diff --git a/assets/scripts/AppBootstrap.ts b/assets/scripts/AppBootstrap.ts
index 53fbe2e..33ff456 100644
--- a/assets/scripts/AppBootstrap.ts
+++ b/assets/scripts/AppBootstrap.ts
@@ -7,12 +7,8 @@ import { ViewController } from './controller/ViewController';
 import { LineGridRenderer } from './gameplay/LineGridRenderer';
 import { UIMain } from './ui/UIMain';
 import { loadLevelDatabase, refreshLevelIdBounds, LEVEL_ID_BASE } from './level/LevelRegistry';
-import { loadThemeDatabase } from './theme/ThemeRegistry';
-import { ensureResourcesBundle } from './core/ResourcesBundle';
-import { loadTileDisplayMeta } from './visual/TileDisplayMeta';
 import { ThemeBackground } from './theme/ThemeBackground';
 import { GridSnapHelper } from './level/GridSnapHelper';
-import { GameAudio } from './audio/GameAudio';
 import { GameplayDebugBar } from './ui/GameplayDebugBar';
 import {
     CELL_PIXEL, CAMERA_ORTHO_HALF, DESIGN_WIDTH, DESIGN_HEIGHT,
@@ -55,12 +51,8 @@ export class AppBootstrap extends Component {
         console.log('[AppBootstrap] 开始初始化…');
         applyEmbeddedDesignResolution();
         view.on('canvas-resize', this.onCanvasResize, this);
-        await ensureResourcesBundle();
-        await loadThemeDatabase();
-        await loadTileDisplayMeta();
         await loadLevelDatabase();
         refreshLevelIdBounds();
-        await GameAudio.preload();
 
         const scene = director.getScene()!;
         find('UICanvas', scene)?.destroy();
@@ -108,7 +100,7 @@ export class AppBootstrap extends Component {
         // 关卡预制体由 SwitchLevel → createNewLevel 按需加载（loader 进关再下 levels_all）
         ctl.markReady();
         ctl.onBootstrapReady();
-        console.log('[AppBootstrap] 引擎已就绪；SwitchLevel 进关时再加载关卡预制体');
+        console.log('[AppBootstrap] 引擎已就绪；SwitchLevel 进关时再加载资源/关卡库分片/预制体');
     }
 
     private ensureGameRoot(scene: Node, size: { width: number; height: number }, mainCam: Camera): Node {
diff --git a/assets/scripts/GameController.ts b/assets/scripts/GameController.ts
index dfcfb5a..517e5b1 100644
--- a/assets/scripts/GameController.ts
+++ b/assets/scripts/GameController.ts
@@ -14,6 +14,7 @@ import {
 } from './core/Define';
 import { EventManager, EventType } from './core/EventManager';
 import { ExternalLevelInfo, JsBridge } from './bridge/JsBridge';
+import { ensureRuntimeAssetsForLevel } from './core/RuntimePack';
 import {
     hasLevel, getMaxLevelId, getMinLevelId, LEVEL_ID_BASE, resolveLevelConfig,
     nextLevelId, prevLevelId,
@@ -25,7 +26,7 @@ import {
 } from './level/EntitySpawnPlacement';
 import { EntityVisualOptions } from './visual/EntityTextureResolver';
 import { getLevelPrefabResourcePath } from './level/LevelPrefabPaths';
-import { loadLevelPrefab } from './level/LevelPrefabLoader';
+import { loadLevelPrefab as loadLevelPrefabImpl } from './level/LevelPrefabLoader';
 import { PlayerController } from './controller/PlayerController';
 import { VehicleController } from './controller/VehicleController';
 import { PropController } from './controller/PropController';
@@ -52,6 +53,13 @@ interface GridEntry {
     node: Node;
 }
 
+/** Web 主站：优先走 loader 注入的 loadLevelPrefab（按关下载 + 内存 bundle） */
+function loadLevelPrefabForRuntime(path: string) {
+    const hook = (globalThis as { __tfrhLoadLevelPrefab?: typeof loadLevelPrefabImpl }).__tfrhLoadLevelPrefab;
+    if (typeof hook === 'function') return hook(path);
+    return loadLevelPrefabImpl(path);
+}
+
 /**
  * 主站唯一入口组件（原 GameManager + GameController 合并）。
  * Inspector：填写 inputLevel，预览 ▶ 后点 SwitchLevel（对齐 Unity TestGame2）。
@@ -793,6 +801,13 @@ export class GameController extends Component {
     async createNewLevel(levelID: number) {
         if (this.creating) return;
         this.creating = true;
+        try {
+            await ensureRuntimeAssetsForLevel(levelID);
+        } catch (e) {
+            console.error('[GameController] 运行时资源加载失败', e);
+            this.creating = false;
+            return;
+        }
         const config = resolveLevelConfig(levelID);
         if (!config || !this.mainLevelEntrance) {
             this.creating = false;
@@ -809,7 +824,7 @@ export class GameController extends Component {
 
         const path = getLevelPrefabResourcePath(levelID, config);
         try {
-            const prefab = await loadLevelPrefab(path);
+            const prefab = await loadLevelPrefabForRuntime(path);
             await VisualAssets.preload(this.uiStyle);
             // 在 instantiate 前无法拦截；先禁用 prefab 内 GridSnapHelper 的 showGrid
             GridSnapHelper.stripBeforePlayFromPrefab(prefab);
diff --git a/assets/scripts/core/RuntimePack.ts b/assets/scripts/core/RuntimePack.ts
new file mode 100644
index 0000000..c9e5f14
--- /dev/null
+++ b/assets/scripts/core/RuntimePack.ts
@@ -0,0 +1,40 @@
+/**
+ * 进关前按需加载：assets_all、主题/贴图元数据、关卡库分片。
+ * 由 loader 注入 __tfrhEnsureAssetsCore / __tfrhEnsureLevelDbShard。
+ */
+import { ensureResourcesBundle } from './ResourcesBundle';
+import { loadThemeDatabase } from '../theme/ThemeRegistry';
+import { loadTileDisplayMeta } from '../visual/TileDisplayMeta';
+import { ensureLevelShardLoaded } from '../level/LevelDatabase';
+
+declare global {
+    interface Window {
+        __tfrhEnsureAssetsCore?: (onProgress?: (frac: number) => void) => Promise<void>;
+        __tfrhEnsureLevelDbShard?: (levelId: number) => Promise<void>;
+        __tfrhEnsureLevelPack?: (levelId: number) => Promise<void>;
+    }
+}
+
+let runtimePrimed = false;
+
+/** 首关 SwitchLevel 前拉齐运行时依赖（bootstrap 不再预载） */
+export async function ensureRuntimeAssetsForLevel(levelId: number): Promise<void> {
+    if (typeof window !== 'undefined') {
+        if (window.__tfrhEnsureAssetsCore) {
+            await window.__tfrhEnsureAssetsCore();
+        }
+        if (window.__tfrhEnsureLevelDbShard) {
+            await window.__tfrhEnsureLevelDbShard(levelId);
+        }
+        if (window.__tfrhEnsureLevelPack) {
+            await window.__tfrhEnsureLevelPack(levelId);
+        }
+    }
+    await ensureResourcesBundle();
+    if (!runtimePrimed) {
+        await loadThemeDatabase();
+        await loadTileDisplayMeta();
+        runtimePrimed = true;
+    }
+    await ensureLevelShardLoaded(levelId);
+}
diff --git a/assets/scripts/core/RuntimePack.ts.meta b/assets/scripts/core/RuntimePack.ts.meta
new file mode 100644
index 0000000..e4e1ef9
--- /dev/null
+++ b/assets/scripts/core/RuntimePack.ts.meta
@@ -0,0 +1,9 @@
+{
+  "ver": "4.0.24",
+  "importer": "typescript",
+  "imported": true,
+  "uuid": "2de0b14b-7d3b-4ac4-963c-f7b352db60c9",
+  "files": [],
+  "subMetas": {},
+  "userData": {}
+}
diff --git a/assets/scripts/level/LevelDatabase.ts b/assets/scripts/level/LevelDatabase.ts
index c6cd21a..07eb664 100644
--- a/assets/scripts/level/LevelDatabase.ts
+++ b/assets/scripts/level/LevelDatabase.ts
@@ -21,19 +21,41 @@ export interface LevelDatabaseFile {
     levels: Record<string, LevelConfig>;
 }
 
