diff --git a/backend/utils/airdrama_client.py b/backend/utils/airdrama_client.py
index 63e05a9..4bcef4c 100644
--- a/backend/utils/airdrama_client.py
+++ b/backend/utils/airdrama_client.py
@@ -9,6 +9,7 @@ ERROR_MESSAGES = {
     # Input content moderation — 人脸/敏感内容
     'InputImageSensitiveContentDetected.PrivacyInformation': '参考图片中检测到真实人脸，请使用虚拟人像素材替代真人照片',
     'InputImageSensitiveContentDetected': '参考图片包含敏感内容，请更换图片后重试',
+    'InputVideoSensitiveContentDetected.PrivacyInformation': '参考视频中检测到真实人脸，请使用虚拟人像素材替代真人视频',
     'InputVideoSensitiveContentDetected': '参考视频包含敏感内容，请更换视频后重试',
     'InputTextSensitiveContentDetected': '提示词包含敏感内容，请修改后重试',
     'InputAudioSensitiveContentDetected': '参考音频包含敏感内容，请更换音频后重试',
diff --git a/web/src/components/AssetLibraryModal.module.css b/web/src/components/AssetLibraryModal.module.css
index 41177d9..c7e85b8 100644
--- a/web/src/components/AssetLibraryModal.module.css
+++ b/web/src/components/AssetLibraryModal.module.css
@@ -11,12 +11,11 @@
 .modal {
   width: 90vw;
   max-width: 1400px;
-  min-height: 85vh;
-  max-height: 92vh;
+  height: 85vh;
   background: #16161e;
   border: 1px solid var(--color-border-card);
   border-radius: 12px;
-  overflow-y: auto;
+  overflow: hidden;
   display: flex;
   flex-direction: column;
 }
diff --git a/web/src/components/AssetLibraryModal.tsx b/web/src/components/AssetLibraryModal.tsx
index e1f10ef..ce9c28e 100644
--- a/web/src/components/AssetLibraryModal.tsx
+++ b/web/src/components/AssetLibraryModal.tsx
@@ -1,7 +1,8 @@
 import { useState, useEffect, useRef, useCallback } from 'react';
 import { useAssetLibraryStore } from '../store/assetLibrary';
-import { assetsApi } from '../lib/api';
+import { assetsApi, tosThumb } from '../lib/api';
 import { showToast } from './Toast';
+import { ImageLightbox } from './ImageLightbox';
 import type { AssetGroup, AssetItem } from '../types';
 import styles from './AssetLibraryModal.module.css';
 
@@ -20,6 +21,7 @@ export function AssetLibraryModal({ open, onClose }: Props) {
   const [uploadFile, setUploadFile] = useState<File | null>(null);
   const [uploadPreview, setUploadPreview] = useState<string | null>(null);
   const [dragOver, setDragOver] = useState(false);
+  const [lightboxSrc, setLightboxSrc] = useState<string | null>(null);
   const fileInputRef = useRef<HTMLInputElement>(null);
   const addFileInputRef = useRef<HTMLInputElement>(null);
 
