color: theme.textSub }]}>
+            封面低画质 · 首页视频不自动播放 · 视频默认 360p
+          </Text>
+        )}
+      </View>
+
       {isLoggedIn && (
         <TouchableOpacity style={styles.logoutBtn} onPress={handleLogout} activeOpacity={0.8}>
           <Text style={styles.logoutText}>退出登录</Text>
@@ -91,15 +114,13 @@ export default function SettingsScreen() {
 }
 
 const styles = StyleSheet.create({
-  safe: { flex: 1, backgroundColor: '#f4f4f4' },
+  safe: { flex: 1 },
   topBar: {
     flexDirection: 'row',
     alignItems: 'center',
     paddingHorizontal: 8,
     paddingVertical: 8,
-    backgroundColor: '#fff',
     borderBottomWidth: StyleSheet.hairlineWidth,
-    borderBottomColor: '#eee',
   },
   backBtn: { padding: 4, width: 32 },
   spacer: { width: 32 },
@@ -107,20 +128,16 @@ const styles = StyleSheet.create({
     flex: 1,
     fontSize: 16,
     fontWeight: '600',
-    color: '#212121',
     textAlign: 'center',
   },
   section: {
-    backgroundColor: '#fff',
     marginTop: 16,
     paddingHorizontal: 16,
     paddingVertical: 14,
     borderTopWidth: StyleSheet.hairlineWidth,
-    borderTopColor: '#eee',
     borderBottomWidth: StyleSheet.hairlineWidth,
-    borderBottomColor: '#eee',
   },
-  sectionLabel: { fontSize: 13, color: '#999', marginBottom: 10 },
+  sectionLabel: { fontSize: 13, marginBottom: 10 },
   optionRow: { flexDirection: 'row', gap: 10 },
   option: {
     paddingHorizontal: 20,
@@ -128,18 +145,19 @@ const styles = StyleSheet.create({
     borderRadius: 20,
     borderWidth: 1,
     borderColor: '#e0e0e0',
-    backgroundColor: '#fff',
+    backgroundColor: 'transparent',
   },
   optionActive: { borderColor: '#00AEEC', backgroundColor: '#e8f7fd' },
   optionText: { fontSize: 14, color: '#666' },
   optionTextActive: { color: '#00AEEC', fontWeight: '600' },
+  hint: { fontSize: 12, marginTop: 8 },
   versionRow: {
     flexDirection: 'row',
     justifyContent: 'space-between',
     alignItems: 'center',
   },
-  versionLabel: { fontSize: 14, color: '#212121' },
-  versionValue: { fontSize: 14, color: '#999' },
+  versionLabel: { fontSize: 14 },
+  versionValue: { fontSize: 14 },
   updateBtn: {
     flexDirection: 'row',
     alignItems: 'center',
@@ -150,7 +168,6 @@ const styles = StyleSheet.create({
     margin: 24,
     paddingVertical: 12,
     borderRadius: 8,
-    backgroundColor: '#fff',
     borderWidth: 1,
     borderColor: '#ff4757',
     alignItems: 'center',
diff --git a/components/BigVideoCard.tsx b/components/BigVideoCard.tsx
index d6956ff..4199f06 100644
--- a/components/BigVideoCard.tsx
+++ b/components/BigVideoCard.tsx
@@ -22,6 +22,7 @@ import { buildDashMpdUri } from "../utils/dash";
 import { getPlayUrl, getVideoDetail } from "../services/bilibili";
 import { coverImageUrl } from "../utils/imageUrl";
 import { useSettingsStore } from "../store/settingsStore";
+import { useTheme } from "../utils/theme";
 import { formatCount, formatDuration } from "../utils/format";
 import type { VideoItem } from "../services/types";
 
@@ -55,7 +56,8 @@ export const BigVideoCard = React.memo(function BigVideoCard({
   onPress,
 }: Props) {
   const { width: SCREEN_W } = useWindowDimensions();
-  const coverQuality = useSettingsStore(s => s.coverQuality);
+  const trafficSaving = useSettingsStore(s => s.trafficSaving);
+  const theme = useTheme();
   const THUMB_H = SCREEN_W * 0.5625;
   const mediaDimensions = { width: SCREEN_W - 8, height: THUMB_H };
 
