diff --git a/components/CreatePanel.tsx b/components/CreatePanel.tsx
index 6ecd102..b9a2a8f 100644
--- a/components/CreatePanel.tsx
+++ b/components/CreatePanel.tsx
@@ -1,5 +1,5 @@
 import React, { useState, useEffect, useRef, useCallback, useMemo } from 'react';
-import { Sparkles, ChevronDown, Settings2, Trash2, Music2, Sliders, Dices, Hash, RefreshCw, Plus, Upload, Play, Pause, Loader2 } from 'lucide-react';
+import { Sparkles, ChevronDown, Settings2, Trash2, Music2, Sliders, Dices, Hash, RefreshCw, Plus, Upload, Play, Pause, Loader2, AlertTriangle, CheckCircle2, ExternalLink } from 'lucide-react';
 import { GenerationParams, Song } from '../types';
 import { useAuth } from '../context/AuthContext';
 import { useI18n } from '../context/I18nContext';
@@ -237,6 +237,11 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
   // Available models fetched from backend
   const [fetchedModels, setFetchedModels] = useState<{ name: string; is_active: boolean; is_preloaded: boolean }[]>([]);
 
+  // The SFT DiT model name — required for repaint mode
+  const SFT_MODEL_NAME = 'acestep-v15-sft';
+  // The SFT model GGUF file to download when not present (Q8_0 is the default quality tier)
+  const SFT_MODEL_FILE = 'acestep-v15-sft-Q8_0.gguf';
+
   // Fallback model list when backend is unavailable
   const availableModels = useMemo(() => {
     if (fetchedModels.length > 0) {
@@ -244,7 +249,7 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
     }
     return [
       { id: 'acestep-v15-base', name: 'acestep-v15-base' },
-      { id: 'acestep-v15-sft', name: 'acestep-v15-sft' },
+      { id: SFT_MODEL_NAME, name: SFT_MODEL_NAME },
       { id: 'acestep-v15-turbo', name: 'acestep-v15-turbo' },
       { id: 'acestep-v15-turbo-shift1', name: 'acestep-v15-turbo-shift1' },
       { id: 'acestep-v15-turbo-shift3', name: 'acestep-v15-turbo-shift3' },
@@ -270,6 +275,16 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
     return modelId.includes('turbo');
   };
 
+  // Check if model is an SFT variant (required for repaint)
+  const isSftModel = (modelId: string): boolean => {
+    return modelId.includes('sft');
+  };
+
+  // SFT model download/availability state for repaint mode
+  type SftStatus = 'idle' | 'checking' | 'available' | 'downloading' | 'unavailable';
+  const [sftStatus, setSftStatus] = useState<SftStatus>('idle');
+  const sftSseRef = useRef<EventSource | null>(null);
+
   const [isUploadingReference, setIsUploadingReference] = useState(false);
   const [isUploadingSource, setIsUploadingSource] = useState(false);
   const [isTranscribingReference, setIsTranscribingReference] = useState(false);
@@ -575,6 +590,90 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
     }
   }, []);
 
+  // Check if the SFT model is on disk and download it if needed.
+  // Called automatically when repaint mode is selected.
+  const checkAndEnsureSftModel = useCallback(async () => {
+    setSftStatus('checking');
+    try {
+      const statusRes = await fetch('/api/models/status');
+      if (!statusRes.ok) { setSftStatus('unavailable'); return; }
+      const statusData = await statusRes.json();
+      const onDisk: string[] = statusData.onDisk || [];
+      const hasSft = onDisk.some((f: string) => f.startsWith(SFT_MODEL_NAME));
+
+      if (hasSft) {
+        setSftStatus('available');
+        return;
+      }
+
+      // SFT model not on disk — trigger download if authenticated
+      if (!token) { setSftStatus('unavailable'); return; }
+
+      setSftStatus('downloading');
+      // Enqueue download of the Q8_0 SFT DiT model
+      await fetch('/api/models/download', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json', Authorization: `Bearer ${token}` },
+        body: JSON.stringify({ files: [SFT_MODEL_FILE] }),
+      });
+
+      // Subscribe to SSE stream to detect when download completes
+      if (sftSseRef.current) sftSseRef.current.close();
+      const es = new EventSource('/api/models/download/stream');
+      sftSseRef.current = es;
+      const onDone = (e: MessageEvent) => {
+        try {
+          const data = JSON.parse(e.data);
+          if (data.filename?.startsWith(SFT_MODEL_NAME)) {
+            setSftStatus('available');
+            es.close();
+            sftSseRef.current = null;
+          }
+        } catch { /* ignore */ }
+      };
+      const onError = () => {
+        setSftStatus('unavailable');
+        es.close();
+        sftSseRef.current = null;
+      };
+      es.addEventListener('done', onDone);
+      es.addEventListener('error', onError);
+    } catch {
+      setSftStatus('unavailable');
+    }
+  }, [token]);
+
+  // Auto-switch to SFT model when repaint mode is selected and back to previous model otherwise
