feat: 重新设计现代化图标系统

新增 Icons.tsx 统一图标组件（25 个图标）：
- AppIcon: 渐变蓝色圆角矩形 + M↓ 符号
- 工具栏: FolderOpen, Save, SplitView, EditMode, PreviewMode, Moon, Sun
- 标签栏: Close, Plus
- 侧边栏: Folder, File, ChevronRight, FolderPlus
- 搜索栏: ChevronUp, ChevronDown, X
- 拖拽: UploadCloud
- 导航: ArrowUp, ArrowDown
- 欢迎: WelcomeFile, WelcomeNew

设计风格：
- 线性图标（stroke-based），统一 1.75px 线宽
- 圆角风格，现代科技感
- 蓝色主色调渐变应用图标
- 部分图标添加微妙的填充细节（opacity 0.3-0.4）

更新组件：
- Toolbar: 使用 FolderOpen/Save/SplitView/EditMode/PreviewMode/Moon/Sun
- TabBar: 使用 Close/Plus
- Sidebar: 使用 FolderPlus/File/Folder/ChevronRight
- SearchBar: 使用 ChevronUp/ChevronDown/X
- WelcomeScreen: 使用 AppIcon/WelcomeFile/WelcomeNew
- DropOverlay: 使用 UploadCloud

src/renderer/components/DropOverlay/DropOverlay.tsx

@@ -1,7 +1,7 @@
 import React, { useState, useEffect } from 'react'
+import { UploadCloud } from '../Icons'
 
 export function DropOverlay() {
-  // L-11: 简化为单一状态
   const [dragCounter, setDragCounter] = useState(0)
 
   useEffect(() => {
@@ -41,9 +41,7 @@ export function DropOverlay() {
   return (
     <div id="drop-overlay">
       <div className="drop-content">
-        <svg width="64" height="64" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round">
-          <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z" />
-        </svg>
+        <UploadCloud size={64} />
         <p>释放文件以打开</p>
       </div>
     </div>