@@ -90,7 +92,7 @@ export const BigVideoCard = React.memo(function BigVideoCard({
 
   // Preload: fetch play URL on mount (before card is visible)
   useEffect(() => {
-    if (videoUrl) return;
+    if (videoUrl || trafficSaving) return;
     let cancelled = false;
     (async () => {
       try {
@@ -125,8 +127,8 @@ export const BigVideoCard = React.memo(function BigVideoCard({
   // Pause/resume based on visibility and scroll state
   useEffect(() => {
     if (!videoUrl) return;
-    if (!isVisible) {
-      // Off-screen: pause, mute, show thumbnail
+    if (!isVisible || trafficSaving) {
+      // Off-screen or traffic saving: pause, mute, show thumbnail
       setPaused(true);
       setMuted(true);
       Animated.timing(thumbOpacity, {
@@ -146,10 +148,10 @@ export const BigVideoCard = React.memo(function BigVideoCard({
         useNativeDriver: true,
       }).start();
     }
-  }, [isVisible, isScrolling, videoUrl]);
+  }, [isVisible, isScrolling, videoUrl, trafficSaving]);
 
   const handleVideoReady = () => {
-    if (!isVisible || isScrolling) return;
+    if (!isVisible || isScrolling || trafficSaving) return;
     setPaused(false);
     Animated.timing(thumbOpacity, {
       toValue: 0,
@@ -223,7 +225,7 @@ export const BigVideoCard = React.memo(function BigVideoCard({
   const bufferedRatio = duration > 0 ? clamp(buffered / duration, 0, 1) : 0;
 
   return (
-    <View style={styles.card}>
+    <View style={[styles.card, { backgroundColor: theme.card }]}>
       {/* Media area */}
       <View style={[mediaDimensions, { position: "relative" }]}>
         {/* Video player — rendered first so it sits behind the thumbnail */}
@@ -260,7 +262,7 @@ export const BigVideoCard = React.memo(function BigVideoCard({
           pointerEvents="none"
         >
           <Image
-            source={{ uri: coverImageUrl(item.pic, coverQuality) }}
+            source={{ uri: coverImageUrl(item.pic, trafficSaving ? 'normal' : 'hd') }}
             style={mediaDimensions}
             resizeMode="cover"
           />
@@ -338,11 +340,11 @@ export const BigVideoCard = React.memo(function BigVideoCard({
       {/* Info */}
       <TouchableOpacity onPress={onPress} activeOpacity={0.85}>
         <View style={styles.info}>
-          <Text style={styles.title} numberOfLines={2}>
+          <Text style={[styles.title, { color: theme.text }]} numberOfLines={2}>
             {item.title}
           </Text>
 
-          <Text style={styles.owner} numberOfLines={1}>
+          <Text style={[styles.owner, { color: theme.textSub }]} numberOfLines={1}>
             {item.owner?.name ?? ""}
           </Text>
         </View>
diff --git a/components/LiveCard.tsx b/components/LiveCard.tsx
index ba335d7..6e24058 100644
--- a/components/LiveCard.tsx
+++ b/components/LiveCard.tsx
@@ -12,6 +12,7 @@ import { LivePulse } from "./LivePulse";
 import type { LiveRoom } from "../services/types";
 import { formatCount } from "../utils/format";
 import { proxyImageUrl } from "../utils/imageUrl";
+import { useTheme } from "../utils/theme";
 