+export interface LevelsDbIndex {
+    version: number;
+    mode: 'sharded';
+    shardSize?: number;
+    levelIdBase?: number;
+    generatedAt?: string;
+    source?: string;
+    total: number;
+    min: number;
+    max: number;
+    stats?: LevelDatabaseFile['stats'];
+    shards: Array<{ min: number; max: number; file: string; count?: number }>;
+}
+
 declare global {
     interface Window {
         /** 主站 scratch-gui 注入：/unity/levels-database.json */
         __tfrhLevelsDatabaseUrl?: string;
-        /** loader 预注入的 JSON（可选） */
+        /** loader 预注入的 JSON（可选，legacy 全量） */
         __tfrhLevelsDatabaseJson?: LevelDatabaseFile;
+        /** 分片索引 URL / 预注入 */
+        __tfrhLevelsDbIndexUrl?: string;
+        __tfrhLevelsDbIndex?: LevelsDbIndex;
+        /** loader 按关拉取分片 */
+        __tfrhEnsureLevelDbShard?: (levelId: number) => Promise<void>;
     }
 }
 
 let fileCache: LevelDatabaseFile | null = null;
+let indexCache: LevelsDbIndex | null = null;
 let levelsMap: Record<number, LevelConfig> = {};
 let sortedIds: number[] = [];
 let loadPromise: Promise<void> | null = null;
+const loadedShardKeys = new Set<string>();
+const shardLoadPromises = new Map<string, Promise<void>>();
 
 function rebuildIndex() {
     sortedIds = Object.keys(levelsMap)
@@ -42,18 +64,62 @@ function rebuildIndex() {
         .sort((a, b) => a - b);
 }
 
-function ingestFile(data: LevelDatabaseFile) {
-    fileCache = data;
-    levelsMap = {};
+function ingestFile(data: LevelDatabaseFile, merge = false) {
+    if (!merge) {
+        fileCache = data;
+        levelsMap = {};
+    } else if (!fileCache) {
+        fileCache = {
+            version: data.version || 1,
+            levels: {},
+        };
+    }
     for (const [k, cfg] of Object.entries(data.levels ?? {})) {
         const id = parseInt(k, 10);
         if (!Number.isNaN(id)) {
             levelsMap[id] = { ...cfg, levelID: id };
+            if (fileCache?.levels) {
+                fileCache.levels[String(id)] = levelsMap[id];
+            }
         }
     }
     rebuildIndex();
 }
 
+function ingestIndex(data: LevelsDbIndex) {
+    indexCache = data;
+    if (!fileCache) {
+        fileCache = {
+            version: data.version,
+            generatedAt: data.generatedAt,
+            source: data.source,
+            levelIdBase: data.levelIdBase,
+            stats: data.stats,
+            levels: {},
+        };
+    }
+}
+
+function findShardForLevel(levelId: number): LevelsDbIndex['shards'][0] | null {
+    if (!indexCache?.shards?.length) return null;
+    for (const shard of indexCache.shards) {
+        if (levelId >= shard.min && levelId <= shard.max) return shard;
+    }
+    return null;
+}
+
+function shardKey(shard: { file: string }) {
+    return shard.file;
+}
+
+function validateIndex(index: LevelsDbIndex): void {
+    if (index.total < 100 || index.min < LEVEL_ID_BASE) {
+        throw new Error(
+            `关卡库索引过旧 (${index.total} 关)，请重新 package-for-project`,
+        );
+    }
+}
+
 function resolveRemoteUrl(): string | null {
     if (typeof window === 'undefined') return null;
     const url = window.__tfrhLevelsDatabaseUrl;
@@ -61,6 +127,10 @@ function resolveRemoteUrl(): string | null {
 }
 
 function validateIngested(): void {
+    if (indexCache) {
+        validateIndex(indexCache);
+        return;
+    }
     const total = sortedIds.length;
     const minId = sortedIds[0] ?? 0;
     if (total < 100 || minId < LEVEL_ID_BASE) {
@@ -90,6 +160,139 @@ function fetchCandidates(): string[] {
     return [...new Set(out)];
 }
 
+function indexFetchCandidates(): string[] {
+    const out: string[] = [];
+    if (typeof window !== 'undefined') {
+        const configured = window.__tfrhLevelsDbIndexUrl?.trim();
+        if (configured && /^https?:\/\//i.test(configured)) {
+            out.push(configured);
+        }
+    }
+    if (canUseHttpFetch()) {
+        out.push(new URL('levels-db-index.json', window.location.href).href);
+        out.push(new URL('/unity/levels-db-index.json', window.location.origin).href);
+    }
+    return [...new Set(out)];
+}
+
+async function fetchJsonWithBrotli(url: string): Promise<unknown> {
+    const brUrl = url.replace(/\.json(\?.*)?$/i, '.json.br$1');
+    try {
+        const brRes = await fetch(brUrl);
+        if (brRes.ok && typeof DecompressionStream !== 'undefined') {
+            const text = await new Response(await brRes.arrayBuffer())
+                .pipeThrough(new DecompressionStream('brotli'))
+                .text();
+            return JSON.parse(text);
+        }
+    } catch {
+        /* fallback */
+    }
+    const res = await fetch(url, { credentials: 'same-origin' });
+    if (!res.ok) throw new Error(`HTTP ${res.status} for ${url}`);
+    return res.json();
+}
+
+async function loadIndexFromNetwork(): Promise<void> {
+    const candidates = indexFetchCandidates();
+    if (!candidates.length) {
+        throw new Error('[LevelDatabase] 无法 fetch 关卡库索引');
+    }
+    const errors: unknown[] = [];
+    for (const url of candidates) {
+        try {
+            const json = await fetchJsonWithBrotli(url) as LevelsDbIndex;
+            if (json?.mode !== 'sharded' || !json.shards?.length) {
+                throw new Error('非分片索引');
+            }
+            ingestIndex(json);
+            validateIngested();
+            console.log(
+                `[LevelDatabase] 已加载索引 ${json.total} 关 (${json.min}–${json.max})`,
+                url,
+            );
+            return;
+        } catch (e) {
+            errors.push(e);
+        }
+    }
+    throw new Error(
+        `[LevelDatabase] 无法加载关卡库索引: ${candidates.join(', ')}; `
+        + errors.map((e) => String(e)).join('; '),
+    );
+}
+
+function resolveShardUrl(shardFile: string): string {
+    const rel = shardFile.replace(/^\/+/, '');
+    if (canUseHttpFetch()) {
+        return new URL(`/unity/StreamingAssets/aa/${rel}`, window.location.origin).href;
+    }
+    return rel;
+}
+
+async function loadShardFromNetwork(shard: LevelsDbIndex['shards'][0]): Promise<void> {
+    const rel = shard.file.replace(/^\/+/, '');
+    const url = resolveShardUrl(rel);
+    const json = await fetchJsonWithBrotli(url) as LevelDatabaseFile;
+    ingestFile(json, true);
+    console.log(
+        `[LevelDatabase] 已加载分片 ${shard.min}–${shard.max} (+${Object.keys(json.levels ?? {}).length} 关)`,
+    );
+}
+
+async function loadShardNow(shard: LevelsDbIndex['shards'][0]): Promise<void> {
+    const key = shardKey(shard);
+    if (loadedShardKeys.has(key)) return;
+    const pending = shardLoadPromises.get(key);
+    if (pending) {
+        await pending;
+        return;
+    }
+    const promise = (async () => {
+        if (typeof window !== 'undefined' && window.__tfrhEnsureLevelDbShard) {
+            await window.__tfrhEnsureLevelDbShard(shard.min);
+            const json = window.__tfrhLevelsDatabaseJson;
+            if (json?.levels) {
+                const partial: LevelDatabaseFile = { version: json.version || 2, levels: {} };
+                for (const [k, cfg] of Object.entries(json.levels)) {
+                    const id = parseInt(k, 10);
+                    if (!Number.isNaN(id) && id >= shard.min && id <= shard.max) {
+                        partial.levels[k] = cfg;
+                    }
+                }
+                if (Object.keys(partial.levels).length) {
+                    ingestFile(partial, true);
+                    loadedShardKeys.add(key);
+                    console.log(
+                        `[LevelDatabase] 已合并分片 ${shard.min}–${shard.max} (+${Object.keys(partial.levels).length} 关)`,
+                    );
+                    return;
+                }
+            }
+        }
+        await loadShardFromNetwork(shard);
+        loadedShardKeys.add(key);
+    })();
+    shardLoadPromises.set(key, promise);
+    try {
+        await promise;
+    } finally {
+        shardLoadPromises.delete(key);
+    }
+}
+
+/** 进关前确保该关所在分片已加载 */
+export async function ensureLevelShardLoaded(levelId: number): Promise<void> {
+    if (!indexCache) return;
+    if (levelId in levelsMap) return;
+    const shard = findShardForLevel(levelId);
+    if (!shard) {
+        console.warn(`[LevelDatabase] 关卡 ${levelId} 不在索引范围`);
+        return;
+    }
+    await loadShardNow(shard);
+}
+
 function loadFromRemote(url: string): Promise<void> {
     const abs = /^https?:\/\//i.test(url)
         ? url
@@ -161,12 +364,19 @@ async function waitForInjection(maxMs = 2500): Promise<LevelDatabaseFile | null>
     return null;
 }
 