+  const prevTaskTypeRef = useRef(taskType);
+  const prevModelBeforeRepaintRef = useRef<string | null>(null);
+  useEffect(() => {
+    const prevTaskType = prevTaskTypeRef.current;
+    prevTaskTypeRef.current = taskType;
+
+    if (taskType === 'repaint') {
+      // Entering repaint mode: switch to SFT model if not already on one
+      if (!isSftModel(selectedModel)) {
+        prevModelBeforeRepaintRef.current = selectedModel;
+        setSelectedModel(SFT_MODEL_NAME);
+        localStorage.setItem('ace-model', SFT_MODEL_NAME);
+      }
+      // Check/download SFT model
+      void checkAndEnsureSftModel();
+    } else if (prevTaskType === 'repaint') {
+      // Leaving repaint mode: restore previous model if it was switched
+      if (sftSseRef.current) { sftSseRef.current.close(); sftSseRef.current = null; }
+      setSftStatus('idle');
+      if (prevModelBeforeRepaintRef.current && isSftModel(selectedModel)) {
+        setSelectedModel(prevModelBeforeRepaintRef.current);
+        localStorage.setItem('ace-model', prevModelBeforeRepaintRef.current);
+        prevModelBeforeRepaintRef.current = null;
+      }
+    }
+  }, [taskType, checkAndEnsureSftModel]);
+
+  // Clean up SSE on unmount
+  useEffect(() => () => { sftSseRef.current?.close(); }, []);
+
   useEffect(() => {
     const loadModelsAndLimits = async () => {
       await refreshModels();
@@ -919,6 +1018,35 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
     return `${minutes}:${String(seconds).padStart(2, '0')}`;
   };
 
+  /** Clear the source audio and reset task type if it was cover/repaint. */
+  const handleClearSourceAudio = () => {
+    setSourceAudioUrl('');
+    setSourceAudioTitle('');
+    setSourcePlaying(false);
+    setSourceTime(0);
+    setSourceDuration(0);
+    if (taskType === 'cover' || taskType === 'repaint') setTaskType('text2music');
+  };
+
+  /**
+   * Returns a green overlay element indicating the repaint region on the seekbar.
+   * Rendered only when taskType === 'repaint' and sourceDuration > 0.
+   */
+  const renderRepaintRegionOverlay = () => {
+    if (taskType !== 'repaint' || sourceDuration <= 0) return null;
+    const regionStart = Math.max(0, repaintingStart >= 0 ? repaintingStart : 0);
+    const regionEnd   = Math.min(sourceDuration, repaintingEnd >= 0 ? repaintingEnd : sourceDuration);
+    return (
+      <div
+        className="absolute inset-y-0 bg-emerald-400/40 dark:bg-emerald-400/30 rounded-full pointer-events-none"
+        style={{
+          left:  `${(regionStart / sourceDuration) * 100}%`,
+          width: `${Math.max(0, (regionEnd - regionStart) / sourceDuration) * 100}%`,
+        }}
+      />
+    );
+  };
+
   const toggleAudio = (target: 'reference' | 'source') => {
     const audio = target === 'reference' ? referenceAudioRef.current : sourceAudioRef.current;
     if (!audio) return;
@@ -1280,6 +1408,221 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
               </div>
             </div>
 
+            {/* Source Audio — Cover / Repaint (Simple Mode) */}
+            <div className="bg-white dark:bg-suno-card rounded-xl border border-zinc-200 dark:border-white/5 overflow-hidden">
+              <div className="px-3 py-2.5 border-b border-zinc-100 dark:border-white/5 bg-zinc-50 dark:bg-white/[0.02]">
+                <div className="flex items-center gap-2">
+                  <span className="text-xs font-bold text-zinc-500 dark:text-zinc-400 uppercase tracking-wide">
+                    {t('cover')} / {t('repaintMode')}
+                  </span>
+                  <span className="text-[9px] px-1.5 py-0.5 rounded bg-zinc-200 dark:bg-white/10 text-zinc-500 dark:text-zinc-400 font-medium uppercase">
+                    optional
+                  </span>
+                </div>
+              </div>
+              <div className="p-3 space-y-2">
+                {/* Source audio mini-player */}
+                {sourceAudioUrl && (
+                  <div className="flex items-center gap-3 p-2 rounded-lg bg-zinc-50 dark:bg-white/[0.03] border border-zinc-100 dark:border-white/5">
+                    <button
+                      type="button"
+                      onClick={() => toggleAudio('source')}
+                      className="relative flex-shrink-0 w-10 h-10 rounded-full bg-gradient-to-br from-emerald-500 to-teal-600 text-white flex items-center justify-center shadow-lg shadow-emerald-500/20 hover:scale-105 transition-transform"
+                    >
+                      {sourcePlaying ? (
+                        <svg className="w-4 h-4" fill="currentColor" viewBox="0 0 24 24"><path d="M6 4h4v16H6V4zm8 0h4v16h-4V4z"/></svg>
+                      ) : (