@@ -209,7 +211,7 @@ export function AssetLibraryModal({ open, onClose }: Props) {
                 <div className={styles.grid}>
                   {groups.map((group) => (
                     <div key={group.id} className={styles.card} onClick={() => handleGroupClick(group)}>
-                      <img src={group.thumbnail_url} alt={group.name} className={styles.cardThumb} />
+                      <img src={tosThumb(group.thumbnail_url, 300)} alt={group.name} className={styles.cardThumb} />
                       <div className={styles.cardInfo}>
                         {editingName && editingName.id === group.id ? (
                           <div className={styles.inlineEditWrap} onClick={(e) => e.stopPropagation()}>
@@ -342,7 +344,13 @@ export function AssetLibraryModal({ open, onClose }: Props) {
                 <div className={styles.assetGrid}>
                   {groupAssets.map((asset) => (
                     <div key={asset.id} className={styles.assetCard}>
-                      <img src={asset.url} alt={asset.name} className={styles.assetThumb} />
+                      <img
+                        src={tosThumb(asset.url, 300)}
+                        alt={asset.name}
+                        className={styles.assetThumb}
+                        style={{ cursor: 'zoom-in' }}
+                        onClick={() => setLightboxSrc(asset.url)}
+                      />
                       <div className={styles.assetInfo}>
                         <div className={styles.assetName}>{asset.name}</div>
                         <span className={`${styles.statusBadge} ${
@@ -423,6 +431,7 @@ export function AssetLibraryModal({ open, onClose }: Props) {
           )}
         </div>
       </div>
+      <ImageLightbox src={lightboxSrc} onClose={() => setLightboxSrc(null)} />
     </div>
   );
 }
diff --git a/web/src/components/GenerationCard.tsx b/web/src/components/GenerationCard.tsx
index 4dc743e..65da072 100644
--- a/web/src/components/GenerationCard.tsx
+++ b/web/src/components/GenerationCard.tsx
@@ -4,6 +4,7 @@ import type { GenerationTask } from '../types';
 import { useGenerationStore } from '../store/generation';
 import { showToast } from './Toast';
 import { ConfirmModal } from './ConfirmModal';
+import { tosThumb } from '../lib/api';
 import styles from './GenerationCard.module.css';
 
 const EditIcon = () => (
@@ -57,7 +58,7 @@ function MentionTag({ label, thumbUrl }: { label: string; thumbUrl?: string }) {
       >
         {thumbUrl && (
           <img
-            src={thumbUrl}
+            src={tosThumb(thumbUrl, 28)}
             alt=""
             style={{ width: 14, height: 14, borderRadius: 3, objectFit: 'cover', verticalAlign: 'middle', marginRight: 3 }}
           />
@@ -66,7 +67,7 @@ function MentionTag({ label, thumbUrl }: { label: string; thumbUrl?: string }) {
       </span>
       {hover && thumbUrl && createPortal(
         <div className={styles.mentionPreview} style={{ top: pos.top, left: pos.left }}>
-          <img src={thumbUrl} alt={label} className={styles.mentionPreviewImg} />
+          <img src={tosThumb(thumbUrl, 200)} alt={label} className={styles.mentionPreviewImg} />
           <div className={styles.mentionPreviewLabel}>{label}</div>
         </div>,
         document.body
@@ -137,6 +138,7 @@ export function GenerationCard({ task, onOpenDetail }: Props) {
   const [detailPos, setDetailPos] = useState({ top: 0, right: 0 });
   const detailLinkRef = useRef<HTMLSpanElement>(null);
   const detailLeaveTimer = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const [refPreview, setRefPreview] = useState<{ url: string; label: string; type: string; top: number; left: number } | null>(null);
 
   const startDetailLeave = useCallback(() => {
     if (detailLeaveTimer.current) clearTimeout(detailLeaveTimer.current);
@@ -272,7 +274,16 @@ export function GenerationCard({ task, onOpenDetail }: Props) {
         {task.references.length > 0 && (
           <div ref={refColumnRef} className={styles.refColumn}>
             {task.references.map((ref) => (
-              <div key={ref.id} className={styles.refThumb}>
+              <div
+                key={ref.id}
+                className={styles.refThumb}
+                onMouseEnter={(e) => {
+                  if (ref.type === 'audio') return;
+                  const rect = e.currentTarget.getBoundingClientRect();
+                  setRefPreview({ url: ref.previewUrl, label: ref.label, type: ref.type, top: rect.top - 8, left: rect.left + rect.width / 2 });
+                }}
+                onMouseLeave={() => setRefPreview(null)}
+              >
                 {ref.type === 'video' ? (
                   <video src={ref.previewUrl} className={styles.refMedia} muted />
                 ) : ref.type === 'audio' ? (
@@ -284,7 +295,7 @@ export function GenerationCard({ task, onOpenDetail }: Props) {
                     </svg>
                   </div>
                 ) : (
-                  <img src={ref.previewUrl} alt={ref.label} className={styles.refMedia} />
+                  <img src={tosThumb(ref.previewUrl, 112)} alt={ref.label} className={styles.refMedia} />
                 )}
               </div>
             ))}
@@ -387,6 +398,19 @@ export function GenerationCard({ task, onOpenDetail }: Props) {
         )}
       </div>
 