-/** 异步加载（AppBootstrap 启动时调用） */
+/** 异步加载（AppBootstrap 启动时调用；分片模式仅拉 index） */
 export function loadLevelDatabase(): Promise<void> {
-    if (fileCache) return Promise.resolve();
+    if (fileCache || indexCache) return Promise.resolve();
     if (loadPromise) return loadPromise;
     loadPromise = (async () => {
         try {
+            if (typeof window !== 'undefined' && window.__tfrhLevelsDbIndex) {
+                ingestIndex(window.__tfrhLevelsDbIndex);
+                validateIngested();
+                console.log(`[LevelDatabase] 已注入索引 ${indexCache!.total} 关`);
+                return;
+            }
+
             if (typeof window !== 'undefined' && window.__tfrhLevelsDatabaseJson) {
                 ingestFile(window.__tfrhLevelsDatabaseJson);
                 validateIngested();
@@ -196,6 +406,13 @@ export function loadLevelDatabase(): Promise<void> {
                 }
             }
 
+            try {
+                await loadIndexFromNetwork();
+                return;
+            } catch (e) {
+                console.warn('[LevelDatabase] 分片索引不可用，回退全量库', e);
+            }
+
             await loadFromNetwork();
         } catch (e) {
             loadPromise = null;
@@ -206,7 +423,11 @@ export function loadLevelDatabase(): Promise<void> {
 }
 
 export function isLevelDatabaseReady(): boolean {
-    return fileCache !== null;
+    return fileCache !== null || indexCache !== null;
+}
+
+export function isLevelDatabaseSharded(): boolean {
+    return indexCache !== null;
 }
 
 // --- 查 ---
@@ -216,7 +437,11 @@ export function getLevelConfig(levelID: number): LevelConfig | null {
 
 /** 是否在 Cocos 导出的关卡库中 */
 export function hasLevel(levelID: number): boolean {
-    return levelID in levelsMap;
+    if (levelID in levelsMap) return true;
+    if (indexCache && levelID >= indexCache.min && levelID <= indexCache.max) {
+        return true;
+    }
+    return false;
 }
 
 export function getLevelIds(): number[] {
@@ -227,19 +452,32 @@ export function getLevelCount(): number {
     return sortedIds.length;
 }
 
-export const MIN_LEVEL_ID = (): number => sortedIds[0] ?? LEVEL_ID_BASE;
-export const MAX_LEVEL_ID = (): number => sortedIds[sortedIds.length - 1] ?? LEVEL_ID_BASE;
+export const MIN_LEVEL_ID = (): number => indexCache?.min ?? sortedIds[0] ?? LEVEL_ID_BASE;
+export const MAX_LEVEL_ID = (): number => indexCache?.max ?? sortedIds[sortedIds.length - 1] ?? LEVEL_ID_BASE;
 
 export function nextLevelId(cur: number): number {
-    const i = sortedIds.indexOf(cur);
-    if (i < 0) return sortedIds[0] ?? cur;
-    return sortedIds[(i + 1) % sortedIds.length];
+    if (sortedIds.length) {
+        const i = sortedIds.indexOf(cur);
+        if (i < 0) return sortedIds[0] ?? cur;
+        return sortedIds[(i + 1) % sortedIds.length];
+    }
+    const max = MAX_LEVEL_ID();
+    const min = MIN_LEVEL_ID();
+    if (cur < min) return min;
+    if (cur >= max) return min;
+    return cur + 1;
 }
 
 export function prevLevelId(cur: number): number {
-    const i = sortedIds.indexOf(cur);
-    if (i < 0) return sortedIds[0] ?? cur;
-    return sortedIds[(i - 1 + sortedIds.length) % sortedIds.length];
+    if (sortedIds.length) {
+        const i = sortedIds.indexOf(cur);
+        if (i < 0) return sortedIds[0] ?? cur;
+        return sortedIds[(i - 1 + sortedIds.length) % sortedIds.length];
+    }
+    const max = MAX_LEVEL_ID();
+    const min = MIN_LEVEL_ID();
+    if (cur <= min) return max;
+    return cur - 1;
 }
 
 // --- 增改（运行时 / 编辑器脚本） ---
diff --git a/tools/package-for-cdn.js b/tools/package-for-cdn.js
index c081f11..ffde82b 100644
--- a/tools/package-for-cdn.js
+++ b/tools/package-for-cdn.js
@@ -12,13 +12,16 @@ const zlib = require('zlib');
 const { execSync } = require('child_process');
 const {
   patchPreloadSettings,
+  patchSplashSettings,
   printPackageReport,
   minifyLevelsDatabase,
   brotliCompressFile,
+  brotliCompressWebglBundles,
   formatBytes,
 } = require('./package-optimize');
 const { listRuntimeFiles, assertRuntimePack } = require('./runtime-pack');
 const { splitLevelBundles } = require('./split-level-bundles');
+const { splitLevelsDatabase } = require('./split-levels-database');
 
 const buildDir = path.resolve(process.argv[2]);
 const outDir = path.resolve(process.argv[3]);
@@ -83,9 +86,11 @@ function attachLevelsDatabase(outDir) {
     console.warn('>>> 警告: 未找到 levels-database.json');
     return;
   }
+  splitLevelsDatabase(levelsDbSrc, outDir);
+
   const levelsDbDst = path.join(outDir, 'levels-database.json');
   const { before, after } = minifyLevelsDatabase(levelsDbSrc, levelsDbDst);
-  console.log(`>>> levels-database.json 压缩: ${formatBytes(before)} → ${formatBytes(after)}`);
+  console.log(`>>> levels-database.json (legacy 回退): ${formatBytes(before)} → ${formatBytes(after)}`);
   const { raw, br } = brotliCompressFile(levelsDbDst, path.join(outDir, 'levels-database.json.br'));
   console.log(`>>> levels-database.json.br: ${formatBytes(raw)} → ${formatBytes(br)}`);
 }
@@ -139,6 +144,56 @@ function patchMainIndexForSplitLoad(mainIndexPath) {
   }
   let s = fs.readFileSync(mainIndexPath, 'utf8');
   const rules = [
+    {
+      desc: 'AppBootstrap: 首屏只 loadLevelDatabase + bounds',
+      old: 'yield I(),yield _(),yield E(),yield A(),L(),yield D.preload();',
+      neu: 'yield A(),L();',
+    },
+    {
+      desc: 'GameController: 进关前按需拉 assets / 关卡库分片',
+      old: 'if(!this.creating){this.creating=!0;var t=R(e);',
+      neu: 'if(!this.creating){this.creating=!0;try{if(globalThis.__tfrhEnsureAssetsCore)yield globalThis.__tfrhEnsureAssetsCore();yield I(),yield _(),yield E();if(globalThis.__tfrhEnsureLevelDbShard)yield globalThis.__tfrhEnsureLevelDbShard(e);}catch(err){console.error("[GameController] 运行时资源加载失败",err),this.creating=!1;return}var t=R(e);',
+    },
+    {
+      desc: 'LevelDatabase: 分片索引模式 isReady',
+      old: 'isLevelDatabaseReady:function(){return null!==s}',
+      neu: 'isLevelDatabaseReady:function(){return null!==s||("undefined"!=typeof window&&!!window.__tfrhLevelsDbIndex)}',
+    },
+    {
+      desc: 'LevelDatabase: 启动读 index 而非全量库',
+      old: 'try{if("undefined"!=typeof window&&window.__tfrhLevelsDatabaseJson)',
+      neu: 'try{if("undefined"!=typeof window&&window.__tfrhLevelsDbIndex){s={version:window.__tfrhLevelsDbIndex.version||2,levels:{}},console.log("[LevelDatabase] 已加载索引 "+window.__tfrhLevelsDbIndex.total+" 关");return}if("undefined"!=typeof window&&window.__tfrhLevelsDatabaseJson)',
+    },
+    {
+      desc: 'LevelDatabase: validate 接受 index',
+      old: 'function w(){var e=c.length,n=null!=(t=c[0])?t:0;if(e<100||n<a)throw new Error',
+      neu: 'function w(){if("undefined"!=typeof window&&window.__tfrhLevelsDbIndex){var e=window.__tfrhLevelsDbIndex;if(e.total<100||e.min<a)throw new Error("关卡库索引过旧 ("+e.total+" 关)");return}var e=c.length,n=null!=(t=c[0])?t:0;if(e<100||n<a)throw new Error',
+    },
+    {
+      desc: 'LevelRegistry: min/max 读 index',
+      old: 'function f(){return c()?d():t}function E(){return c()?I():t}',
+      neu: 'function f(){var e="undefined"!=typeof window&&window.__tfrhLevelsDbIndex;return e?e.min:c()?d():t}function E(){var e="undefined"!=typeof window&&window.__tfrhLevelsDbIndex;return e?e.max:c()?I():t}',
+    },
+    {
+      desc: 'LevelRegistry: hasLevel 读 index 范围',
+      old: 'hasLevel:function(e){return v(e)}',
+      neu: 'hasLevel:function(e){if(v(e))return!0;var n="undefined"!=typeof window&&window.__tfrhLevelsDbIndex;return!!n&&e>=n.min&&e<=n.max}',
+    },
+    {
+      desc: 'LevelDatabase: getLevelConfig 读 loader 分片',
+      old: 'getLevelConfig:function(e){var n;return null!=(n=f[e])?n:null}',
+      neu: 'getLevelConfig:function(e){var n;if(null!=(n=f[e]))return n;var t="undefined"!=typeof window&&window.__tfrhLevelsDatabaseJson&&window.__tfrhLevelsDatabaseJson.levels;return t&&t[String(e)]||null}',
+    },
+    {
+      desc: 'GameController: 使用 loader 全局 loadLevelPrefab hook (新构建 K)',
+      old: 'var l,r=yield K(i);',
+      neu: 'var l,r=yield(globalThis.__tfrhLoadLevelPrefab||K)(i);',
+    },
+    {
+      desc: 'GameController: 使用 loader 全局 loadLevelPrefab hook (旧构建 z)',
+      old: 'var l,r=yield z(i);',
+      neu: 'var l,r=yield(globalThis.__tfrhLoadLevelPrefab||z)(i);',
+    },
     {
       desc: 'AppBootstrap: 首关前不 preload UI 贴图',
       old: 'yield h.preload(),yield O.preload()',
@@ -256,10 +311,14 @@ patchText(path.join(scenesStage, 'src', 'settings.json'), (t) => {
   j.assets = j.assets || {};
   j.assets.server = '';
   patchPreloadSettings(j, { preloadResources: false, preloadLevelPrefabs: false });
+  patchSplashSettings(j, { stripSplashAssets: true });
   return JSON.stringify(j);
 });
 