+                        <svg className="w-4 h-4 ml-0.5" fill="currentColor" viewBox="0 0 24 24"><path d="M8 5v14l11-7z"/></svg>
+                      )}
+                      <span className="absolute -bottom-1 -right-1 text-[8px] font-bold bg-zinc-900 text-white px-1 py-0.5 rounded">
+                        {formatTime(sourceDuration)}
+                      </span>
+                    </button>
+                    <div className="flex-1 min-w-0">
+                      <div className="text-xs font-medium text-zinc-800 dark:text-zinc-200 truncate mb-1.5">
+                        {sourceAudioTitle || getAudioLabel(sourceAudioUrl)}
+                      </div>
+                      <div className="flex items-center gap-2">
+                        <span className="text-[10px] text-zinc-400 tabular-nums">{formatTime(sourceTime)}</span>
+                        <div
+                          className="relative flex-1 h-1.5 rounded-full bg-zinc-200 dark:bg-white/10 cursor-pointer group/seek"
+                          onClick={(e) => {
+                            if (sourceAudioRef.current && sourceDuration > 0) {
+                              const rect = e.currentTarget.getBoundingClientRect();
+                              const percent = (e.clientX - rect.left) / rect.width;
+                              sourceAudioRef.current.currentTime = percent * sourceDuration;
+                            }
+                          }}
+                        >
+                          {/* Repaint region overlay */}
+                          {renderRepaintRegionOverlay()}
+                          <div
+                            className="h-full bg-gradient-to-r from-emerald-500 to-teal-500 rounded-full transition-all relative"
+                            style={{ width: sourceDuration ? `${Math.min(100, (sourceTime / sourceDuration) * 100)}%` : '0%' }}
+                          >
+                            <div className="absolute right-0 top-1/2 -translate-y-1/2 w-2.5 h-2.5 rounded-full bg-white shadow-md opacity-0 group-hover/seek:opacity-100 transition-opacity" />
+                          </div>
+                        </div>
+                        <span className="text-[10px] text-zinc-400 tabular-nums">{formatTime(sourceDuration)}</span>
+                      </div>
+                    </div>
+                    <button
+                      type="button"
+                      onClick={handleClearSourceAudio}
+                      className="p-1.5 rounded-full hover:bg-zinc-200 dark:hover:bg-white/10 text-zinc-400 hover:text-zinc-600 dark:hover:text-white transition-colors"
+                    >
+                      <svg className="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12"/></svg>
+                    </button>
+                  </div>
+                )}
+
+                {/* Cover / Repaint mode controls — shown when source audio is loaded */}
+                {sourceAudioUrl && (
+                  <div className="space-y-2">
+                    {/* Mode toggle */}
+                    <div className="flex items-center gap-1 bg-zinc-100 dark:bg-black/20 rounded-lg p-0.5">
+                      <button
+                        type="button"
+                        onClick={() => setTaskType('cover')}
+                        className={`flex-1 py-1.5 rounded-md text-[11px] font-medium transition-all ${
+                          taskType !== 'repaint'
+                            ? 'bg-white dark:bg-zinc-700 text-zinc-900 dark:text-white shadow-sm'
+                            : 'text-zinc-500 dark:text-zinc-400 hover:text-zinc-700 dark:hover:text-zinc-200'
+                        }`}
+                      >
+                        {t('coverMode')}
+                      </button>
+                      <button
+                        type="button"
+                        onClick={() => setTaskType('repaint')}
+                        className={`flex-1 py-1.5 rounded-md text-[11px] font-medium transition-all ${
+                          taskType === 'repaint'
+                            ? 'bg-white dark:bg-zinc-700 text-zinc-900 dark:text-white shadow-sm'
+                            : 'text-zinc-500 dark:text-zinc-400 hover:text-zinc-700 dark:hover:text-zinc-200'
+                        }`}
+                      >
+                        {t('repaintMode')}
+                      </button>
+                    </div>
+
+                    {/* Mode description */}
+                    <p className="text-[10px] text-zinc-400 dark:text-zinc-500 px-0.5">
+                      {taskType === 'repaint' ? t('repaintModeDescription') : t('coverModeDescription')}
+                    </p>
