diff --git a/src/web-ui/src/app/components/panels/FilesPanel.tsx b/src/web-ui/src/app/components/panels/FilesPanel.tsx
index bd28fbebb7..fe32f84aa6 100644
--- a/src/web-ui/src/app/components/panels/FilesPanel.tsx
+++ b/src/web-ui/src/app/components/panels/FilesPanel.tsx
@@ -1369,6 +1369,7 @@ const FilesPanel: React.FC<FilesPanelProps> = ({
           const siblingNames = getChildNames(fileTree, inputDialog.parentPath);
           const errorKey = validateFileName(value, {
             isRemote: isRemoteCurrentWorkspace,
+            isDirectory: inputDialog.type === 'newFolder',
             siblings: siblingNames,
           });
           return errorKey ? t(errorKey, { name: value.trim() }) : null;
diff --git a/src/web-ui/src/component-library/components/ConfirmDialog/ConfirmDialog.scss b/src/web-ui/src/component-library/components/ConfirmDialog/ConfirmDialog.scss
index 19e8d38dfb..45ba7e3be9 100644
--- a/src/web-ui/src/component-library/components/ConfirmDialog/ConfirmDialog.scss
+++ b/src/web-ui/src/component-library/components/ConfirmDialog/ConfirmDialog.scss
@@ -74,6 +74,9 @@
     line-height: 1.55;
     color: var(--color-text-secondary);
     text-align: left;
+    white-space: normal;
+    overflow-wrap: anywhere;
+    word-break: break-word;
 
     > *:first-child {
       margin-top: 0;
diff --git a/src/web-ui/src/component-library/components/Modal/Modal.test.tsx b/src/web-ui/src/component-library/components/Modal/Modal.test.tsx
index 40c50356c1..f57e647e8e 100644
--- a/src/web-ui/src/component-library/components/Modal/Modal.test.tsx
+++ b/src/web-ui/src/component-library/components/Modal/Modal.test.tsx
@@ -90,6 +90,35 @@ describe('Modal behavior', () => {
     expect(document.body.querySelector('.modal--exiting')).toBeNull();
   });
 
+  it('closes only when the pointer press and release both occur on the overlay', () => {
+    const onClose = vi.fn();
+    act(() => {
+      root.render(
+        <Modal isOpen onClose={onClose} title="Overlay behavior">
+          <input defaultValue="Selectable content" />
+        </Modal>,
+      );
+    });
+
+    const overlay = document.body.querySelector('.modal-overlay') as HTMLDivElement;
+    const input = document.body.querySelector('.modal input') as HTMLInputElement;
+
+    act(() => {
+      overlay.dispatchEvent(new MouseEvent('mousedown', { bubbles: true }));
+      overlay.dispatchEvent(new MouseEvent('mouseup', { bubbles: true }));
+      overlay.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+    });
+    expect(onClose).toHaveBeenCalledTimes(1);
+
+    onClose.mockClear();
+    act(() => {
+      input.dispatchEvent(new MouseEvent('mousedown', { bubbles: true }));
+      overlay.dispatchEvent(new MouseEvent('mouseup', { bubbles: true }));
+      overlay.dispatchEvent(new MouseEvent('click', { bubbles: true }));
+    });
+    expect(onClose).not.toHaveBeenCalled();
+  });
+
   it('closes a standalone modal on Escape', () => {
     const onClose = vi.fn();
     act(() => {
diff --git a/src/web-ui/src/component-library/components/Modal/Modal.tsx b/src/web-ui/src/component-library/components/Modal/Modal.tsx
index 6ea7099b26..c4d2b17dd9 100644
--- a/src/web-ui/src/component-library/components/Modal/Modal.tsx
+++ b/src/web-ui/src/component-library/components/Modal/Modal.tsx
@@ -145,6 +145,7 @@ export const Modal: React.FC<ModalProps> = ({
   const [resizeStart, setResizeStart] = useState({ x: 0, y: 0, width: 0, height: 0 });
   const modalRef = useRef<HTMLDivElement>(null);
   const headerRef = useRef<HTMLDivElement>(null);
+  const overlayPointerDownRef = useRef(false);
   const previousFocusRef = useRef<HTMLElement | null>(null);
   const onCloseRef = useRef(onClose);
   const generatedTitleId = useId();
@@ -230,6 +231,20 @@ export const Modal: React.FC<ModalProps> = ({
     };
   }, [isOpen]);
 