 zipDir(scenesStage, path.join(webglDir, BUNDLE.scenesAll));
+const scenesZip = path.join(webglDir, BUNDLE.scenesAll);
+const scenesBr = brotliCompressFile(scenesZip, scenesZip + '.br');
+console.log(`>>> ${BUNDLE.scenesAll}.br: ${formatBytes(scenesBr.raw)} → ${formatBytes(scenesBr.br)}`);
 
 // —— 3a. assets_all：核心资源（不含 level-prefabs）——
 //     默认分包；MERGE_LEVELS=1 时合并 level-prefabs 进 assets_all（不推荐）
@@ -299,6 +358,8 @@ if (fs.existsSync(path.join(scenesStage, 'src', 'effect.bin'))) {
 const assetsCoreZip = path.join(webglDir, BUNDLE.assetsAll);
 zipDir(assetsCoreStage, assetsCoreZip);
 console.log(`>>> assets_core (assets_all): ${formatBytes(fs.statSync(assetsCoreZip).size)}`);
+const assetsBr = brotliCompressFile(assetsCoreZip, assetsCoreZip + '.br');
+console.log(`>>> ${BUNDLE.assetsAll}.br: ${formatBytes(assetsBr.raw)} → ${formatBytes(assetsBr.br)}`);
 
 // —— 3b. 每关独立 bundle + levels-manifest.json ——
 const levelPrefabsSrc = path.join(buildDir, 'assets', 'level-prefabs');
@@ -312,6 +373,8 @@ if (!MERGE_LEVELS) {
   patchCatalogRemoveLevelsBundle(path.join(aaDir, 'catalog.json'));
   const manifestPath = path.join(aaDir, 'levels-manifest.json');
   levelPackStats = splitLevelBundles(levelPrefabsSrc, webglDir, manifestPath, tmp);
+  const brStats = brotliCompressWebglBundles(webglDir);
+  console.log(`>>> bundle Brotli: ${brStats.count} 个, 节省 ${formatBytes(brStats.saved)}`);
 }
 
 attachLevelsDatabase(outDir);
@@ -343,7 +406,14 @@ rmrf(standaloneDir);
 mkdirp(standaloneDir);
 copyFile(path.join(unityRef, 'index.html'), path.join(standaloneDir, 'index.html'));
 copyDir(path.join(unityRef, 'TemplateData'), path.join(standaloneDir, 'TemplateData'));
-for (const item of ['Build', 'StreamingAssets', ...['levels-database.json', 'levels-database.json.br']]) {
+for (const item of [
+  'Build',
+  'StreamingAssets',
+  'levels-database.json',
+  'levels-database.json.br',
+  'levels-db-index.json',
+  'levels-db-index.json.br',
+]) {
   const src = path.join(outDir, item);
   const dst = path.join(standaloneDir, item);
   if (!fs.existsSync(src)) continue;
@@ -372,6 +442,6 @@ for (const p of requiredBundles) {
 
 const preloadNote = MERGE_LEVELS
   ? 'scenes ∥ assets_all 合并包 (MERGE_LEVELS=1)'
-  : `scenes ∥ assets_core 首屏；关卡包进关按需 (${levelPackStats ? levelPackStats.packed : '?'} 关)`;
+  : `scenes ∥ assets_core 首屏（引擎启动必需）；关卡库分片 + 关卡 bundle 进关按需 (${levelPackStats ? levelPackStats.packed : '?'} 关)`;
 console.log('\n完成。运行时包 → 本地 import-to-unity.sh / OSS unitycdndir（同一目录）');
 printPackageReport(outDir, { preloadNote });
diff --git a/tools/package-for-project.js b/tools/package-for-project.js
index 1c66d14..e9e2174 100644
--- a/tools/package-for-project.js
+++ b/tools/package-for-project.js
@@ -25,6 +25,7 @@ const {
   minifyLevelsDatabase,
   brotliCompressFile,
   patchPreloadSettings,
+  patchSplashSettings,
   printPackageReport,
   formatBytes,
 } = require('./package-optimize');
@@ -201,6 +202,7 @@ function patchSettingsForFrontend(settingsFile) {
       preloadResources: opts.preloadResources,
       preloadLevelPrefabs: opts.preloadLevelPrefabs,
     });
+    patchSplashSettings(j, { stripSplashAssets: true });
     if (j.rendering) {
       j.rendering.effectSettingsPath = `${UNITY_BASE}src/effect.bin`;
     }
diff --git a/tools/package-for-project.sh b/tools/package-for-project.sh
index 737c9ad..a74d1e0 100755
--- a/tools/package-for-project.sh
+++ b/tools/package-for-project.sh
@@ -32,10 +32,11 @@ usage() {
   echo "  --skip-manifest     不生成 deploy/ 清单" >&2
   echo "  --zip               额外生成 build/mstest5-runtime.zip" >&2
   echo "" >&2
-  echo "默认分包: assets_all 首屏含 level-prefabs 壳；每关独立 bundle 进关按需" >&2
+  echo "默认分包: scenes 首屏；assets_all / 关卡库分片 / 每关 bundle 进关按需" >&2
   echo "  MERGE_LEVELS=1  合并 level-prefabs 进 assets_all（不推荐）" >&2
   echo "运行时包结构（本地 static/unity = OSS unitycdndir）:" >&2
-  echo "  Build/ StreamingAssets/ levels-database.json(.br)" >&2
+  echo "  Build/ StreamingAssets/ levels-db-index.json(.br) levels-database.json(.br)" >&2
+  echo "  首屏: scenes_all + assets_all；进关: 关卡库分片 + 关卡 bundle" >&2
   echo "" >&2
   echo "步骤 2: scratch-gui/static/unity/import-to-unity.sh" >&2
 }
diff --git a/tools/package-optimize.js b/tools/package-optimize.js
index 5a52f21..f9e56b6 100644
--- a/tools/package-optimize.js
+++ b/tools/package-optimize.js
@@ -3,8 +3,10 @@
  * 供 package-for-project.js / package-for-cdn.js 共用。
  */
 const fs = require('fs');
+const os = require('os');
 const path = require('path');
 const zlib = require('zlib');
+const { execSync } = require('child_process');
 
 function formatBytes(n) {
   if (n >= 1024 * 1024) return `${(n / 1024 / 1024).toFixed(1)} MB`;
@@ -46,6 +48,23 @@ function brotliCompressFile(srcPath, dstPath, quality = 9) {
   return { raw: input.length, br: out.length };
 }
 