+      {/* Reference thumbnail hover preview */}
+      {refPreview && createPortal(
+        <div className={styles.mentionPreview} style={{ top: refPreview.top, left: refPreview.left }}>
+          {refPreview.type === 'video' ? (
+            <video src={refPreview.url} className={styles.mentionPreviewImg} autoPlay loop muted playsInline />
+          ) : (
+            <img src={tosThumb(refPreview.url, 300)} alt={refPreview.label} className={styles.mentionPreviewImg} />
+          )}
+          <div className={styles.mentionPreviewLabel}>{refPreview.label}</div>
+        </div>,
+        document.body
+      )}
+
       {/* Video / result area */}
       <div className={styles.content}>
         {isGenerating ? (
diff --git a/web/src/components/PromptInput.tsx b/web/src/components/PromptInput.tsx
index b387b8b..4f15211 100644
--- a/web/src/components/PromptInput.tsx
+++ b/web/src/components/PromptInput.tsx
@@ -1,7 +1,7 @@
 import { useRef, useEffect, useCallback, useState } from 'react';
 import DOMPurify from 'dompurify';
 import { useInputBarStore } from '../store/inputBar';
-import { assetsApi } from '../lib/api';
+import { assetsApi, tosThumb } from '../lib/api';
 import type { UploadedFile, AssetGroup } from '../types';
 import styles from './PromptInput.module.css';
 
@@ -77,7 +77,7 @@ export function PromptInput() {
 
     if (opts.thumbUrl) {
       const img = document.createElement('img');
-      img.src = opts.thumbUrl;
+      img.src = tosThumb(opts.thumbUrl, 32);
       img.className = styles.mentionImg;
       // 显式设置尺寸，防止 CSS class 未生效时图片为 0x0
       img.setAttribute('width', '16');
@@ -253,6 +253,12 @@ export function PromptInput() {
     const textBeforeCursor = text.substring(0, offset);
     const lastAtIdx = textBeforeCursor.lastIndexOf('@');
 
+    if (lastAtIdx < 0) {
+      // No @ before cursor, close popup
+      setShowMentionPopup(false);
+      return;
+    }
+
     if (lastAtIdx >= 0) {
       const textAfterAt = textBeforeCursor.substring(lastAtIdx + 1);
 
@@ -604,7 +610,7 @@ export function PromptInput() {
                     {ref.type === 'video' ? (
                       <video src={ref.previewUrl} muted className={styles.thumbMedia} />
                     ) : (
-                      <img src={ref.previewUrl} alt="" className={styles.thumbMedia} />
+                      <img src={tosThumb(ref.previewUrl, 72)} alt="" className={styles.thumbMedia} />
                     )}
                   </div>
                   <span className={styles.mentionLabel}>{ref.label}</span>
@@ -628,7 +634,7 @@ export function PromptInput() {
                   }}
                 >
                   <div className={styles.mentionThumb}>
-                    <img src={group.thumbnail_url} alt="" className={styles.thumbMedia} />
+                    <img src={tosThumb(group.thumbnail_url, 72)} alt="" className={styles.thumbMedia} />
                   </div>
                   <span className={styles.mentionLabel}>{group.name}</span>
                   <span className={styles.mentionType}>人像</span>
@@ -656,7 +662,7 @@ export function PromptInput() {
             />
           ) : (
             <img
-              src={hoverRef.previewUrl}
+              src={tosThumb(hoverRef.previewUrl, 200)}
               alt={hoverRef.label}
               className={styles.previewMedia}
             />
diff --git a/web/src/components/UniversalUpload.tsx b/web/src/components/UniversalUpload.tsx
index f598f34..2804955 100644
--- a/web/src/components/UniversalUpload.tsx
+++ b/web/src/components/UniversalUpload.tsx
@@ -2,6 +2,7 @@ import { useRef, useState } from 'react';
 import { useInputBarStore } from '../store/inputBar';
 import { showToast } from './Toast';
 import { ImageLightbox } from './ImageLightbox';
+import { tosThumb } from '../lib/api';
 import styles from './UniversalUpload.module.css';
 