src/renderer/components/Icons.tsx

@@ -0,0 +1,251 @@
+import React from 'react'
+
+// 统一图标 Props
+interface IconProps {
+  size?: number
+  className?: string
+  style?: React.CSSProperties
+}
+
+const defaultProps: Partial<IconProps> = { size: 18 }
+
+// ===== 应用图标 =====
+export function AppIcon({ size = 80 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 80 80" fill="none" xmlns="http://www.w3.org/2000/svg">
+      {/* 背景圆角矩形 */}
+      <rect x="4" y="4" width="72" height="72" rx="16" fill="url(#app-bg)" stroke="url(#app-stroke)" strokeWidth="2"/>
+      {/* Markdown M↓ 符号 */}
+      <path d="M22 28v24M22 52V40l8-8 8 8v12M46 28l6 12 6-12v24" stroke="white" strokeWidth="3.5" strokeLinecap="round" strokeLinejoin="round"/>
+      {/* 底部装饰线 */}
+      <rect x="16" y="60" width="48" height="3" rx="1.5" fill="rgba(255,255,255,0.3)"/>
+      <defs>
+        <linearGradient id="app-bg" x1="4" y1="4" x2="76" y2="76" gradientUnits="userSpaceOnUse">
+          <stop stopColor="#3B82F6"/>
+          <stop offset="1" stopColor="#1D4ED8"/>
+        </linearGradient>
+        <linearGradient id="app-stroke" x1="4" y1="4" x2="76" y2="76" gradientUnits="userSpaceOnUse">
+          <stop stopColor="#60A5FA"/>
+          <stop offset="1" stopColor="#2563EB"/>
+        </linearGradient>
+      </defs>
+    </svg>
+  )
+}
+
+// ===== 工具栏图标 =====
+export function FolderOpen({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M5 19a2 2 0 0 1-2-2V7a2 2 0 0 1 2-2h4l2 2h6a2 2 0 0 1 2 2v1"/>
+      <path d="M20.5 15H5a2 2 0 0 0-2 2l1.5 7h18l2-7a2 2 0 0 0-2-2h-2.5z" fill="none"/>
+      <path d="M12 11h4" strokeDasharray="2 2"/>
+    </svg>
+  )
+}
+
+export function Save({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M19 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11l5 5v11a2 2 0 0 1-2 2z"/>
+      <polyline points="17 21 17 13 7 13 7 21"/>
+      <polyline points="7 3 7 8 15 8"/>
+    </svg>
+  )
+}
+
+export function SplitView({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <rect x="3" y="3" width="18" height="18" rx="3"/>
+      <line x1="12" y1="3" x2="12" y2="21"/>
+      <rect x="5" y="7" width="5" height="2" rx="1" fill="currentColor" opacity="0.4"/>
+      <rect x="5" y="11" width="3" height="2" rx="1" fill="currentColor" opacity="0.3"/>
+      <rect x="14" y="7" width="5" height="2" rx="1" fill="currentColor" opacity="0.4"/>
+      <rect x="14" y="11" width="3" height="2" rx="1" fill="currentColor" opacity="0.3"/>
+    </svg>
+  )
+}
+
+export function EditMode({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"/>
+      <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"/>
+      <circle cx="18" cy="6" r="1" fill="currentColor"/>
+    </svg>
+  )
+}
+
+export function PreviewMode({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M1 12s4-8 11-8 11 8 11 8-4 8-11 8-11-8-11-8z"/>
+      <circle cx="12" cy="12" r="3"/>
+      <circle cx="12" cy="12" r="1" fill="currentColor"/>
+    </svg>
+  )
+}
+
+export function Moon({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z"/>
+      <circle cx="19" cy="5" r="1" fill="currentColor" opacity="0.5"/>
+    </svg>
+  )
+}
+
+export function Sun({ size = defaultProps.size }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <circle cx="12" cy="12" r="5"/>
+      <circle cx="12" cy="12" r="2" fill="currentColor" opacity="0.3"/>
+      <line x1="12" y1="1" x2="12" y2="3"/>
+      <line x1="12" y1="21" x2="12" y2="23"/>
+      <line x1="4.22" y1="4.22" x2="5.64" y2="5.64"/>
+      <line x1="18.36" y1="18.36" x2="19.78" y2="19.78"/>
+      <line x1="1" y1="12" x2="3" y2="12"/>
+      <line x1="21" y1="12" x2="23" y2="12"/>
+      <line x1="4.22" y1="19.78" x2="5.64" y2="18.36"/>
+      <line x1="18.36" y1="5.64" x2="19.78" y2="4.22"/>
+    </svg>
+  )
+}
+
+// ===== 标签栏图标 =====
+export function Close({ size = 10 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round">
+      <line x1="18" y1="6" x2="6" y2="18"/>
+      <line x1="6" y1="6" x2="18" y2="18"/>
+    </svg>
+  )
+}
+
+export function Plus({ size = 14 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
+      <line x1="12" y1="5" x2="12" y2="19"/>
+      <line x1="5" y1="12" x2="19" y2="12"/>
+    </svg>
+  )
+}
+
+// ===== 侧边栏图标 =====
+export function Folder({ size = 14 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z"/>
+      <line x1="9" y1="13" x2="15" y2="13" opacity="0.4"/>
+    </svg>
+  )
+}
+
+export function File({ size = 14 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"/>
+      <polyline points="14 2 14 8 20 8"/>
+      <line x1="8" y1="13" x2="16" y2="13" opacity="0.4"/>
+      <line x1="8" y1="17" x2="13" y2="17" opacity="0.3"/>
+    </svg>
+  )
+}
+
+export function ChevronRight({ size = 10 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
+      <polyline points="9 18 15 12 9 6"/>
+    </svg>
+  )
+}
+
+export function FolderPlus({ size = 14 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z"/>
+      <line x1="12" y1="11" x2="12" y2="17"/>
+      <line x1="9" y1="14" x2="15" y2="14"/>
+    </svg>
+  )
+}
+
+// ===== 搜索栏图标 =====
+export function ChevronUp({ size = 12 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
+      <polyline points="18 15 12 9 6 15"/>
+    </svg>
+  )
+}
+
+export function ChevronDown({ size = 12 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
+      <polyline points="6 9 12 15 18 9"/>
+    </svg>
+  )
+}
+
+export function X({ size = 14 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round">
+      <line x1="18" y1="6" x2="6" y2="18"/>
+      <line x1="6" y1="6" x2="18" y2="18"/>
+    </svg>
+  )
+}
+
+// ===== 拖拽覆盖层图标 =====
+export function UploadCloud({ size = 64 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.25" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M4 14.899A7 7 0 1 1 15.71 8h1.79a4.5 4.5 0 0 1 2.5 8.242"/>
+      <polyline points="12 16 12 8"/>
+      <polyline points="8 12 12 8 16 12"/>
+      <line x1="12" y1="16" x2="12" y2="22"/>
+    </svg>
+  )
+}
+
+// ===== 箭头/导航图标 =====
+export function ArrowUp({ size = 12 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
+      <line x1="12" y1="19" x2="12" y2="5"/>
+      <polyline points="5 12 12 5 19 12"/>
+    </svg>
+  )
+}
+
+export function ArrowDown({ size = 12 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
+      <line x1="12" y1="5" x2="12" y2="19"/>
+      <polyline points="19 12 12 19 5 12"/>
+    </svg>
+  )
+}
+
+// ===== 欢迎屏幕图标 =====
+export function WelcomeFile({ size = 20 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z"/>
+      <line x1="12" y1="11" x2="12" y2="17"/>
+      <line x1="9" y1="14" x2="15" y2="14"/>
+    </svg>
+  )
+}
+
+export function WelcomeNew({ size = 20 }: IconProps) {
+  return (
+    <svg width={size} height={size} viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.75" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z"/>
+      <polyline points="14 2 14 8 20 8"/>
+      <line x1="12" y1="18" x2="12" y2="12"/>
+      <line x1="9" y1="15" x2="15" y2="15"/>
+    </svg>
+  )
+}

