diff --git a/src/main.ts b/src/main.ts
index 3900dc1..d03e2af 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -5,6 +5,7 @@ import { spawn, ChildProcess, execSync, exec, spawnSync } from 'child_process';
 import axios from 'axios';
 import { autoUpdater } from 'electron-updater';
 import { compareUpdateVersions, isNewerUpdateVersion, normalizeUpdateVersion } from './update-version-utils';
+import { CustomClip, MergeGroupItem, MergeGroup, QueueItem, DownloadProgress, DownloadResult } from './types';
 
 // ==========================================
 // CONFIG & CONSTANTS
@@ -156,57 +157,6 @@ interface VOD {
     stream_id: string;
 }
 
-interface CustomClip {
-    startSec: number;
-    durationSec: number;
-    startPart: number;
-    filenameFormat: 'simple' | 'timestamp' | 'template';
-    filenameTemplate?: string;
-}
-
-interface MergeGroupItem {
-    url: string;
-    title: string;
-    date: string;
-    streamer: string;
-    duration_str: string;
-}
-
-interface MergeGroup {
-    items: MergeGroupItem[];
-    mergePhase: 'downloading' | 'merging' | 'splitting' | 'cleanup' | 'done';
-    currentItemIndex: number;
-    downloadedFiles: Record<number, string>;
-    mergedFile?: string;
-    splitFiles?: string[];
-    totalDurationSec?: number;
-}
-
-interface QueueItem {
-    id: string;
-    title: string;
-    url: string;
-    date: string;
-    streamer: string;
-    duration_str: string;
-    status: 'pending' | 'downloading' | 'paused' | 'completed' | 'error';
-    progress: number;
-    currentPart?: number;
-    totalParts?: number;
-    speed?: string;
-    eta?: string;
-    downloadedBytes?: number;
-    totalBytes?: number;
-    last_error?: string;
-    customClip?: CustomClip;
-    mergeGroup?: MergeGroup;
-}
-
-interface DownloadResult {
-    success: boolean;
-    error?: string;
-}
-
 interface PreflightChecks {
     internet: boolean;
     streamlink: boolean;
@@ -223,19 +173,6 @@ interface PreflightResult {
     timestamp: string;
 }
 
-interface DownloadProgress {
-    id: string;
-    progress: number;
-    speed: string;
-    speedBytesPerSec?: number;
-    eta: string;
-    status: string;
-    currentPart?: number;
-    totalParts?: number;
-    downloadedBytes?: number;
-    totalBytes?: number;
-}
-
 interface VideoInfo {
     duration: number;
     width: number;
diff --git a/src/preload.ts b/src/preload.ts
index a48b607..833c32c 100644
--- a/src/preload.ts
+++ b/src/preload.ts
@@ -1,62 +1,7 @@
 import { contextBridge, ipcRenderer } from 'electron';
+import { CustomClip, MergeGroupItem, MergeGroup, QueueItem, DownloadProgress } from './types';
 
 // Types
-interface CustomClip {
-    startSec: number;
-    durationSec: number;
-    startPart: number;
-    filenameFormat: 'simple' | 'timestamp' | 'template';
-    filenameTemplate?: string;
-}
-
-interface MergeGroupItem {
-    url: string;
-    title: string;
-    date: string;
-    streamer: string;
-    duration_str: string;
-}
-
-interface MergeGroup {
-    items: MergeGroupItem[];
-    mergePhase: 'downloading' | 'merging' | 'splitting' | 'cleanup' | 'done';
-    currentItemIndex: number;
-    downloadedFiles: Record<number, string>;
-    mergedFile?: string;
-    splitFiles?: string[];
-    totalDurationSec?: number;
-}
-
-interface QueueItem {
-    id: string;
-    title: string;
-    url: string;
-    date: string;
-    streamer: string;
-    duration_str: string;
-    status: 'pending' | 'downloading' | 'paused' | 'completed' | 'error';
-    progress: number;
-    currentPart?: number;
-    totalParts?: number;
-    speed?: string;
-    eta?: string;
-    customClip?: CustomClip;
-    mergeGroup?: MergeGroup;
-}
-
-interface DownloadProgress {
-    id: string;
-    progress: number;
-    speed: string;
-    speedBytesPerSec?: number;
-    eta: string;
-    status: string;
-    currentPart?: number;
-    totalParts?: number;
-    downloadedBytes?: number;
-    totalBytes?: number;
-}
-
 interface RuntimeMetricsSnapshot {
     cacheHits: number;
     cacheMisses: number;
diff --git a/src/types.ts b/src/types.ts
new file mode 100644
index 0000000..8e12d43
--- /dev/null
+++ b/src/types.ts
@@ -0,0 +1,63 @@
+export interface CustomClip {
+    startSec: number;
+    durationSec: number;
+    startPart: number;
+    filenameFormat: 'simple' | 'timestamp' | 'template';
+    filenameTemplate?: string;
+}
+
+export interface MergeGroupItem {
+    url: string;
+    title: string;
+    date: string;
+    streamer: string;
+    duration_str: string;
+}
+
+export interface MergeGroup {
+    items: MergeGroupItem[];
+    mergePhase: 'downloading' | 'merging' | 'splitting' | 'cleanup' | 'done';
+    currentItemIndex: number;
+    downloadedFiles: Record<number, string>;
+    mergedFile?: string;
+    splitFiles?: string[];
+    totalDurationSec?: number;
+}
+
+export interface QueueItem {
+    id: string;
+    title: string;
+    url: string;
+    date: string;
+    streamer: string;
+    duration_str: string;
+    status: 'pending' | 'downloading' | 'paused' | 'completed' | 'error';
+    progress: number;
+    currentPart?: number;
+    totalParts?: number;
+    speed?: string;
+    eta?: string;
+    downloadedBytes?: number;
+    totalBytes?: number;
+    last_error?: string;
+    customClip?: CustomClip;
+    mergeGroup?: MergeGroup;
+}
+
+export interface DownloadProgress {
+    id: string;
+    progress: number;
+    speed: string;
+    speedBytesPerSec?: number;
+    eta: string;
+    status: string;
+    currentPart?: number;
+    totalParts?: number;
+    downloadedBytes?: number;
+    totalBytes?: number;
+}
+
+export interface DownloadResult {
+    success: boolean;
+    error?: string;
+}