+
+                    {/* Cover strength slider (cover mode only) */}
+                    {taskType !== 'repaint' && (
+                      <div className="flex items-center gap-2">
+                        <label className="text-[10px] text-zinc-500 dark:text-zinc-400 whitespace-nowrap">{t('audioCoverStrength')}</label>
+                        <input
+                          type="range"
+                          min="0"
+                          max="1"
+                          step="0.05"
+                          value={audioCoverStrength}
+                          onChange={(e) => setAudioCoverStrength(Number(e.target.value))}
+                          className="flex-1 h-1.5 accent-emerald-500"
+                        />
+                        <span className="text-[10px] text-zinc-400 tabular-nums w-7 text-right">{audioCoverStrength.toFixed(2)}</span>
+                      </div>
+                    )}
+
+                    {/* Repaint time range (repaint mode only) */}
+                    {taskType === 'repaint' && (
+                      <div className="grid grid-cols-2 gap-2">
+                        <div className="space-y-1">
+                          <label className="text-[10px] text-zinc-500 dark:text-zinc-400">
+                            {t('repaintStart')}
+                            {sourceDuration > 0 && <span className="text-zinc-400 ml-1">(max {formatTime(sourceDuration)})</span>}
+                          </label>
+                          <input
+                            type="number"
+                            step="0.1"
+                            min="0"
+                            max={sourceDuration > 0 ? sourceDuration : undefined}
+                            placeholder={t('repaintStartPlaceholder')}
+                            value={repaintingStart >= 0 ? repaintingStart : ''}
+                            onChange={(e) => setRepaintingStart(e.target.value === '' ? -1 : Number(e.target.value))}
+                            className="w-full bg-zinc-50 dark:bg-black/20 border border-zinc-200 dark:border-white/10 rounded-lg px-2 py-1.5 text-xs text-zinc-900 dark:text-white focus:outline-none focus:border-emerald-500 dark:focus:border-emerald-500 transition-colors"
+                          />
+                        </div>
+                        <div className="space-y-1">
+                          <label className="text-[10px] text-zinc-500 dark:text-zinc-400">
+                            {t('repaintEnd')}
+                            {sourceDuration > 0 && <span className="text-zinc-400 ml-1">(max {formatTime(sourceDuration)})</span>}
+                          </label>
+                          <input
+                            type="number"
+                            step="0.1"
+                            min="0"
+                            max={sourceDuration > 0 ? sourceDuration : undefined}
+                            placeholder={t('repaintEndPlaceholder')}
+                            value={repaintingEnd >= 0 ? repaintingEnd : ''}
+                            onChange={(e) => setRepaintingEnd(e.target.value === '' ? -1 : Number(e.target.value))}
+                            className="w-full bg-zinc-50 dark:bg-black/20 border border-zinc-200 dark:border-white/10 rounded-lg px-2 py-1.5 text-xs text-zinc-900 dark:text-white focus:outline-none focus:border-emerald-500 dark:focus:border-emerald-500 transition-colors"
+                          />
+                        </div>
+                      </div>
+                    )}
+
+                    {/* SFT model status banner (repaint only) */}
+                    {taskType === 'repaint' && sftStatus !== 'idle' && (
+                      <div className={`flex items-center gap-2 px-3 py-2 rounded-lg text-[11px] font-medium ${
+                        sftStatus === 'available'
+                          ? 'bg-emerald-50 dark:bg-emerald-900/20 text-emerald-700 dark:text-emerald-400'
+                          : sftStatus === 'downloading' || sftStatus === 'checking'
+                          ? 'bg-amber-50 dark:bg-amber-900/20 text-amber-700 dark:text-amber-400'
+                          : 'bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-400'
+                      }`}>
+                        {sftStatus === 'available' && <CheckCircle2 size={13} />}
+                        {(sftStatus === 'downloading' || sftStatus === 'checking') && <Loader2 size={13} className="animate-spin" />}
+                        {sftStatus === 'unavailable' && <AlertTriangle size={13} />}
+                        <span className="flex-1">
+                          {sftStatus === 'available' && t('sftModelReady')}