src/renderer/components/SearchBar/SearchBar.tsx

@@ -2,6 +2,7 @@ import React, { useCallback, useRef, useEffect } from 'react'
 import { useSearchStore } from '../../stores/searchStore'
 import { useTabStore } from '../../stores/tabStore'
 import { findMatches } from '../../lib/searchEngine'
+import { ChevronUp, ChevronDown, X } from '../Icons'
 
 export function SearchBar() {
   const searchInputRef = useRef<HTMLInputElement>(null)
@@ -25,7 +26,6 @@ export function SearchBar() {
 
   const getActiveTab = useTabStore(s => s.getActiveTab)
 
-  // 执行搜索
   const doSearch = useCallback((text: string) => {
     const tab = getActiveTab()
     if (!tab || !text) {
@@ -36,21 +36,18 @@ export function SearchBar() {
     setMatches(found)
   }, [getActiveTab, options, setMatches])
 
-  // 搜索文本变化
   const handleSearchChange = useCallback((e: React.ChangeEvent<HTMLInputElement>) => {
     const text = e.target.value
     setSearchText(text)
     doSearch(text)
   }, [setSearchText, doSearch])
 
-  // 替换当前
   const handleReplaceCurrent = useCallback(() => {
     const tab = getActiveTab()
     if (!tab || matches.length === 0 || currentIndex < 0) return
     const m = matches[currentIndex]
     const newContent = tab.content.substring(0, m.start) + replaceText + tab.content.substring(m.end)
     useTabStore.getState().updateTabContent(tab.id, newContent)
-    // 重新搜索
     doSearch(searchText)
   }, [getActiveTab, matches, currentIndex, replaceText, searchText, doSearch])
 