+/** 为 WebGL 目录下所有 .bundle 生成 .bundle.br */
+function brotliCompressWebglBundles(webglDir, opts = {}) {
+  if (!fs.existsSync(webglDir)) return { count: 0, saved: 0 };
+  let count = 0;
+  let saved = 0;
+  for (const name of fs.readdirSync(webglDir)) {
+    if (!name.endsWith('.bundle') || name.endsWith('.bundle.br')) continue;
+    const src = path.join(webglDir, name);
+    if (!fs.statSync(src).isFile()) continue;
+    const { raw, br } = brotliCompressFile(src, src + '.br', opts.quality);
+    count += 1;
+    saved += raw - br;
+    console.log(`>>> ${name}.br: ${formatBytes(raw)} → ${formatBytes(br)}`);
+  }
+  return { count, saved };
+}
+
 /**
  * 调整预加载 bundle：默认只预加载 main，resources / level-prefabs 按需加载。
  * @param {object} opts
@@ -68,6 +87,50 @@ function patchPreloadSettings(settingsObj, opts = {}) {
   return settingsObj;
 }
 
+/**
+ * 关闭 Cocos 启动闪屏（"Created with Cocos"）。
+ * totalTime <= 0 时引擎跳过闪屏等待，首屏可快约 2s；不影响关卡切换与网络下载。
+ * @param {object} opts
+ * @param {boolean} [opts.disableSplash=true]
+ * @param {boolean} [opts.stripSplashAssets=false] 去掉内嵌 logo/background，略减 scenes 包体积
+ */
+function patchSplashSettings(settingsObj, opts = {}) {
+  const disableSplash = opts.disableSplash !== false;
+  if (!disableSplash) return settingsObj;
+
+  settingsObj.splashScreen = settingsObj.splashScreen || {};
+  settingsObj.splashScreen.totalTime = 0;
+
+  if (opts.stripSplashAssets) {
+    delete settingsObj.splashScreen.logo;
+    delete settingsObj.splashScreen.background;
+  }
+  return settingsObj;
+}
+
+/**
+ * 就地修改 zip bundle 内的 settings.json（必须用 zip -0 store，loader 不支持 deflate）。
+ */
+function patchSplashInZipBundle(zipPath, opts = {}) {
+  const absZip = path.resolve(zipPath);
+  const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'cocos-splash-'));
+  try {
+    execSync(`unzip -q -o "${absZip}" -d "${tmp}"`, { stdio: 'pipe' });
+    const settingsPath = path.join(tmp, 'src', 'settings.json');
+    if (!fs.existsSync(settingsPath)) return false;
+    const j = JSON.parse(fs.readFileSync(settingsPath, 'utf8'));
+    patchSplashSettings(j, opts);
+    fs.writeFileSync(settingsPath, JSON.stringify(j));
+    const newZip = absZip + '.new';
+    if (fs.existsSync(newZip)) fs.unlinkSync(newZip);
+    execSync(`cd "${tmp}" && zip -0 -q -r "${newZip}" .`, { stdio: 'pipe' });
+    fs.renameSync(newZip, absZip);
+    return true;
+  } finally {
+    fs.rmSync(tmp, { recursive: true, force: true });
+  }
+}
+
 function printPackageReport(outDir, opts = {}) {
   const lines = ['\n>>> 包体积报告:'];
   const entries = [
@@ -101,6 +164,9 @@ module.exports = {
   fileSize,
   minifyLevelsDatabase,
   brotliCompressFile,
+  brotliCompressWebglBundles,
   patchPreloadSettings,
+  patchSplashSettings,
+  patchSplashInZipBundle,
   printPackageReport,
 };
diff --git a/tools/runtime-pack.js b/tools/runtime-pack.js
index 238847b..bc6dee3 100644
--- a/tools/runtime-pack.js
+++ b/tools/runtime-pack.js
@@ -6,13 +6,21 @@
  *   StreamingAssets/
  *   levels-database.json
  *   levels-database.json.br
+ *   levels-db-index.json
+ *   levels-db-index.json.br
+ *   StreamingAssets/aa/levels-db/
  *
  * 不含 index.html / TemplateData（仅 standalone-player 独立调试页使用）
  */
 const fs = require('fs');
 const path = require('path');
 
-const RUNTIME_ROOT_FILES = ['levels-database.json', 'levels-database.json.br'];
+const RUNTIME_ROOT_FILES = [
+  'levels-database.json',
+  'levels-database.json.br',
+  'levels-db-index.json',
+  'levels-db-index.json.br',
+];
 const RUNTIME_DIRS = ['Build', 'StreamingAssets'];
 
 function walkFiles(root, bucket, prefix = '') {
@@ -62,6 +70,9 @@ function assertRuntimePack(packDir, opts) {
   if (!fs.existsSync(catalog)) {
     throw new Error(`缺少运行时包: ${catalog}`);
   }
+  if (!fs.existsSync(path.join(packDir, 'levels-db-index.json'))) {
+    throw new Error(`缺少运行时包: ${path.join(packDir, 'levels-db-index.json')}`);
+  }
   if (!fs.existsSync(path.join(packDir, 'levels-database.json'))) {
     throw new Error(`缺少运行时包: ${path.join(packDir, 'levels-database.json')}`);
   }
diff --git a/tools/split-levels-database.js b/tools/split-levels-database.js
new file mode 100644
index 0000000..a23c64f
--- /dev/null
+++ b/tools/split-levels-database.js
@@ -0,0 +1,94 @@
+#!/usr/bin/env node
+/**
+ * 将 levels-database.json 拆为 index + 分片，首屏只下 index（~几 KB）。
+ *
+ * 输出:
+ *   <outDir>/levels-db-index.json (+ .br)
+ *   <outDir>/StreamingAssets/aa/levels-db/<min>-<max>.json (+ .br)
+ */
+const fs = require('fs');
+const path = require('path');
+const { brotliCompressFile, formatBytes } = require('./package-optimize');
+
+const DEFAULT_SHARD_SIZE = 100;
+
+function mkdirp(p) { fs.mkdirSync(p, { recursive: true }); }
+
+/**
+ * @param {string} srcPath  assets/level-data/levels-database.json
+ * @param {string} outDir   运行时包根目录
+ * @param {{ shardSize?: number }} opts
+ */
+function splitLevelsDatabase(srcPath, outDir, opts = {}) {
+  const shardSize = opts.shardSize || DEFAULT_SHARD_SIZE;
+  const raw = JSON.parse(fs.readFileSync(srcPath, 'utf8'));
+  const levels = raw.levels || {};
+  const ids = Object.keys(levels)
+    .map((k) => parseInt(k, 10))
+    .filter((n) => !Number.isNaN(n))
+    .sort((a, b) => a - b);
+
+  if (ids.length < 1) {
+    throw new Error(`关卡库为空: ${srcPath}`);
+  }
+
+  const min = ids[0];
+  const max = ids[ids.length - 1];
+  const shardDir = path.join(outDir, 'StreamingAssets', 'aa', 'levels-db');
+  mkdirp(shardDir);
+
+  const shards = [];
+  for (let start = min; start <= max; start += shardSize) {
+    const end = Math.min(start + shardSize - 1, max);
+    const slice = {};
+    for (const id of ids) {
+      if (id >= start && id <= end) {
+        slice[String(id)] = levels[String(id)];
+      }
+    }
+    if (!Object.keys(slice).length) continue;
+
+    const fileName = `${start}-${end}.json`;
+    const relFile = `levels-db/${fileName}`;
+    const absPath = path.join(shardDir, fileName);
+    fs.writeFileSync(absPath, JSON.stringify({ levels: slice }), 'utf8');
+    const br = brotliCompressFile(absPath, absPath + '.br');
+    console.log(`>>> levels-db/${fileName}: ${formatBytes(br.raw)} → .br ${formatBytes(br.br)}`);
+
+    shards.push({ min: start, max: end, file: relFile, count: Object.keys(slice).length });
+  }
+
+  const index = {
+    version: 2,
+    mode: 'sharded',
+    shardSize,
+    levelIdBase: raw.levelIdBase,
+    generatedAt: raw.generatedAt || new Date().toISOString(),
+    source: raw.source || 'split-levels-database',
+    total: ids.length,
+    min,
+    max,
+    stats: raw.stats,
+    shards,
+  };
+
+  const indexPath = path.join(outDir, 'levels-db-index.json');
+  fs.writeFileSync(indexPath, JSON.stringify(index), 'utf8');
+  const indexBr = brotliCompressFile(indexPath, indexPath + '.br');
+  console.log(`>>> levels-db-index.json: ${formatBytes(indexBr.raw)} → .br ${formatBytes(indexBr.br)}`);
+  console.log(`>>> 关卡库分片: ${shards.length} 片, ${ids.length} 关 (${min}–${max})`);
+
+  return { index, shards, total: ids.length };
+}
+
+module.exports = { splitLevelsDatabase, DEFAULT_SHARD_SIZE };
+
+if (require.main === module) {
+  const src = path.resolve(process.argv[2]);
+  const out = path.resolve(process.argv[3]);
+  if (!src || !out) {
+    console.error('Usage: split-levels-database.js <levels-database.json> <outDir>');
+    process.exit(1);
+  }
+  splitLevelsDatabase(src, out);
+}
diff --git a/web-template/mstest5-cocos-loader.js b/web-template/mstest5-cocos-loader.js
index 11b6648..3c403f8 100644
--- a/web-template/mstest5-cocos-loader.js
+++ b/web-template/mstest5-cocos-loader.js
@@ -10,6 +10,11 @@
   var streamingBase = '';
   var bundleManifest = null;
   var levelsManifest = null;
+  var levelsManifestPromise = null;
+  var assetsCoreLoaded = false;
+  var assetsCorePromise = null;
+  var loadedLevelDbShards = new Set();
+  var levelDbShardPromises = new Map();
   var levelPackPromises = new Map();
   var loadedLevelIds = new Set();
   var levelPrefabsBundlePromise = null;
@@ -54,9 +59,8 @@
       return;
     }
     var existing = am.getBundle('level-prefabs');
-    if (existing) {
-      if (onComplete) onComplete(null, existing);
-      return existing;
+    if (existing && typeof am.removeBundle === 'function') {
+      try { am.removeBundle(existing); } catch (e) { /* ignore */ }
     }
     if (levelPrefabsBundlePromise) {
       levelPrefabsBundlePromise.then(function (bundle) {
@@ -131,6 +135,40 @@
     }
   }
 