+                          {sftStatus === 'checking' && t('sftModelRequired')}
+                          {sftStatus === 'downloading' && t('sftModelDownloading')}
+                          {sftStatus === 'unavailable' && t('sftModelNotFound')}
+                        </span>
+                        {sftStatus === 'unavailable' && (
+                          <a
+                            href="/models"
+                            onClick={(e) => { e.preventDefault(); window.history.pushState({}, '', '/models'); window.dispatchEvent(new PopStateEvent('popstate')); }}
+                            className="flex items-center gap-0.5 underline underline-offset-2"
+                          >
+                            Models <ExternalLink size={10} />
+                          </a>
+                        )}
+                      </div>
+                    )}
+                  </div>
+                )}
+
+                {/* Upload / Library buttons */}
+                <div className="flex gap-2">
+                  <button
+                    type="button"
+                    onClick={() => openAudioModal('source', 'uploads')}
+                    className="flex-1 flex items-center justify-center gap-1.5 rounded-lg bg-zinc-100 dark:bg-white/5 hover:bg-zinc-200 dark:hover:bg-white/10 text-zinc-700 dark:text-zinc-300 px-3 py-2 text-xs font-medium transition-colors border border-zinc-200 dark:border-white/5"
+                  >
+                    <svg className="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9 19V6l12-3v13M9 19c0 1.105-1.343 2-3 2s-3-.895-3-2 1.343-2 3-2 3 .895 3 2zm12-3c0 1.105-1.343 2-3 2s-3-.895-3-2 1.343-2 3-2 3 .895 3 2zM9 10l12-3"/>
+                    </svg>
+                    {t('fromLibrary')}
+                  </button>
+                  <button
+                    type="button"
+                    onClick={() => sourceInputRef.current?.click()}
+                    className="flex-1 flex items-center justify-center gap-1.5 rounded-lg bg-zinc-100 dark:bg-white/5 hover:bg-zinc-200 dark:hover:bg-white/10 text-zinc-700 dark:text-zinc-300 px-3 py-2 text-xs font-medium transition-colors border border-zinc-200 dark:border-white/5"
+                  >
+                    <svg className="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12"/>
+                    </svg>
+                    {t('upload')}
+                  </button>
+                </div>
+              </div>
+            </div>
+
             {/* Quick Settings (Simple Mode) */}
             <div className="bg-white dark:bg-suno-card rounded-xl border border-zinc-200 dark:border-white/5 p-4 space-y-4">
               <h3 className="text-xs font-bold text-zinc-500 dark:text-zinc-400 uppercase tracking-wide flex items-center gap-2">
@@ -1486,7 +1829,7 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
                       <div className="flex items-center gap-2">
                         <span className="text-[10px] text-zinc-400 tabular-nums">{formatTime(sourceTime)}</span>
                         <div
-                          className="flex-1 h-1.5 rounded-full bg-zinc-200 dark:bg-white/10 cursor-pointer group/seek"
+                          className="relative flex-1 h-1.5 rounded-full bg-zinc-200 dark:bg-white/10 cursor-pointer group/seek"
                           onClick={(e) => {
                             if (sourceAudioRef.current && sourceDuration > 0) {
                               const rect = e.currentTarget.getBoundingClientRect();
@@ -1495,6 +1838,8 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
                             }
                           }}
                         >
+                          {/* Repaint region overlay */}
+                          {renderRepaintRegionOverlay()}
                           <div
                             className="h-full bg-gradient-to-r from-emerald-500 to-teal-500 rounded-full transition-all relative"
                             style={{ width: sourceDuration ? `${Math.min(100, (sourceTime / sourceDuration) * 100)}%` : '0%' }}
@@ -1507,7 +1852,7 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
                     </div>
                     <button
                       type="button"
-                      onClick={() => { setSourceAudioUrl(''); setSourceAudioTitle(''); setSourcePlaying(false); setSourceTime(0); setSourceDuration(0); }}
+                      onClick={handleClearSourceAudio}
                       className="p-1.5 rounded-full hover:bg-zinc-200 dark:hover:bg-white/10 text-zinc-400 hover:text-zinc-600 dark:hover:text-white transition-colors"
                     >