@@ -67,7 +64,6 @@ export function SearchBar() {
     doSearch(searchText)
   }, [getActiveTab, matches, replaceText, searchText, doSearch])
 
-  // 打开时聚焦
   useEffect(() => {
     if (isVisible && searchInputRef.current) {
       searchInputRef.current.focus()
@@ -123,16 +119,14 @@ export function SearchBar() {
           .*
         </button>
         <button className="search-nav-btn" onClick={findPrev} title="上一个 (Shift+Enter)">
-          <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5">
-            <polyline points="18 15 12 9 6 15" />
-          </svg>
+          <ChevronUp size={12} />
         </button>
         <button className="search-nav-btn" onClick={findNext} title="下一个 (Enter)">
-          <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5">
-            <polyline points="6 9 12 15 18 9" />
-          </svg>
+          <ChevronDown size={12} />
+        </button>
+        <button className="search-nav-btn" onClick={close} title="关闭 (Escape)">
+          <X size={14} />
         </button>
-        <button className="search-nav-btn" onClick={close} title="关闭 (Escape)">✕</button>
       </div>
 
       {showReplace && (

src/renderer/components/Sidebar/Sidebar.tsx

@@ -2,6 +2,7 @@ import React, { useEffect, useCallback, useState, useRef } from 'react'
 import { useTabStore } from '../../stores/tabStore'
 import { useSidebarStore } from '../../stores/sidebarStore'
 import { getFileName } from '../../lib/fileUtils'
+import { FolderPlus, File, Folder, ChevronRight } from '../Icons'
 import type { FileNode } from '../../types/file'
 
 export function Sidebar() {
@@ -19,22 +20,19 @@ export function Sidebar() {
   const isVisible = useSidebarStore(s => s.isVisible)
   const expandDirs = useSidebarStore(s => s.expandDirs)
 
-  // M-01: 归一化路径分隔符（Windows 混合 \\ 和 /）
+  // M-01: 归一化路径分隔符
   const norm = (p: string) => p.replace(/\\/g, '/')
   const activeFilePath = tabs.find(t => t.id === activeTabId)?.filePath ?? null
 
   // 自动展开到活动文件所在的目录
   useEffect(() => {
     if (!activeFilePath || !rootPath) return
-    // M-01: 归一化后比较
     const normActive = norm(activeFilePath)
     const normRoot = norm(rootPath)
     if (!normActive.startsWith(normRoot)) return
 
-    // 提取文件的所有父目录路径
     const dirsToExpand: string[] = []
-    let dir = activeFilePath.replace(/[/\\][^/\\]+$/, '') // 移除文件名
-    // M-02: 添加 prev 防护无限循环
+    let dir = activeFilePath.replace(/[/\\][^/\\]+$/, '')
     let prev = ''
     while (dir && dir.length >= rootPath.length && dir !== rootPath && dir !== prev) {
       prev = dir
@@ -50,7 +48,6 @@ export function Sidebar() {
   const [isResizing, setIsResizing] = useState(false)
   const sidebarRef = useRef<HTMLDivElement>(null)
 
-  // 打开文件夹
   const handleOpenFolder = useCallback(async () => {
     if (!window.electronAPI) return
     const dirPath = await window.electronAPI.openFolderDialog()
@@ -64,7 +61,6 @@ export function Sidebar() {
     }
   }, [setRootPath, setTree])
 
-  // 刷新目录树
   const refreshTree = useCallback(async () => {
     if (!rootPath || !window.electronAPI) return
     const result = await window.electronAPI.readDirTree(rootPath)
@@ -73,7 +69,6 @@ export function Sidebar() {
     }
   }, [rootPath, setTree])
 