+  const handleOverlayMouseDown = useCallback((event: React.MouseEvent<HTMLDivElement>) => {
+    overlayPointerDownRef.current = event.target === event.currentTarget;
+  }, []);
+
+  const handleOverlayClick = useCallback((event: React.MouseEvent<HTMLDivElement>) => {
+    const startedAndEndedOnOverlay =
+      overlayPointerDownRef.current && event.target === event.currentTarget;
+    overlayPointerDownRef.current = false;
+
+    if (!isExiting && closeOnOverlayClick && startedAndEndedOnOverlay) {
+      onClose();
+    }
+  }, [closeOnOverlayClick, isExiting, onClose]);
+
   const handleMouseDown = useCallback((e: React.MouseEvent) => {
     if (!draggable || !modalRef.current || !headerRef.current) return;
     
@@ -414,7 +429,8 @@ export const Modal: React.FC<ModalProps> = ({
       ]
         .filter(Boolean)
         .join(' ')}
-      onClick={!isExiting && closeOnOverlayClick ? onClose : undefined}
+      onMouseDown={handleOverlayMouseDown}
+      onClick={handleOverlayClick}
     >
       <div
         ref={modalRef}
diff --git a/src/web-ui/src/locales/en-US/panels/files.json b/src/web-ui/src/locales/en-US/panels/files.json
index 8954202693..02a9567e1a 100644
--- a/src/web-ui/src/locales/en-US/panels/files.json
+++ b/src/web-ui/src/locales/en-US/panels/files.json
@@ -110,6 +110,7 @@
   },
   "validation": {
     "invalidFilename": "File name contains invalid characters",
+    "invalidFolderName": "Folder name contains invalid characters",
     "emptyName": "Type a name",
     "duplicateName": "A file or folder with the name \"{{name}}\" already exists",
     "reservedName": "This name is a reserved device name",
diff --git a/src/web-ui/src/locales/zh-CN/panels/files.json b/src/web-ui/src/locales/zh-CN/panels/files.json
index a88c6593fc..d4c88745f0 100644
--- a/src/web-ui/src/locales/zh-CN/panels/files.json
+++ b/src/web-ui/src/locales/zh-CN/panels/files.json
@@ -110,6 +110,7 @@
   },
   "validation": {
     "invalidFilename": "文件名包含非法字符",
+    "invalidFolderName": "文件夹名包含非法字符",
     "emptyName": "请输入名称",
     "duplicateName": "名为 \"{{name}}\" 的文件或文件夹已存在",
     "reservedName": "该名称是系统保留名",
diff --git a/src/web-ui/src/locales/zh-TW/panels/files.json b/src/web-ui/src/locales/zh-TW/panels/files.json
index bdf83d818d..ba8af2f6dc 100644
--- a/src/web-ui/src/locales/zh-TW/panels/files.json
+++ b/src/web-ui/src/locales/zh-TW/panels/files.json
@@ -110,6 +110,7 @@
   },
   "validation": {
     "invalidFilename": "檔案名包含非法字符",
+    "invalidFolderName": "資料夾名包含非法字符",
     "emptyName": "請輸入名稱",
     "duplicateName": "名為 \"{{name}}\" 的檔案或資料夾已存在",
     "reservedName": "該名稱是系統保留名",
diff --git a/src/web-ui/src/shared/notification-system/services/NotificationService.test.ts b/src/web-ui/src/shared/notification-system/services/NotificationService.test.ts
new file mode 100644
index 0000000000..abc7a80ad5
--- /dev/null
+++ b/src/web-ui/src/shared/notification-system/services/NotificationService.test.ts
@@ -0,0 +1,30 @@
+import { afterEach, describe, expect, it, vi } from 'vitest';
+import { notificationStore } from '../store/NotificationStore';
+import { notificationService } from './NotificationService';
+
+describe('NotificationService error toast', () => {
+  afterEach(() => {
+    vi.useRealTimers();
+    notificationService.dismissAll();
+  });
+
+  it('uses the default toast duration and closes automatically', () => {
+    vi.useFakeTimers();
+    const id = notificationService.error('Failed');
+
+    expect(notificationStore.getState().activeNotifications.some((item) => item.id === id)).toBe(true);
+
+    vi.advanceTimersByTime(notificationStore.getState().config.defaultDuration);
+
+    expect(notificationStore.getState().activeNotifications.some((item) => item.id === id)).toBe(false);
+  });
+
+  it('remains open when duration is explicitly zero', () => {
+    vi.useFakeTimers();
+    const id = notificationService.error('Failed', { duration: 0 });
+
+    vi.advanceTimersByTime(notificationStore.getState().config.defaultDuration * 2);
+
+    expect(notificationStore.getState().activeNotifications.some((item) => item.id === id)).toBe(true);
+  });
+});
diff --git a/src/web-ui/src/shared/notification-system/services/NotificationService.ts b/src/web-ui/src/shared/notification-system/services/NotificationService.ts
index 8debef125e..8c7af57a04 100644
--- a/src/web-ui/src/shared/notification-system/services/NotificationService.ts
+++ b/src/web-ui/src/shared/notification-system/services/NotificationService.ts
@@ -34,10 +34,7 @@ class NotificationService {
 