                       <svg className="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12"/></svg>
@@ -1515,6 +1860,127 @@ export const CreatePanel: React.FC<CreatePanelProps> = ({
                   </div>
                 )}
 
+                {/* Cover / Repaint mode toggle (shown when source audio is loaded) */}
+                {audioTab === 'source' && sourceAudioUrl && (
+                  <div className="space-y-2">
+                    {/* Mode toggle: Cover vs Repaint */}
+                    <div className="flex items-center gap-1 bg-zinc-100 dark:bg-black/20 rounded-lg p-0.5">
+                      <button
+                        type="button"
+                        onClick={() => setTaskType('cover')}
+                        className={`flex-1 py-1.5 rounded-md text-[11px] font-medium transition-all ${
+                          taskType !== 'repaint'
+                            ? 'bg-white dark:bg-zinc-700 text-zinc-900 dark:text-white shadow-sm'
+                            : 'text-zinc-500 dark:text-zinc-400 hover:text-zinc-700 dark:hover:text-zinc-200'
+                        }`}
+                      >
+                        {t('coverMode')}
+                      </button>
+                      <button
+                        type="button"
+                        onClick={() => setTaskType('repaint')}
+                        className={`flex-1 py-1.5 rounded-md text-[11px] font-medium transition-all ${
+                          taskType === 'repaint'
+                            ? 'bg-white dark:bg-zinc-700 text-zinc-900 dark:text-white shadow-sm'
+                            : 'text-zinc-500 dark:text-zinc-400 hover:text-zinc-700 dark:hover:text-zinc-200'
+                        }`}
+                      >
+                        {t('repaintMode')}
+                      </button>
+                    </div>
+
+                    {/* Mode description */}
+                    <p className="text-[10px] text-zinc-400 dark:text-zinc-500 px-0.5">
+                      {taskType === 'repaint' ? t('repaintModeDescription') : t('coverModeDescription')}
+                    </p>
+
+                    {/* Cover strength slider (only in cover mode) */}
+                    {taskType !== 'repaint' && (
+                      <div className="flex items-center gap-2">
+                        <label className="text-[10px] text-zinc-500 dark:text-zinc-400 whitespace-nowrap">{t('audioCoverStrength')}</label>
+                        <input
+                          type="range"
+                          min="0"
+                          max="1"
+                          step="0.05"
+                          value={audioCoverStrength}
+                          onChange={(e) => setAudioCoverStrength(Number(e.target.value))}
+                          className="flex-1 h-1.5 accent-emerald-500"
+                        />
+                        <span className="text-[10px] text-zinc-400 tabular-nums w-7 text-right">{audioCoverStrength.toFixed(2)}</span>
+                      </div>
+                    )}
+
+                    {/* Repaint time range (only in repaint mode) */}
+                    {taskType === 'repaint' && (
+                      <div className="grid grid-cols-2 gap-2">
+                        <div className="space-y-1">
+                          <label className="text-[10px] text-zinc-500 dark:text-zinc-400">
+                            {t('repaintStart')}
+                            {sourceDuration > 0 && <span className="text-zinc-400 ml-1">(max {formatTime(sourceDuration)})</span>}
+                          </label>
+                          <input
+                            type="number"
+                            step="0.1"
+                            min="0"
+                            max={sourceDuration > 0 ? sourceDuration : undefined}
+                            placeholder={t('repaintStartPlaceholder')}
+                            value={repaintingStart >= 0 ? repaintingStart : ''}
+                            onChange={(e) => setRepaintingStart(e.target.value === '' ? -1 : Number(e.target.value))}
+                            className="w-full bg-zinc-50 dark:bg-black/20 border border-zinc-200 dark:border-white/10 rounded-lg px-2 py-1.5 text-xs text-zinc-900 dark:text-white focus:outline-none focus:border-emerald-500 dark:focus:border-emerald-500 transition-colors"
+                          />
+                        </div>
+                        <div className="space-y-1">
+                          <label className="text-[10px] text-zinc-500 dark:text-zinc-400">
+                            {t('repaintEnd')}
+                            {sourceDuration > 0 && <span className="text-zinc-400 ml-1">(max {formatTime(sourceDuration)})</span>}