-  // 目录变化监听
   useEffect(() => {
     if (!window.electronAPI) return
     window.electronAPI.onDirChanged(() => {
@@ -84,7 +79,6 @@ export function Sidebar() {
     }
   }, [refreshTree])
 
-  // 侧边栏宽度调节
   useEffect(() => {
     if (!isResizing) return
     const handleMouseMove = (e: MouseEvent) => {
@@ -102,7 +96,6 @@ export function Sidebar() {
     }
   }, [isResizing])
 
-  // L-12: 提取为 useCallback 避免每次渲染重建
   const handleFileClick = useCallback(async (path: string) => {
     const existing = tabs.find(t => t.filePath === path)
     if (existing) {
@@ -114,6 +107,7 @@ export function Sidebar() {
       }
     }
   }, [tabs, switchToTab, createTab])
+
   // M-01: 独立文件区（归一化路径比较）
   const independentFiles = tabs.filter(t => {
     if (!t.filePath) return false
@@ -128,9 +122,7 @@ export function Sidebar() {
       <div id="sidebar-header">
         <span id="sidebar-title">资源管理器</span>
         <button className="sidebar-header-btn" onClick={handleOpenFolder} title="打开文件夹">
-          <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-            <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z" />
-          </svg>
+          <FolderPlus size={14} />
         </button>
       </div>
 
@@ -147,10 +139,7 @@ export function Sidebar() {
                 onClick={() => switchToTab(tab.id)}
               >
                 <span className="tree-icon">
-                  <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
-                    <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
-                    <polyline points="14 2 14 8 20 8" />
-                  </svg>
+                  <File size={14} />
                 </span>
                 <span className="tree-name">{getFileName(tab.filePath!)}</span>
                 {tab.isModified && <span className="independent-modified-dot"> •</span>}
@@ -176,7 +165,6 @@ export function Sidebar() {
         )}
       </div>
 
-      {/* 调节手柄 */}
       <div
         className="sidebar-resize-handle"
         onMouseDown={() => setIsResizing(true)}
@@ -213,24 +201,17 @@ function FileTree({ nodes, depth, expandedDirs, toggleDir, activeTabId, activeFi
             {node.type === 'dir' ? (
               <>
                 <span className={`tree-arrow ${expandedDirs.has(node.path) ? 'expanded' : ''}`}>
-                  <svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5">
-                    <polyline points="9 18 15 12 9 6" />
-                  </svg>
+                  <ChevronRight size={10} />
                 </span>
                 <span className="tree-icon">
-                  <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
-                    <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z" />
-                  </svg>
+                  <Folder size={14} />
                 </span>
               </>
             ) : (
               <>
                 <span style={{ width: '16px', flexShrink: 0 }} />
                 <span className="tree-icon">
-                  <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
-                    <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
-                    <polyline points="14 2 14 8 20 8" />
-                  </svg>
+                  <File size={14} />
                 </span>
               </>
             )}

src/renderer/components/TabBar/TabBar.tsx

@@ -1,6 +1,7 @@
 import React, { useCallback, useState, useEffect, useRef } from 'react'
 import { useTabStore } from '../../stores/tabStore'
 import { getFileName } from '../../lib/fileUtils'
+import { Close, Plus } from '../Icons'
 
 interface ContextMenuState {
   visible: boolean
@@ -22,7 +23,6 @@ export function TabBar() {
   const [menu, setMenu] = useState<ContextMenuState>({ visible: false, x: 0, y: 0, tabId: '' })
   const menuRef = useRef<HTMLDivElement>(null)
 
-  // 关闭标签（带未保存确认）
   const handleClose = useCallback((e: React.MouseEvent, tabId: string) => {
     e.stopPropagation()
     const tab = tabs.find(t => t.id === tabId)
@@ -44,7 +44,6 @@ export function TabBar() {
     setMenu({ visible: true, x: Math.max(0, x), y: Math.max(0, y), tabId })
   }, [])
 