 const { width } = Dimensions.get("window");
 const CARD_WIDTH = (width - 14) / 2;
@@ -30,9 +31,10 @@ export const LiveCard = React.memo(function LiveCard({
   isLivePulse = false,
 }: Props) {
   const cardWidth = fullWidth ? width - 8 : CARD_WIDTH;
+  const theme = useTheme();
   return (
     <TouchableOpacity
-      style={[styles.card, { width: cardWidth }]}
+      style={[styles.card, { width: cardWidth, backgroundColor: theme.card }]}
       onPress={onPress}
       activeOpacity={0.85}
     >
@@ -58,7 +60,7 @@ export const LiveCard = React.memo(function LiveCard({
         </View>
       </View>
       <View style={styles.info}>
-        <Text style={styles.title} numberOfLines={2}>
+        <Text style={[styles.title, { color: theme.text }]} numberOfLines={2}>
           {item.title}
         </Text>
         <View style={styles.ownerRow}>
@@ -66,7 +68,7 @@ export const LiveCard = React.memo(function LiveCard({
             source={{ uri: proxyImageUrl(item.face) }}
             style={styles.avatar}
           />
-          <Text style={styles.owner} numberOfLines={1}>
+          <Text style={[styles.owner, { color: theme.textSub }]} numberOfLines={1}>
             {item.uname}
           </Text>
         </View>
diff --git a/components/VideoCard.tsx b/components/VideoCard.tsx
index 7e7b999..153fd7d 100644
--- a/components/VideoCard.tsx
+++ b/components/VideoCard.tsx
@@ -12,6 +12,7 @@ import type { VideoItem } from "../services/types";
 import { formatCount, formatDuration } from "../utils/format";
 import { coverImageUrl } from "../utils/imageUrl";
 import { useSettingsStore } from "../store/settingsStore";
+import { useTheme } from "../utils/theme";
 
 const { width } = Dimensions.get("window");
 const CARD_WIDTH = (width - 14) / 2;
@@ -22,16 +23,17 @@ interface Props {
 }
 
 export const VideoCard = React.memo(function VideoCard({ item, onPress }: Props) {
-  const coverQuality = useSettingsStore(s => s.coverQuality);
+  const trafficSaving = useSettingsStore(s => s.trafficSaving);
+  const theme = useTheme();
   return (
     <TouchableOpacity
-      style={styles.card}
+      style={[styles.card, { backgroundColor: theme.card }]}
       onPress={onPress}
       activeOpacity={0.85}
     >
       <View style={styles.thumbContainer}>
         <Image
-          source={{ uri: coverImageUrl(item.pic, coverQuality) }}
+          source={{ uri: coverImageUrl(item.pic, trafficSaving ? 'normal' : 'hd') }}
           style={styles.thumb}
           resizeMode="cover"
         />
@@ -48,10 +50,10 @@ export const VideoCard = React.memo(function VideoCard({ item, onPress }: Props)
         </View>
       </View>
       <View style={styles.info}>
-        <Text style={styles.title} numberOfLines={2}>
+        <Text style={[styles.title, { color: theme.text }]} numberOfLines={2}>
           {item.title}
         </Text>
-        <Text style={styles.owner} numberOfLines={1}>
+        <Text style={[styles.owner, { color: theme.textSub }]} numberOfLines={1}>
           {item.owner?.name ?? ""}
         </Text>
       </View>
diff --git a/hooks/useVideoDetail.ts b/hooks/useVideoDetail.ts
index 7bf0386..e0075b9 100644
--- a/hooks/useVideoDetail.ts
+++ b/hooks/useVideoDetail.ts
@@ -1,6 +1,7 @@
 import { useState, useEffect, useRef } from 'react';
 import { getVideoDetail, getPlayUrl } from '../services/bilibili';
 import { useAuthStore } from '../store/authStore';
+import { useSettingsStore } from '../store/settingsStore';
 import type { VideoItem, PlayUrlResponse } from '../services/types';
 
 export function useVideoDetail(bvid: string) {
@@ -12,6 +13,8 @@ export function useVideoDetail(bvid: string) {
   const [error, setError] = useState<string | null>(null);
   const cidRef = useRef<number>(0);
   const isLoggedIn = useAuthStore(s => s.isLoggedIn);
+  const trafficSaving = useSettingsStore(s => s.trafficSaving);
+  const defaultQn = trafficSaving ? 16 : 126;
 