+                          </label>
+                          <input
+                            type="number"
+                            step="0.1"
+                            min="0"
+                            max={sourceDuration > 0 ? sourceDuration : undefined}
+                            placeholder={t('repaintEndPlaceholder')}
+                            value={repaintingEnd >= 0 ? repaintingEnd : ''}
+                            onChange={(e) => setRepaintingEnd(e.target.value === '' ? -1 : Number(e.target.value))}
+                            className="w-full bg-zinc-50 dark:bg-black/20 border border-zinc-200 dark:border-white/10 rounded-lg px-2 py-1.5 text-xs text-zinc-900 dark:text-white focus:outline-none focus:border-emerald-500 dark:focus:border-emerald-500 transition-colors"
+                          />
+                        </div>
+                      </div>
+                    )}
+
+                    {/* SFT model status banner (shown when repaint mode active) */}
+                    {taskType === 'repaint' && sftStatus !== 'idle' && (
+                      <div className={`flex items-center gap-2 px-3 py-2 rounded-lg text-[11px] font-medium ${
+                        sftStatus === 'available'
+                          ? 'bg-emerald-50 dark:bg-emerald-900/20 text-emerald-700 dark:text-emerald-400'
+                          : sftStatus === 'downloading' || sftStatus === 'checking'
+                          ? 'bg-amber-50 dark:bg-amber-900/20 text-amber-700 dark:text-amber-400'
+                          : 'bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-400'
+                      }`}>
+                        {sftStatus === 'available' && <CheckCircle2 size={13} />}
+                        {(sftStatus === 'downloading' || sftStatus === 'checking') && <Loader2 size={13} className="animate-spin" />}
+                        {sftStatus === 'unavailable' && <AlertTriangle size={13} />}
+                        <span className="flex-1">
+                          {sftStatus === 'available' && t('sftModelReady')}
+                          {sftStatus === 'checking' && t('sftModelRequired')}
+                          {sftStatus === 'downloading' && t('sftModelDownloading')}
+                          {sftStatus === 'unavailable' && t('sftModelNotFound')}
+                        </span>
+                        {sftStatus === 'unavailable' && (
+                          <a
+                            href="/models"
+                            onClick={(e) => { e.preventDefault(); window.history.pushState({}, '', '/models'); window.dispatchEvent(new PopStateEvent('popstate')); }}
+                            className="flex items-center gap-0.5 underline underline-offset-2"
+                          >
+                            Models <ExternalLink size={10} />
+                          </a>
+                        )}
+                      </div>
+                    )}
+                  </div>
+                )}
+
                 {/* Action buttons */}
                 <div className="flex gap-2">
                   <button
diff --git a/i18n/translations.ts b/i18n/translations.ts
index 92ea10d..717471c 100644
--- a/i18n/translations.ts
+++ b/i18n/translations.ts
@@ -385,6 +385,22 @@ export const translations = {
     coverTask: 'Cover',
     repaintTask: 'Repaint',
     
+    // Repaint mode
+    repaintMode: 'Repaint',
+    coverMode: 'Cover',
+    repaintModeDescription: 'Regenerate a time region while preserving the rest',
+    coverModeDescription: 'Transform an existing track into a new style',
+    repaintStart: 'Start (s)',
+    repaintEnd: 'End (s)',
+    repaintStartPlaceholder: '0',
+    repaintEndPlaceholder: 'end of track',
+    sftModelRequired: 'Repaint requires the SFT model',
+    sftModelDownloading: 'Downloading SFT model…',
+    sftModelReady: 'SFT model ready',
+    sftModelNotFound: 'SFT model not found — go to Models to download it',
+    sftModelSwitched: 'Switched to SFT model for repaint',
+    autoSwitchedToSft: 'Auto-switched to SFT model (required for repaint)',
+    
     // Search Page
     searchSongsPlaceholder: 'Search for songs, playlists, creators, or genres',
     songsMatching: 'Songs matching',
@@ -908,6 +924,22 @@ export const translations = {
     coverTask: '翻唱',
     repaintTask: '重绘',
     
+    // Repaint mode
+    repaintMode: '重绘',
+    coverMode: '翻唱',
+    repaintModeDescription: '重新生成时间区域，保留其余部分',
+    coverModeDescription: '将现有曲目转换为新风格',
+    repaintStart: '开始（秒）',
+    repaintEnd: '结束（秒）',
+    repaintStartPlaceholder: '0',
+    repaintEndPlaceholder: '轨道结束',