-  // 点击空白处关闭菜单
   useEffect(() => {
     if (!menu.visible) return
     const handleClick = () => setMenu(prev => ({ ...prev, visible: false }))
@@ -52,7 +51,6 @@ export function TabBar() {
     return () => document.removeEventListener('click', handleClick)
   }, [menu.visible])
 
-  // 菜单操作
   const handleMenuClose = useCallback(() => {
     const tab = tabs.find(t => t.id === menu.tabId)
     if (tab?.isModified) {
@@ -64,7 +62,6 @@ export function TabBar() {
   }, [tabs, menu.tabId, closeTab])
 
   const handleMenuCloseOthers = useCallback(() => {
-    // 检查其他标签是否有未保存
     const otherModified = tabs.filter(t => t.id !== menu.tabId && t.isModified)
     if (otherModified.length > 0) {
       const names = otherModified.map(t => t.filePath ? getFileName(t.filePath) : '未命名').join('、')
@@ -96,7 +93,6 @@ export function TabBar() {
     setMenu(prev => ({ ...prev, visible: false }))
   }, [tabs, menu.tabId, closeTabsToRight])
 
-  // 判断右侧是否还有标签
   const hasRightTabs = menu.visible && (() => {
     const index = tabs.findIndex(t => t.id === menu.tabId)
     return index < tabs.length - 1
@@ -121,10 +117,7 @@ export function TabBar() {
               className="tab-close"
               onClick={(e) => handleClose(e, tab.id)}
             >
-              <svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
-                <line x1="18" y1="6" x2="6" y2="18" />
-                <line x1="6" y1="6" x2="18" y2="18" />
-              </svg>
+              <Close size={10} />
             </button>
           </div>
         ))}
@@ -134,10 +127,7 @@ export function TabBar() {
         onClick={() => createTab(null, '')}
         title="新建标签页 (Ctrl+T)"
       >
-        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-          <line x1="12" y1="5" x2="12" y2="19" />
-          <line x1="5" y1="12" x2="19" y2="12" />
-        </svg>
+        <Plus size={14} />
       </button>
 
       {/* 右键菜单 */}
@@ -151,7 +141,6 @@ export function TabBar() {
           <div className="tab-context-item" onClick={handleMenuClose}>
             关闭
           </div>
-          {/* M-03: 单标签时隐藏"关闭其他标签" */}
           {tabs.length > 1 && (
             <div className="tab-context-item" onClick={handleMenuCloseOthers}>
               关闭其他标签

src/renderer/components/Toolbar/Toolbar.tsx

@@ -1,4 +1,5 @@
 import React from 'react'
+import { FolderOpen, Save, SplitView, EditMode, PreviewMode, Moon, Sun } from '../Icons'
 