   async function fetchPlayData(cid: number, qn: number, updateList = false) {
     const data = await getPlayUrl(bvid, cid, qn);
@@ -39,7 +42,7 @@ export function useVideoDetail(bvid: string) {
         setVideo(detail);
         const cid = detail.pages?.[0]?.cid ?? detail.cid as number;
         cidRef.current = cid;
-        await fetchPlayData(cid, 126, true);
+        await fetchPlayData(cid, defaultQn, true);
       } catch (e: any) {
         setError(e.message ?? 'Load failed');
       } finally {
@@ -52,7 +55,7 @@ export function useVideoDetail(bvid: string) {
   // 登录状态变化时重新拉取清晰度列表（登录后可能获得更高画质）
   useEffect(() => {
     if (cidRef.current) {
-      fetchPlayData(cidRef.current, 126, true).catch((e) => {
+      fetchPlayData(cidRef.current, defaultQn, true).catch((e) => {
         console.warn('Failed to refresh quality list after login change:', e);
       });
     }
diff --git a/store/settingsStore.ts b/store/settingsStore.ts
index b8c4f64..39ab39a 100644
--- a/store/settingsStore.ts
+++ b/store/settingsStore.ts
@@ -2,21 +2,35 @@ import { create } from 'zustand';
 import AsyncStorage from '@react-native-async-storage/async-storage';
 
 interface SettingsState {
-  coverQuality: 'hd' | 'normal';
-  setCoverQuality: (q: 'hd' | 'normal') => Promise<void>;
+  darkMode: boolean;
+  trafficSaving: boolean;
+  setDarkMode: (v: boolean) => Promise<void>;
+  setTrafficSaving: (v: boolean) => Promise<void>;
   restore: () => Promise<void>;
 }
 
 export const useSettingsStore = create<SettingsState>((set) => ({
-  coverQuality: 'hd',
+  darkMode: false,
+  trafficSaving: false,
 
-  setCoverQuality: async (q) => {
-    await AsyncStorage.setItem('COVER_QUALITY', q);
-    set({ coverQuality: q });
+  setDarkMode: async (v) => {
+    await AsyncStorage.setItem('DARK_MODE', v ? '1' : '0');
+    set({ darkMode: v });
+  },
+
+  setTrafficSaving: async (v) => {
+    await AsyncStorage.setItem('TRAFFIC_SAVING', v ? '1' : '0');
+    set({ trafficSaving: v });
   },
 
   restore: async () => {
-    const q = await AsyncStorage.getItem('COVER_QUALITY');
-    if (q === 'hd' || q === 'normal') set({ coverQuality: q });
+    const [dm, ts] = await Promise.all([
+      AsyncStorage.getItem('DARK_MODE'),
+      AsyncStorage.getItem('TRAFFIC_SAVING'),
+    ]);
+    set({
+      darkMode: dm === '1',
+      trafficSaving: ts === '1',
+    });
   },
 }));
diff --git a/utils/theme.ts b/utils/theme.ts
new file mode 100644
index 0000000..7265ef5
--- /dev/null
+++ b/utils/theme.ts
@@ -0,0 +1,33 @@
+import { useSettingsStore } from '../store/settingsStore';
+
+export type ThemeColors = {
+  bg: string;       // 页面/列表背景
+  card: string;     // 卡片/section 背景
+  text: string;     // 主文字
+  textSub: string;  // 次要文字
+  border: string;   // 分割线
+  inputBg: string;  // 输入框背景
+};
+
+const light: ThemeColors = {
+  bg: '#f4f4f4',
+  card: '#fff',
+  text: '#212121',
+  textSub: '#999',
+  border: '#eee',
+  inputBg: '#f0f0f0',
+};
+
+const dark: ThemeColors = {
+  bg: '#0f0f0f',
+  card: '#1a1a1a',
+  text: '#e0e0e0',
+  textSub: '#666',
+  border: '#2a2a2a',
+  inputBg: '#2a2a2a',
+};
+
+export function useTheme(): ThemeColors {
+  const darkMode = useSettingsStore(s => s.darkMode);
+  return darkMode ? dark : light;
+}