+    sftModelRequired: '重绘需要 SFT 模型',
+    sftModelDownloading: '正在下载 SFT 模型…',
+    sftModelReady: 'SFT 模型就绪',
+    sftModelNotFound: '未找到 SFT 模型 — 前往模型页面下载',
+    sftModelSwitched: '已切换到 SFT 模型用于重绘',
+    autoSwitchedToSft: '已自动切换到 SFT 模型（重绘所需）',
+    
     // Search Page
     searchSongsPlaceholder: '搜索歌曲、播放列表、创作者或风格',
     songsMatching: '匹配的歌曲',
@@ -1431,6 +1463,22 @@ export const translations = {
     coverTask: 'カバー',
     repaintTask: 'リペイント',
     
+    // Repaint mode
+    repaintMode: 'リペイント',
+    coverMode: 'カバー',
+    repaintModeDescription: '残りを保持しながら時間領域を再生成',
+    coverModeDescription: '既存のトラックを新しいスタイルに変換',
+    repaintStart: '開始（秒）',
+    repaintEnd: '終了（秒）',
+    repaintStartPlaceholder: '0',
+    repaintEndPlaceholder: 'トラック終端',
+    sftModelRequired: 'リペイントには SFT モデルが必要',
+    sftModelDownloading: 'SFT モデルをダウンロード中…',
+    sftModelReady: 'SFT モデル準備完了',
+    sftModelNotFound: 'SFT モデルが見つかりません — モデルページでダウンロード',
+    sftModelSwitched: 'リペイント用に SFT モデルに切り替えました',
+    autoSwitchedToSft: 'SFT モデルに自動切り替え（リペイントに必要）',
+    
     // Search Page
     searchSongsPlaceholder: '曲、プレイリスト、クリエイター、スタイルを検索',
     songsMatching: '一致する曲',
@@ -1954,6 +2002,22 @@ export const translations = {
     coverTask: '커버',
     repaintTask: '리페인트',
     
+    // Repaint mode
+    repaintMode: '리페인트',
+    coverMode: '커버',
+    repaintModeDescription: '나머지를 유지하면서 시간 영역을 재생성',
+    coverModeDescription: '기존 트랙을 새로운 스타일로 변환',
+    repaintStart: '시작 (초)',
+    repaintEnd: '종료 (초)',
+    repaintStartPlaceholder: '0',
+    repaintEndPlaceholder: '트랙 끝',
+    sftModelRequired: '리페인트에는 SFT 모델이 필요합니다',
+    sftModelDownloading: 'SFT 모델 다운로드 중…',
+    sftModelReady: 'SFT 모델 준비 완료',
+    sftModelNotFound: 'SFT 모델을 찾을 수 없습니다 — 모델 페이지에서 다운로드하세요',
+    sftModelSwitched: '리페인트를 위해 SFT 모델로 전환했습니다',
+    autoSwitchedToSft: 'SFT 모델로 자동 전환됨 (리페인트에 필요)',
+    
     // Search Page
     searchSongsPlaceholder: '곡, 재생목록, 제작자 또는 스타일 검색',
     songsMatching: '일치하는 곡',
diff --git a/server/src/services/acestep.ts b/server/src/services/acestep.ts
index 8140b36..01ca9f2 100644
--- a/server/src/services/acestep.ts
+++ b/server/src/services/acestep.ts
@@ -134,13 +134,13 @@ let isProcessingQueue = false;
  * Returns true when the spawn-mode binaries satisfy the requirements for
  * the given generation parameters.
  *
- * - Cover/passthrough (sourceAudioUrl or audioCodes): only dit-vae is needed;
- *   ace-qwen3 is skipped because the audio codes come from the source audio.
+ * - Cover/repaint/passthrough (sourceAudioUrl or audioCodes): only dit-vae is needed;
+ *   ace-qwen3 is skipped because the audio is derived from the source audio or codes.
  * - Text-to-music: both ace-qwen3 (LLM) and dit-vae (synthesis) are required.
  */
 function useSpawnMode(params?: Pick<GenerationParams, 'sourceAudioUrl' | 'audioCodes'>): boolean {
   if (!config.acestep.ditVaeBin) return false;
-  // Cover / passthrough: only dit-vae is needed — no LLM step
+  // Cover / repaint / passthrough: only dit-vae is needed — no LLM step
   if (params?.sourceAudioUrl || params?.audioCodes) return true;
   // Text-to-music: need ace-qwen3 too
   return Boolean(config.acestep.lmBin);
@@ -478,7 +478,17 @@ async function runViaSpawn(
     // Passthrough: skip the LLM when audio codes are already provided
     if (params.audioCodes)                requestJson.audio_codes   = params.audioCodes;
     // Cover/audio-to-audio: strength of the source audio influence on the output
-    if (params.audioCoverStrength !== undefined) requestJson.audio_cover_strength = params.audioCoverStrength;
+    // (ignored in repaint mode — the mask handles everything)
+    if (params.audioCoverStrength !== undefined && params.taskType !== 'repaint') {
+      requestJson.audio_cover_strength = params.audioCoverStrength;
+    }
+    // Repaint mode: regenerate a time region while preserving the rest.
+    // Activated by setting repainting_start and/or repainting_end in the JSON.
+    // Both default to -1 (inactive): -1 on start means 0s, -1 on end means source duration.
+    if (params.taskType === 'repaint' && params.sourceAudioUrl) {
+      requestJson.repainting_start = params.repaintingStart ?? -1;
+      requestJson.repainting_end   = params.repaintingEnd   ?? -1;
+    }
 
     const requestPath = path.join(tmpDir, 'request.json');
     await writeFile(requestPath, JSON.stringify(requestJson, null, 2));
@@ -840,6 +850,12 @@ async function processGeneration(
     return;
   }
 
+  if (params.taskType === 'repaint' && !params.sourceAudioUrl) {
+    job.status = 'failed';
+    job.error  = "task_type='repaint' requires a source audio (--src-audio)";
+    return;
+  }
+
   try {
     job.stage = 'Generating music...';
     if (useSpawnMode(params)) {