feat: uploadHEADmaster

Signed-off-by: zwlucas <lucas.fariamo08@gmail.com>

33 files changed, 3108 insertions, 0 deletions

diff --git a/src/App.tsx b/src/App.tsx
new file mode 100644
index 0000000..d04b328
--- /dev/null
+++ b/src/App.tsx
@@ -0,0 +1,46 @@
+import TitleBar from '@/components/TitleBar/TitleBar'
+import ActivityBar from '@/components/ActivityBar/ActivityBar'
+import SidePanel from '@/components/SidePanel/SidePanel'
+import TabsBar from '@/components/TabsBar/TabsBar'
+import Breadcrumbs from '@/components/Breadcrumbs/Breadcrumbs'
+import WelcomeScreen from '@/components/Welcome/WelcomeScreen'
+import YaceEditor from '@/components/Editor/YaceEditor'
+import StatusBar from '@/components/StatusBar/StatusBar'
+import CommandPalette from '@/components/CommandPalette/CommandPalette'
+import ContextMenu from '@/components/ContextMenu/ContextMenu'
+import Toasts from '@/components/Toasts/Toasts'
+import { useKeyboard } from '@/hooks/useKeyboard'
+import { useLayoutStore } from '@/stores/useLayoutStore'
+import { useTabsStore } from '@/stores/useTabsStore'
+
+export default function App() {
+  useKeyboard()
+  const sidePanelVisible = useLayoutStore((s) => s.sidePanelVisible)
+  const activeView = useLayoutStore((s) => s.activeView)
+  const activeTabId = useTabsStore((s) => s.activeTabId)
+
+  return (
+    <div className="h-screen w-screen flex flex-col overflow-hidden bg-editor-bg" onContextMenu={(e) => e.preventDefault()}>
+      <TitleBar />
+      <CommandPalette />
+      <ContextMenu />
+      <Toasts />
+      <div className="flex flex-1 overflow-hidden">
+        <ActivityBar />
+        {sidePanelVisible && activeView && <SidePanel />}
+        <div className="flex flex-col flex-1 overflow-hidden min-w-0">
+          {activeTabId ? (
+            <>
+              <TabsBar />
+              <Breadcrumbs />
+              <YaceEditor />
+            </>
+          ) : (
+            <WelcomeScreen />
+          )}
+        </div>
+      </div>
+      <StatusBar />
+    </div>
+  )
+}
diff --git a/src/components/ActivityBar/ActivityBar.tsx b/src/components/ActivityBar/ActivityBar.tsx
new file mode 100644
index 0000000..7f96b5c
--- /dev/null
+++ b/src/components/ActivityBar/ActivityBar.tsx
@@ -0,0 +1,147 @@
+import { useLayoutStore, type ActivityView } from '@/stores/useLayoutStore'
+import { useThemeStore } from '@/stores/useThemeStore'
+
+interface ActivityItem {
+  view: ActivityView
+  label: string
+}
+
+function ExplorerIcon() {
+  return (
+    <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>
+  )
+}
+
+function SearchIcon() {
+  return (
+    <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+      <circle cx="11" cy="11" r="8" />
+      <line x1="21" y1="21" x2="16.65" y2="16.65" />
+    </svg>
+  )
+}
+
+function ExtensionsIcon() {
+  return (
+    <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+      <path d="M4 11a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h5a2 2 0 0 1 2 2v5a2 2 0 0 1-2 2z" />
+      <path d="M15 11a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h5a2 2 0 0 1 2 2v5a2 2 0 0 1-2 2z" />
+      <path d="M15 22a2 2 0 0 1-2-2v-5a2 2 0 0 1 2-2h5a2 2 0 0 1 2 2v5a2 2 0 0 1-2 2z" />
+      <path d="M4 22a2 2 0 0 1-2-2v-5a2 2 0 0 1 2-2h5a2 2 0 0 1 2 2v5a2 2 0 0 1-2 2z" />
+    </svg>
+  )
+}
+
+function SettingsIcon() {
+  return (
+    <svg width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+      <circle cx="12" cy="12" r="3" />