    
   error(message: string, options?: ToastOptions): string {
-    return this.toast('error', message, {
-      ...options,
-      duration: options?.duration ?? 0
-    });
+    return this.toast('error', message, options);
   }
 
    
diff --git a/src/web-ui/src/tools/file-system/components/FileTreeItem.tsx b/src/web-ui/src/tools/file-system/components/FileTreeItem.tsx
index 2f19bfdd00..bb5faf00a1 100644
--- a/src/web-ui/src/tools/file-system/components/FileTreeItem.tsx
+++ b/src/web-ui/src/tools/file-system/components/FileTreeItem.tsx
@@ -1,6 +1,6 @@
 import React, { useEffect, useLayoutEffect, useRef, useState } from 'react';
 import { createPortal } from 'react-dom';
-import { ChevronRight, ChevronDown, FolderOpen, FileText, Loader2 } from 'lucide-react';
+import { ChevronRight, ChevronDown, FolderOpen, FileText } from 'lucide-react';
 import { Input } from '../../../component-library/components/Input';
 import { dragManager } from '../../../shared/services/DragManager';
 import { fileTreeDragSource } from '../../../shared/context-system/drag-drop/FileTreeDragSource';
@@ -40,6 +40,7 @@ const RenameInput: React.FC<RenameInputProps> = ({ node, siblings, isRemote, onR
   const submittedRef = React.useRef(false);
   const inputRef = useRef<HTMLInputElement>(null);
   const wrapperRef = useRef<HTMLDivElement>(null);
+  const errorRef = useRef<HTMLDivElement>(null);
   const [errorPos, setErrorPos] = useState<{ top: number; left: number } | null>(null);
 
   // 聚焦并选中名称主体（文件去掉扩展名，目录全选）。
@@ -63,7 +64,11 @@ const RenameInput: React.FC<RenameInputProps> = ({ node, siblings, isRemote, onR
   }, [node.name, node.isDirectory]);
 
   const validate = (nextValue: string): string | null => {
-    const errorKey = validateFileName(nextValue, { isRemote, siblings });
+    const errorKey = validateFileName(nextValue, {
+      isRemote,
+      isDirectory: node.isDirectory,
+      siblings,
+    });
     return errorKey ? t(errorKey, { name: nextValue.trim() }) : null;
   };
 
@@ -139,15 +144,20 @@ const RenameInput: React.FC<RenameInputProps> = ({ node, siblings, isRemote, onR
     }
 
     const rect = inputRef.current.getBoundingClientRect();
-    const bubbleHeight = 28; // 浮层预估高度（单行）
+    const bubbleRect = errorRef.current?.getBoundingClientRect();
+    const bubbleHeight = bubbleRect?.height ?? 28;
+    const bubbleWidth = bubbleRect?.width ?? Math.min(280, window.innerWidth - 16);
     const spaceBelow = window.innerHeight - rect.bottom;
     const flip = spaceBelow < bubbleHeight + ERROR_OFFSET;
+    const nextPos = {
+      top: Math.max(8, flip ? rect.top - bubbleHeight - ERROR_OFFSET : rect.bottom + ERROR_OFFSET),
+      left: Math.max(8, Math.min(rect.left, window.innerWidth - bubbleWidth - 8)),
+    };
 
-    setErrorPos({
-      top: flip ? rect.top - bubbleHeight - ERROR_OFFSET : rect.bottom + ERROR_OFFSET,
-      left: rect.left,
-    });
-  }, [error, value]);
+    if (errorPos?.top !== nextPos.top || errorPos.left !== nextPos.left) {
+      setErrorPos(nextPos);
+    }
+  }, [error, value, errorPos]);
 