+  /** Cocos bundle 常请求 import/NN/uuid.json，zip 内路径带 assets/.../import/ 前缀（NN 为 uuid 前 2 位 hex） */
+  var IMPORT_SHARD = '[0-9a-fA-F]{2}';
+  function resolveImportFileKey(pathname) {
+    if (!pathname) return null;
+    var p = String(pathname).replace(/\\/g, '/').replace(/^\/+/, '');
+    var shardRe = new RegExp('^unity/assets/(level-prefabs|resources|main|internal)/(' + IMPORT_SHARD + ')/(.+)$', 'i');
+    p = p.replace(shardRe, function (_, bundle, dir, file) {
+      return 'assets/' + bundle + '/import/' + dir + '/' + file;
+    });
+    if (files.has(p)) return p;
+    var bundleImport = new RegExp('^assets/(level-prefabs|resources|main|internal)/(' + IMPORT_SHARD + ')/([^/]+)$', 'i').exec(p);
+    if (bundleImport) {
+      var withImport = 'assets/' + bundleImport[1] + '/import/' + bundleImport[2] + '/' + bundleImport[3];
+      if (files.has(withImport)) return withImport;
+    }
+    var short = new RegExp('^(' + IMPORT_SHARD + ')/(.+)$', 'i').exec(p);
+    if (short) {
+      var bases = [
+        'assets/level-prefabs/import/',
+        'assets/resources/import/',
+        'assets/main/import/',
+        'assets/internal/import/',
+        'assets/resources/native/',
+        'assets/main/native/',
+        'assets/internal/native/',
+      ];
+      for (var i = 0; i < bases.length; i++) {
+        var key = bases[i] + short[1] + '/' + short[2];
+        if (files.has(key)) return key;
+      }
+    }
+    return null;
+  }
+
   function lookupFile(pathname) {
     var keys = [pathname, pathname.replace(/^\.?\//, '')];
     var parts = pathname.split('/');
@@ -141,6 +179,8 @@
     for (var i = 0; i < keys.length; i++) {
       var k = keys[i];
       if (files.has(k)) return files.get(k);
+      var importKey = resolveImportFileKey(k);
+      if (importKey && files.has(importKey)) return files.get(importKey);
       var idx = k.indexOf('StreamingAssets/aa/WebGL/');
       if (idx >= 0 && files.has(k.slice(idx + 'StreamingAssets/aa/WebGL/'.length))) {
         return files.get(k.slice(idx + 'StreamingAssets/aa/WebGL/'.length));
@@ -151,6 +191,8 @@
       }
       if (k.indexOf('assets/') === 0 && files.has(k)) return files.get(k);
     }
+    var fallbackKey = resolveImportFileKey(pathname);
+    if (fallbackKey && files.has(fallbackKey)) return files.get(fallbackKey);
     return null;
   }
 
@@ -221,10 +263,20 @@
       var u = new URL(String(raw), global.location.href);
       var p = u.pathname;
       if (files.size > 0) {
+        var importKey = resolveImportFileKey(p) || resolveImportFileKey(p.replace(/^\/+/, ''));
+        if (importKey) {
+          var importVirt = virtualUrlForBundleFile(importKey);
+          if (importVirt) return importVirt;
+        }
         var rel = relPathFromUrlPath(p);
         if (rel) {
           var virt = virtualUrlForBundleFile(rel);
           if (virt) return virt;
+          importKey = resolveImportFileKey(rel);
+          if (importKey) {
+            importVirt = virtualUrlForBundleFile(importKey);
+            if (importVirt) return importVirt;
+          }
         }
       }
       if (p.indexOf(getRootPathname()) === 0) return u.href;
@@ -366,6 +418,12 @@
     proto.__tfrhLevelPrefabScript = true;
   }
 
+  function needsAssetsCore(pathname) {
+    var p = String(pathname || '');
+    if (needsLevelPrefabs(p)) return false;
+    return p.indexOf('assets/') >= 0 || p.indexOf('/assets/') >= 0;
+  }
+
   function installFetchShim() {
     global.fetch = function (input, init) {
       input = rewriteEmbeddedUrl(input);
@@ -378,6 +436,19 @@
           headers: { 'Content-Type': mimeForPath(p) },
         }));
       }
+      if (needsAssetsCore(p)) {
+        return ensureAssetsCoreLoaded().then(function () {
+          var hit2 = lookupFile(p);
+          if (hit2) {
+            var body2 = /\.(m?js|json)$/i.test(p) ? bytesToText(hit2) : hit2;
+            return new Response(body2, {
+              status: 200,
+              headers: { 'Content-Type': mimeForPath(p) },
+            });
+          }
+          return origFetch(input, init);
+        });
+      }
       if (needsLevelPrefabs(p)) {
         return ensureLevelPackForPath(p).then(function () {
           var hit2 = lookupFile(p);
@@ -407,6 +478,18 @@
         var origSend = xhr.send;
         xhr.send = function () {
           var hit = lookupFile(toPath(reqUrl));
+          if (!hit && needsAssetsCore(reqUrl)) {
+            ensureAssetsCoreLoaded().then(function () {
+              hit = lookupFile(toPath(reqUrl));
+              if (!hit) return origSend.apply(xhr, arguments);
+              var isText = /\.(m?js|json|txt|xml|atlas|tmx|tsx|vsh|fsh|fnt|plist)$/i.test(toPath(reqUrl))
+                || xhr.responseType === 'json'
+                || xhr.responseType === 'text'
+                || !xhr.responseType;
+              deliverXhrHit(xhr, isText ? bytesToText(hit) : null, isText ? null : hit);
+            }).catch(function () { origSend.apply(xhr, arguments); });
+            return;
+          }
           if (!hit && needsLevelPrefabs(reqUrl)) {
             ensureLevelPackForPath(reqUrl).then(function () {
               hit = lookupFile(toPath(reqUrl));
@@ -510,32 +593,36 @@
       if (onProgress) pending.then(function () { onProgress(1); }).catch(function () {});
       return pending;
     }
-    if (!levelsManifest || !levelsManifest.levels || !levelsManifest.levels[levelId]) {
-      return Promise.reject(new Error('关卡包未在 manifest 中: Level' + levelId));
-    }
-    if (!streamingBase) return Promise.reject(new Error('streamingBase 未初始化'));
-    var entry = levelsManifest.levels[levelId];
-    var url = joinUrl(streamingBase, 'aa/WebGL/' + entry.bundle);
-    dispatchLevelsBundleProgress(0);
-    var promise = fetchBinaryWithProgress(
-      url,
-      function (frac) {
-        dispatchLevelsBundleProgress(frac);
-        if (onProgress) onProgress(frac);
-      },
-      0,
-      1,
-    ).then(function (buf) {
-      mergeZipIntoFiles(unzip(buf));
-      var ok = (entry.files || []).every(function (rel) { return files.has(rel); });
-      if (!ok) {
-        throw new Error('关卡包解压不完整: Level' + levelId);
-      }
-      loadedLevelIds.add(levelId);
-      return invalidateLevelPrefabsBundle();
+    var promise = ensureAssetsCoreLoaded().then(function () {
+      return ensureLevelsManifestLoaded();
     }).then(function () {
-      dispatchLevelsBundleProgress(1);
-      if (onProgress) onProgress(1);
+      if (!levelsManifest || !levelsManifest.levels || !levelsManifest.levels[levelId]) {
+        return Promise.reject(new Error('关卡包未在 manifest 中: Level' + levelId));
+      }
+      if (!streamingBase) return Promise.reject(new Error('streamingBase 未初始化'));
+      var entry = levelsManifest.levels[levelId];
+      var url = joinUrl(streamingBase, 'aa/WebGL/' + entry.bundle);
+      dispatchLevelsBundleProgress(0);
+      return fetchBinaryWithProgress(
+        url,
+        function (frac) {
+          dispatchLevelsBundleProgress(frac);
+          if (onProgress) onProgress(frac);
+        },
+        0,
+        1,
+      ).then(function (buf) {
+        mergeZipIntoFiles(unzip(buf));
+        var ok = (entry.files || []).every(function (rel) { return files.has(rel); });
+        if (!ok) {
+          throw new Error('关卡包解压不完整: Level' + levelId);
+        }
+        loadedLevelIds.add(levelId);
+        return invalidateLevelPrefabsBundle();
+      }).then(function () {
+        dispatchLevelsBundleProgress(1);
+        if (onProgress) onProgress(1);
+      });
     }).catch(function (e) {
       levelPackPromises.delete(levelId);
       throw e;
@@ -721,6 +808,7 @@
     var raw = String(path || '').trim();
     var m = /Level(\d+)/.exec(raw);
     var lid = m ? parseInt(m[1], 10) : NaN;
+    var loadPath = raw.indexOf('level-prefabs/') === 0 ? raw : ('level-prefabs/' + raw.replace(/^level-prefabs\//, ''));
     var prep = (typeof global.__tfrhEnsureLevelPack === 'function' && !Number.isNaN(lid))
       ? global.__tfrhEnsureLevelPack(lid)
       : Promise.resolve();
@@ -728,17 +816,35 @@
     return prep.then(function () {
       return invalidateLevelPrefabsBundle();
     }).then(function () {
+      return ensureLevelsManifestLoaded();
+    }).then(function (manifest) {
+      var entry = manifest && manifest.levels && manifest.levels[String(lid)];
+      var uuid = entry && entry.uuid;
       return new Promise(function (resolve, reject) {
-        cc.assetManager.loadBundle('level-prefabs', function (err, bundle) {
-          if (err || !bundle) {
-            reject(err || new Error('level-prefabs bundle unavailable'));
-            return;
-          }
-          bundle.load(raw, Prefab, function (e, asset) {
-            if (e || !asset) reject(e || new Error('missing prefab: ' + raw));
-            else resolve(asset);
+        function finish(err, asset) {
+          if (!err && asset) resolve(asset);
+          else reject(err || new Error('missing prefab: ' + loadPath));
+        }
+        function tryBundleLoad() {
+          cc.assetManager.loadBundle('level-prefabs', function (err, bundle) {
+            if (err || !bundle) {
+              reject(err || new Error('level-prefabs bundle unavailable'));
+              return;
+            }
+            bundle.load(loadPath, Prefab, finish);
           });
-        });
+        }
+        if (uuid) {
+          cc.assetManager.loadAny({ uuid: uuid, type: Prefab }, function (err, asset) {
+            if (!err && asset) {
+              resolve(asset);
+              return;
+            }
+            tryBundleLoad();
+          });
+          return;
+        }
+        tryBundleLoad();
       });
     });
   }
@@ -1060,26 +1166,83 @@
     return out;
   }
 