 const MAX_IMAGE_SIZE = 30 * 1024 * 1024;  // 30MB per API doc
@@ -124,7 +125,7 @@ export function UniversalUpload() {
                       <AudioIcon />
                     </div>
                   ) : (
-                    <img src={ref.previewUrl} alt={ref.label} className={styles.thumbMedia} style={{ cursor: 'zoom-in' }} onClick={(e) => { e.stopPropagation(); setLightboxSrc(ref.previewUrl); }} />
+                    <img src={tosThumb(ref.previewUrl, 200)} alt={ref.label} className={styles.thumbMedia} style={{ cursor: 'zoom-in' }} onClick={(e) => { e.stopPropagation(); setLightboxSrc(ref.previewUrl); }} />
                   )}
                   <div
                     className={styles.thumbClose}
diff --git a/web/src/components/VideoDetailModal.tsx b/web/src/components/VideoDetailModal.tsx
index 8b57bcf..dbb0952 100644
--- a/web/src/components/VideoDetailModal.tsx
+++ b/web/src/components/VideoDetailModal.tsx
@@ -6,6 +6,7 @@ import { ConfirmModal } from './ConfirmModal';
 import { ImageLightbox } from './ImageLightbox';
 import { useInputBarStore } from '../store/inputBar';
 import { renderPromptWithMentions } from './GenerationCard';
+import { tosThumb } from '../lib/api';
 import styles from './VideoDetailModal.module.css';
 
 interface Props {
@@ -488,7 +489,7 @@ export function VideoDetailModal({ task, onClose, onReEdit, onRegenerate, onDele
                           </svg>
                         </div>
                       ) : (
-                        <img src={ref.previewUrl} alt={ref.label} className={styles.refImg} style={{ cursor: 'zoom-in' }} onClick={() => setLightboxSrc(ref.previewUrl)} />
+                        <img src={tosThumb(ref.previewUrl, 300)} alt={ref.label} className={styles.refImg} style={{ cursor: 'zoom-in' }} onClick={() => setLightboxSrc(ref.previewUrl)} />
                       )}
                       <span className={styles.refLabel}>{ref.label}</span>
                     </div>
diff --git a/web/src/lib/api.ts b/web/src/lib/api.ts
index c9d4e6b..abc7f04 100644
--- a/web/src/lib/api.ts
+++ b/web/src/lib/api.ts
@@ -387,4 +387,17 @@ export const assetsApi = {
     api.get<{ id: number; status: string; url: string; error_message: string }>(`/assets/${id}/status`),
 };
 
+/**
+ * Append TOS image resize parameter to reduce loading size.
+ * Only applies to TOS image URLs (volces.com with image extensions).
+ */
+export function tosThumb(url: string | undefined, height: number): string {
+  if (!url) return '';
+  // 只对我们自己的 TOS 桶生效（airdrama-media），不处理火山内部桶（ark-media-asset 等）
+  if (!url.includes('airdrama-media')) return url;
+  if (!/\.(png|jpg|jpeg|webp|gif)/i.test(url)) return url;
+  const sep = url.includes('?') ? '&' : '?';
+  return `${url}${sep}x-tos-process=image/resize,h_${height}`;
+}
+
 export default api;