   // 窗口尺寸变化时重算气泡位置。
   useEffect(() => {
@@ -163,6 +173,7 @@ const RenameInput: React.FC<RenameInputProps> = ({ node, siblings, isRemote, onR
     ? createPortal(
         <div
           className="bitfun-file-explorer__rename-error"
+          ref={errorRef}
           style={{ top: errorPos.top, left: errorPos.left }}
           role="alert"
         >
@@ -221,7 +232,6 @@ export const FileTreeItem: React.FC<FileTreeItemProps> = ({
   indentPx,
   isSelected = false,
   isExpanded = false,
-  isLoading = false,
   className = '',
   renamingPath,
   onRename,
@@ -311,9 +321,7 @@ export const FileTreeItem: React.FC<FileTreeItemProps> = ({
     >
       {node.isDirectory ? (
         <span className={`bitfun-file-explorer__expand-icon ${isExpanded ? 'bitfun-file-explorer__expand-icon--expanded' : ''}`} onClick={handleExpandClick}>
-          {isLoading ? (
-            <Loader2 size={16} className="bitfun-file-explorer__loading-icon" />
-          ) : isExpanded ? (
+          {isExpanded ? (
             <ChevronDown size={16} />
           ) : (
             <ChevronRight size={16} />
diff --git a/src/web-ui/src/tools/file-system/styles/FileExplorer.scss b/src/web-ui/src/tools/file-system/styles/FileExplorer.scss
index bf7875b4e1..af8112db19 100644
--- a/src/web-ui/src/tools/file-system/styles/FileExplorer.scss
+++ b/src/web-ui/src/tools/file-system/styles/FileExplorer.scss
@@ -353,7 +353,7 @@ $_indent-width: 8px;
 .bitfun-file-explorer__rename-error {
   position: fixed;
   z-index: 10000;
-  max-width: 280px;
+  max-width: min(280px, calc(100vw - 16px));
   padding: 4px 8px;
   border-radius: 4px;
   background: var(--color-overlay-black-80, rgba(0, 0, 0, 0.8));
@@ -362,9 +362,9 @@ $_indent-width: 8px;
   line-height: 1.4;
   box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
   pointer-events: none;
-  white-space: nowrap;
-  overflow: hidden;
-  text-overflow: ellipsis;
+  white-space: normal;
+  overflow-wrap: anywhere;
+  word-break: break-word;
 }
 
 .bitfun-file-explorer__compressed-path {
diff --git a/src/web-ui/src/tools/file-system/utils/validateFileName.test.ts b/src/web-ui/src/tools/file-system/utils/validateFileName.test.ts
new file mode 100644
index 0000000000..68ed82ae4b
--- /dev/null
+++ b/src/web-ui/src/tools/file-system/utils/validateFileName.test.ts
@@ -0,0 +1,23 @@
+import { describe, expect, it } from 'vitest';
+import { validateFileName } from './validateFileName';
+
+describe('validateFileName', () => {
+  it('uses distinct invalid-character errors for files and folders', () => {
+    expect(validateFileName('invalid:name', { isRemote: false })).toBe(
+      'validation.invalidFilename',
+    );
+    expect(
+      validateFileName('invalid:name', { isRemote: false, isDirectory: true }),
+    ).toBe('validation.invalidFolderName');
+  });
+
+  it('reports duplicate names without losing the shared file/folder error', () => {
+    expect(
+      validateFileName('README.md', {
+        isRemote: false,
+        isDirectory: false,
+        siblings: ['readme.md'],
+      }),
+    ).toBe('validation.duplicateName');
+  });
+});
diff --git a/src/web-ui/src/tools/file-system/utils/validateFileName.ts b/src/web-ui/src/tools/file-system/utils/validateFileName.ts
index 541f27def7..34db749fdb 100644
--- a/src/web-ui/src/tools/file-system/utils/validateFileName.ts
+++ b/src/web-ui/src/tools/file-system/utils/validateFileName.ts
@@ -22,6 +22,8 @@ export const MAX_NAME_LENGTH = 255;
 export interface ValidateFileNameContext {
   /** 当前是否为远程工作区（远程放宽非法字符集合，且不检查 Windows 保留名）。 */
   isRemote: boolean;
+  /** 被校验对象是否为文件夹，用于选择准确的错误文案。 */
+  isDirectory?: boolean;
   /** 同级已存在的名称（大小写不敏感比较），用于检测重名冲突。需已排除被校验对象自身原名。 */
   siblings?: string[];
   /** 单路径段名称最大长度，默认 {@link MAX_NAME_LENGTH}。 */
@@ -47,7 +49,9 @@ export function validateFileName(raw: string, ctx: ValidateFileNameContext): str
   // 2. 非法字符
   const validPattern = ctx.isRemote ? INVALID_CHARS_REMOTE : INVALID_CHARS_LOCAL;
   if (!validPattern.test(trimmed)) {
-    return 'validation.invalidFilename';
+    return ctx.isDirectory
+      ? 'validation.invalidFolderName'
+      : 'validation.invalidFilename';
   }
 
   // 3. Windows 保留名（仅本地）