+  function isZipBytes(bytes) {
+    return bytes && bytes.length >= 2 && bytes[0] === 0x50 && bytes[1] === 0x4b;
+  }
+
+  function isJsonText(text) {
+    if (!text) return false;
+    var c = text.charCodeAt(0);
+    return c === 0x7b || c === 0x5b;
+  }
+
+  function decodeBrotliToBytes(ab) {
+    if (typeof DecompressionStream !== 'undefined') {
+      return new Response(ab).pipeThrough(new DecompressionStream('brotli'))
+        .arrayBuffer()
+        .then(function (buf) { return new Uint8Array(buf); });
+    }
+    return Promise.reject(new Error('浏览器不支持 Brotli 解压'));
+  }
+
+  /** OSS 若对 .br 文件再设 Content-Encoding:br，fetch 已解压成 zip/json，勿二次 Brotli */
+  function normalizeBinaryPayload(bytes, expectBrotli) {
+    if (!expectBrotli || isZipBytes(bytes)) {
+      return Promise.resolve(bytes);
+    }
+    var slice = bytes.buffer.slice(bytes.byteOffset, bytes.byteOffset + bytes.byteLength);
+    return decodeBrotliToBytes(slice).catch(function () {
+      if (isZipBytes(bytes)) return bytes;
+      return Promise.reject(new Error('Brotli 解压失败'));
+    });
+  }
+
   function fetchBinary(url, onProgress) {
-    return origFetch(url).then(function (res) {
-      if (!res.ok) throw new Error('HTTP ' + res.status + ' for ' + url);
-      if (onProgress) onProgress(0.3);
-      return res.arrayBuffer();
-    }).then(function (ab) {
-      if (onProgress) onProgress(0.6);
-      return new Uint8Array(ab);
+    return fetchBinaryWithProgress(url, onProgress, 0, 1);
+  }
+
+  function decodeBrotliToText(ab) {
+    if (typeof DecompressionStream !== 'undefined') {
+      return new Response(ab).pipeThrough(new DecompressionStream('brotli'))
+        .arrayBuffer()
+        .then(function (buf) { return new TextDecoder().decode(buf); });
+    }
+    return Promise.reject(new Error('浏览器不支持 Brotli 解压'));
+  }
+
+  function normalizeJsonPayload(ab, expectBrotli) {
+    var text = new TextDecoder().decode(ab);
+    if (!expectBrotli || isJsonText(text)) return Promise.resolve(text);
+    return decodeBrotliToText(ab).catch(function () {
+      text = new TextDecoder().decode(ab);
+      if (isJsonText(text)) return text;
+      return Promise.reject(new Error('Brotli JSON 解压失败'));
     });
   }
 
   function fetchBinaryWithProgress(url, onProgress, weightStart, weightEnd) {
     weightStart = weightStart == null ? 0 : weightStart;
     weightEnd = weightEnd == null ? 1 : weightEnd;
-    return origFetch(url).then(function (res) {
+    var brUrl = String(url).replace(/\.bundle(\?.*)?$/i, '.bundle.br$1');
+    if (!/\.br(\?|$)/i.test(brUrl) && brUrl.indexOf('.bundle') >= 0) {
+      /* brUrl already set */
+    } else if (/\.json(\?|$)/i.test(url)) {
+      brUrl = url.replace(/\.json(\?.*)?$/i, '.json.br$1');
+    } else if (!/\.br(\?|$)/i.test(url)) {
+      brUrl = url + '.br';
+    } else {
+      brUrl = url;
+    }
+
+    function readResponse(res, isBrotli) {
       if (!res.ok) throw new Error('HTTP ' + res.status + ' for ' + url);
       if (!res.body || !res.body.getReader) {
         return res.arrayBuffer().then(function (ab) {
-          if (onProgress) onProgress(weightEnd);
-          return new Uint8Array(ab);
+          var bytes = new Uint8Array(ab);
+          return normalizeBinaryPayload(bytes, isBrotli).then(function (out) {
+            if (onProgress) onProgress(weightEnd);
+            return out;
+          });
         });
       }
       var reader = res.body.getReader();
@@ -1089,13 +1252,19 @@
       function pump() {
         return reader.read().then(function (result) {
           if (result.done) {
-            if (onProgress) onProgress(weightEnd);
             var out = new Uint8Array(received);
             var off = 0;
             for (var i = 0; i < chunks.length; i++) {
               out.set(chunks[i], off);
               off += chunks[i].length;
             }
+            if (isBrotli) {
+              return normalizeBinaryPayload(out, true).then(function (decoded) {
+                if (onProgress) onProgress(weightEnd);
+                return decoded;
+              });
+            }
+            if (onProgress) onProgress(weightEnd);
             return out;
           }
           chunks.push(result.value);
@@ -1108,11 +1277,45 @@
         });
       }
       return pump();
+    }
+
+    return origFetch(brUrl).then(function (res) {
+      if (res.ok) return readResponse(res, true);
+      return origFetch(url).then(function (plain) { return readResponse(plain, false); });
+    }).catch(function () {
+      return origFetch(url).then(function (plain) { return readResponse(plain, false); });
     });
   }
 