 interface ToolbarProps {
   onOpen: () => void
@@ -14,61 +15,30 @@ export function Toolbar({ onOpen, onSave, viewMode, onViewModeChange, darkMode,
     <div id="toolbar">
       <div className="toolbar-left">
         <button className="toolbar-btn" onClick={onOpen} title="打开文件 (Ctrl+O)">
-          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-            <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z" />
-          </svg>
+          <FolderOpen size={18} />
           <span>打开</span>
         </button>
         <button className="toolbar-btn" onClick={onSave} title="保存文件 (Ctrl+S)">
-          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-            <path d="M19 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h11l5 5v11a2 2 0 0 1-2 2z" />
-            <polyline points="17 21 17 13 7 13 7 21" />
-            <polyline points="7 3 7 8 15 8" />
-          </svg>
+          <Save size={18} />
           <span>保存</span>
         </button>
         <div className="toolbar-divider" />
         <button className={`toolbar-btn ${viewMode === 'split' ? 'active' : ''}`} onClick={() => onViewModeChange('split')} title="编辑+预览 (Ctrl+1)">
-          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-            <rect x="3" y="3" width="18" height="18" rx="2" ry="2" />
-            <line x1="12" y1="3" x2="12" y2="21" />
-          </svg>
+          <SplitView size={18} />
           <span>分屏</span>
         </button>
         <button className={`toolbar-btn ${viewMode === 'editor' ? 'active' : ''}`} onClick={() => onViewModeChange('editor')} title="纯编辑 (Ctrl+2)">
-          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-            <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7" />
-            <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z" />
-          </svg>
+          <EditMode size={18} />
           <span>编辑</span>
         </button>
         <button className={`toolbar-btn ${viewMode === 'preview' ? 'active' : ''}`} onClick={() => onViewModeChange('preview')} title="纯预览 (Ctrl+3)">
-          <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-            <path d="M1 12s4-8 11-8 11 8 11 8-4 8-11 8-11-8-11-8z" />
-            <circle cx="12" cy="12" r="3" />
-          </svg>
+          <PreviewMode size={18} />
           <span>预览</span>
         </button>
       </div>
       <div className="toolbar-right">
         <button className="toolbar-btn" onClick={onToggleDark} title="切换暗色主题">
-          {darkMode ? (
-            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-              <circle cx="12" cy="12" r="5" />
-              <line x1="12" y1="1" x2="12" y2="3" />
-              <line x1="12" y1="21" x2="12" y2="23" />
-              <line x1="4.22" y1="4.22" x2="5.64" y2="5.64" />
-              <line x1="18.36" y1="18.36" x2="19.78" y2="19.78" />
-              <line x1="1" y1="12" x2="3" y2="12" />
-              <line x1="21" y1="12" x2="23" y2="12" />
-              <line x1="4.22" y1="19.78" x2="5.64" y2="18.36" />
-              <line x1="18.36" y1="5.64" x2="19.78" y2="4.22" />
-            </svg>
-          ) : (
-            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-              <path d="M21 12.79A9 9 0 1 1 11.21 3 7 7 0 0 0 21 12.79z" />
-            </svg>
-          )}
+          {darkMode ? <Sun size={18} /> : <Moon size={18} />}
         </button>
       </div>
     </div>

src/renderer/components/WelcomeScreen/WelcomeScreen.tsx

@@ -1,4 +1,5 @@
 import React from 'react'
+import { AppIcon, WelcomeFile, WelcomeNew } from '../Icons'
 
 interface WelcomeScreenProps {
   onOpen: () => void
@@ -10,26 +11,17 @@ export function WelcomeScreen({ onOpen, onNew }: WelcomeScreenProps) {
     <div id="welcome-screen">
       <div className="welcome-content">
         <div className="welcome-icon">
-          <svg width="80" height="80" viewBox="0 0 100 100" fill="none" xmlns="http://www.w3.org/2000/svg">
-            <rect x="10" y="5" width="80" height="90" rx="8" fill="#f0f6ff" stroke="#1a73e8" strokeWidth="2" />
-            <text x="50" y="45" textAnchor="middle" fill="#1a73e8" fontFamily="system-ui" fontWeight="bold" fontSize="32">M↓</text>
-            <text x="50" y="70" textAnchor="middle" fill="#5f6368" fontFamily="system-ui" fontSize="12">MarkLite</text>
-          </svg>
+          <AppIcon size={80} />
         </div>
         <h1>欢迎使用 MarkLite</h1>
-        <p>一款轻量级的 Markdown 阅读器</p>
+        <p>一款轻量级的 Markdown 编辑器</p>
         <div className="welcome-actions">
           <button className="welcome-btn primary" onClick={onOpen}>
-            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-              <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z" />
-            </svg>
+            <WelcomeFile size={20} />
             打开文件
           </button>
           <button className="welcome-btn secondary" onClick={onNew}>
-            <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-              <line x1="12" y1="5" x2="12" y2="19" />
-              <line x1="5" y1="12" x2="19" y2="12" />
-            </svg>
+            <WelcomeNew size={20} />
             新建文件
           </button>
         </div>