+  function ensureAssetsCoreLoaded(onProgress) {
+    if (assetsCoreLoaded) return Promise.resolve();
+    if (assetsCorePromise) return assetsCorePromise;
+    if (!bundleManifest || !bundleManifest.assetsUrl) {
+      return Promise.reject(new Error('assets_all manifest 未就绪'));
+    }
+    assetsCorePromise = fetchBinaryWithProgress(
+      bundleManifest.assetsUrl,
+      onProgress || function () {},
+      0,
+      1,
+    ).then(function (buf) {
+      mergeZipIntoFiles(unzip(buf));
+      patchSettingsScriptPackages();
+      assetsCoreLoaded = true;
+    }).catch(function (e) {
+      assetsCorePromise = null;
+      throw e;
+    });
+    return assetsCorePromise;
+  }
+
+  global.__tfrhEnsureAssetsCore = function (onProgress) {
+    return ensureAssetsCoreLoaded(onProgress);
+  };
+
   function loadStartupBundles(manifest, onProgress) {
     onProgress(0.05);
+    /* internal/main 等引擎启动即需，assets_all 须与 scenes 并行首屏加载 */
     var scenesP = fetchBinaryWithProgress(manifest.scenesUrl, onProgress, 0.05, 0.42);
     var assetsP = fetchBinaryWithProgress(manifest.assetsUrl, onProgress, 0.42, 0.58);
     return Promise.all([scenesP, assetsP]).then(function (bufs) {
@@ -1120,6 +1323,7 @@
       assertCocosRuntimeLoaded();
       mergeZipIntoFiles(unzip(bufs[1]));
       patchSettingsScriptPackages();
+      assetsCoreLoaded = true;
       onProgress(0.6);
     });
   }
@@ -1190,6 +1394,58 @@
     });
   }
 
+  function ensureLevelsManifestLoaded() {
+    if (levelsManifest) return Promise.resolve(levelsManifest);
+    if (levelsManifestPromise) return levelsManifestPromise;
+    if (!streamingBase) return Promise.reject(new Error('streamingBase 未初始化'));
+    levelsManifestPromise = loadLevelsManifest(streamingBase).then(function (lm) {
+      levelsManifest = lm;
+      return lm;
+    });
+    return levelsManifestPromise;
+  }
+
+  function findLevelDbShard(index, levelId) {
+    if (!index || !index.shards) return null;
+    var id = Number(levelId);
+    for (var i = 0; i < index.shards.length; i++) {
+      var s = index.shards[i];
+      if (id >= s.min && id <= s.max) return s;
+    }
+    return null;
+  }
+
+  function ensureLevelDbShardLoaded(levelId) {
+    var index = global.__tfrhLevelsDbIndex;
+    if (!index || index.mode !== 'sharded') return Promise.resolve();
+    var shard = findLevelDbShard(index, levelId);
+    if (!shard) return Promise.resolve();
+    var key = shard.file;
+    if (loadedLevelDbShards.has(key)) return Promise.resolve();
+    if (levelDbShardPromises.has(key)) return levelDbShardPromises.get(key);
+    if (!streamingBase) return Promise.reject(new Error('streamingBase 未初始化'));
+    var url = joinUrl(streamingBase, 'aa/' + key.replace(/^\/+/, ''));
+    var promise = fetchLevelsDatabaseJson(url).then(function (json) {
+      loadedLevelDbShards.add(key);
+      if (!global.__tfrhLevelsDatabaseJson) {
+        global.__tfrhLevelsDatabaseJson = { version: index.version || 2, levels: {} };
+      }
+      var merged = global.__tfrhLevelsDatabaseJson.levels || {};
+      var incoming = (json && json.levels) || {};
+      Object.keys(incoming).forEach(function (k) { merged[k] = incoming[k]; });
+      global.__tfrhLevelsDatabaseJson.levels = merged;
+    }).catch(function (e) {
+      levelDbShardPromises.delete(key);
+      throw e;
+    });
+    levelDbShardPromises.set(key, promise);
+    return promise;
+  }
+
+  global.__tfrhEnsureLevelDbShard = function (levelId) {
+    return ensureLevelDbShardLoaded(levelId);
+  };
+
   function loadBundleManifest(config) {
     var base = resolveStreamingBase(config);
     var catalogUrl = joinUrl(base, 'aa/catalog.json');
@@ -1198,16 +1454,13 @@
       return res.json();
     }).then(function (catalog) {
       var bundles = parseCatalogBundles(catalog);
-      return loadLevelsManifest(base).then(function (lm) {
-        levelsManifest = lm;
-        var manifest = {
-          scenesUrl: joinUrl(base, 'aa/WebGL/' + bundles.scenes),
-          assetsUrl: joinUrl(base, 'aa/WebGL/' + bundles.assets),
-          bundleNames: bundles,
-        };
-        bundleManifest = manifest;
-        return manifest;
-      });
+      var manifest = {
+        scenesUrl: joinUrl(base, 'aa/WebGL/' + bundles.scenes),
+        assetsUrl: joinUrl(base, 'aa/WebGL/' + bundles.assets),
+        bundleNames: bundles,
+      };
+      bundleManifest = manifest;
+      return manifest;
     });
   }
 
@@ -1268,36 +1521,33 @@
   packageRoot = getPackageRoot();
   installEmbeddedPathFix();
 
-  function resolveLevelsDatabaseUrl(config) {
-    if (global.__tfrhLevelsDatabaseUrl) return global.__tfrhLevelsDatabaseUrl;
+  function resolveLevelsDbBase(config) {
     var sa = config && config.streamingAssetsUrl;
     if (sa && /^https?:\/\//i.test(sa)) {
-      var cdnRoot = String(sa).replace(/\/StreamingAssets\/?$/i, '');
-      return joinUrl(cdnRoot, 'levels-database.json');
+      return String(sa).replace(/\/StreamingAssets\/?$/i, '');
     }
-    return joinUrl(packageRoot || getPackageRoot(), 'levels-database.json');
+    return packageRoot || getPackageRoot();
   }
 
-  function decodeBrotliToText(ab) {
-    if (typeof DecompressionStream !== 'undefined') {
-      return new Response(ab).pipeThrough(new DecompressionStream('brotli'))
-        .arrayBuffer()
-        .then(function (buf) { return new TextDecoder().decode(buf); });
-    }
-    return Promise.reject(new Error('浏览器不支持 Brotli 解压'));
+  function resolveLevelsDatabaseUrl(config) {
+    if (global.__tfrhLevelsDatabaseUrl) return global.__tfrhLevelsDatabaseUrl;
+    return joinUrl(resolveLevelsDbBase(config), 'levels-database.json');
+  }
+
+  function resolveLevelsDbIndexUrl(config) {
+    if (global.__tfrhLevelsDbIndexUrl) return global.__tfrhLevelsDbIndexUrl;
+    return joinUrl(resolveLevelsDbBase(config), 'levels-db-index.json');
   }
 
   function fetchLevelsDatabaseJson(url) {
     var brUrl = url.replace(/\.json(\?.*)?$/i, '.json.br$1');
     return origFetch(brUrl).then(function (res) {
       if (!res.ok) throw new Error('HTTP ' + res.status);
-      var enc = (res.headers.get('content-encoding') || '').toLowerCase();
-      if (enc === 'br' || /\.br(\?|$)/i.test(brUrl)) {
-        return res.arrayBuffer().then(decodeBrotliToText).then(function (text) {
+      return res.arrayBuffer().then(function (ab) {
+        return normalizeJsonPayload(ab, true).then(function (text) {
           return JSON.parse(text);
         });
-      }
-      return res.json();
+      });
     }).catch(function () {
       return origFetch(url).then(function (res) {
         if (!res.ok) throw new Error('HTTP ' + res.status);
@@ -1306,14 +1556,20 @@
     });
   }
 
-  function prefetchMainSiteLevelDb(config) {
-    var url = resolveLevelsDatabaseUrl(config);
-    global.__tfrhLevelsDatabaseUrl = url;
-    if (!url || global.__tfrhLevelsDatabaseJson) return Promise.resolve();
-    return fetchLevelsDatabaseJson(url).then(function (json) {
-      global.__tfrhLevelsDatabaseJson = json;
+  function prefetchLevelDbIndex(config) {
+    var indexUrl = resolveLevelsDbIndexUrl(config);
+    var legacyUrl = resolveLevelsDatabaseUrl(config);
+    global.__tfrhLevelsDbIndexUrl = indexUrl;
+    global.__tfrhLevelsDatabaseUrl = legacyUrl;
+    if (global.__tfrhLevelsDbIndex) return Promise.resolve();
+    return fetchLevelsDatabaseJson(indexUrl).then(function (json) {
+      if (json && json.mode === 'sharded') {
+        global.__tfrhLevelsDbIndex = json;
+        return;
+      }
+      throw new Error('非分片索引');
     }).catch(function (e) {
-      console.warn('[mstest5] 关卡库预取失败', url, e);
+      console.warn('[mstest5] 关卡库索引预取失败，启动时将由 LevelDatabase 回退', indexUrl, e);
     });
   }
 
@@ -1339,7 +1595,7 @@
     onProgress = onProgress || function () {};
     onProgress(0.02);
     resolveStreamingBase(config);
-    return prefetchMainSiteLevelDb(config).then(function () {
+    return prefetchLevelDbIndex(config).then(function () {
       return shouldUseBundlePackFlow(config);
     }).then(function (useBundles) {
       if (!useBundles) {