+      <path d="M19.4 15a1.65 1.65 0 0 0 .33 1.82l.06.06a2 2 0 0 1 0 2.83 2 2 0 0 1-2.83 0l-.06-.06a1.65 1.65 0 0 0-1.82-.33 1.65 1.65 0 0 0-1 1.51V21a2 2 0 0 1-2 2 2 2 0 0 1-2-2v-.09A1.65 1.65 0 0 0 9 19.4a1.65 1.65 0 0 0-1.82.33l-.06.06a2 2 0 0 1-2.83 0 2 2 0 0 1 0-2.83l.06-.06A1.65 1.65 0 0 0 4.68 15a1.65 1.65 0 0 0-1.51-1H3a2 2 0 0 1-2-2 2 2 0 0 1 2-2h.09A1.65 1.65 0 0 0 4.6 9a1.65 1.65 0 0 0-.33-1.82l-.06-.06a2 2 0 0 1 0-2.83 2 2 0 0 1 2.83 0l.06.06A1.65 1.65 0 0 0 9 4.68a1.65 1.65 0 0 0 1-1.51V3a2 2 0 0 1 2-2 2 2 0 0 1 2 2v.09a1.65 1.65 0 0 0 1 1.51 1.65 1.65 0 0 0 1.82-.33l.06-.06a2 2 0 0 1 2.83 0 2 2 0 0 1 0 2.83l-.06.06A1.65 1.65 0 0 0 19.4 9a1.65 1.65 0 0 0 1.51 1H21a2 2 0 0 1 2 2 2 2 0 0 1-2 2h-.09a1.65 1.65 0 0 0-1.51 1z" />
+    </svg>
+  )
+}
+
+function MoonIcon() {
+  return (
+    <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" 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>
+  )
+}
+
+function SunIcon() {
+  return (
+    <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" 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>
+  )
+}
+
+const activities: ActivityItem[] = [
+  { view: 'explorer', label: 'Explorer' },
+  { view: 'search', label: 'Search' },
+  { view: 'extensions', label: 'Extensions' },
+]
+
+const bottomActivities: ActivityItem[] = [
+  { view: 'settings', label: 'Settings' },
+]
+
+const iconMap: Record<string, typeof ExplorerIcon> = {
+  explorer: ExplorerIcon,
+  search: SearchIcon,
+  extensions: ExtensionsIcon,
+  settings: SettingsIcon,
+}
+
+function ActivityButton({ item, isActive, setActiveView }: { item: ActivityItem; isActive: boolean; setActiveView: (view: ActivityView | null) => void }) {
+  const IconComponent = iconMap[item.view] || ExplorerIcon
+
+  return (
+    <button
+      role="tab"
+      aria-label={item.label}
+      aria-current={isActive ? 'true' : undefined}
+      className="relative flex items-center justify-center w-10 h-10 rounded-lg transition-all duration-fast hover:bg-panel-hover"
+      style={{ color: isActive ? 'var(--color-text-primary)' : 'var(--color-text-muted)' }}
+      onClick={() => setActiveView(item.view)}
+      title={item.label}
+    >
+      {isActive && (
+        <span className="absolute left-0 w-[3px] h-6 rounded-r-sm bg-accent" style={{ left: '-4px' }} />
+      )}
+      <span className={isActive ? '' : 'opacity-50 group-hover:opacity-80 transition-opacity duration-fast'}>
+        <IconComponent />
+      </span>
+    </button>
+  )
+}
+
+export default function ActivityBar() {
+  const activeView = useLayoutStore((s) => s.activeView)
+  const setActiveView = useLayoutStore((s) => s.setActiveView)
+  const theme = useThemeStore((s) => s.theme)
+  const toggleTheme = useThemeStore((s) => s.toggleTheme)
+
+  return (
+    <div className="flex flex-col items-center pt-2 gap-1 w-12 shrink-0 bg-activity-bg select-none group" role="tablist" aria-label="Main navigation">
+      {activities.map((item) => (
+        <ActivityButton
+          key={item.view}
+          item={item}
+          isActive={activeView === item.view}
+          setActiveView={setActiveView}
+        />
+      ))}
+
+      <div className="flex-1" />
+
+      {bottomActivities.map((item) => (
+        <ActivityButton
+          key={item.view}
+          item={item}
+          isActive={activeView === item.view}
+          setActiveView={setActiveView}
+        />
+      ))}
+
+      <button
+        className="flex items-center justify-center w-10 h-10 rounded-lg transition-all duration-fast hover:bg-panel-hover text-text-muted hover:text-text-primary mb-2"
+        onClick={toggleTheme}
+        title={`Switch to ${theme === 'dark' ? 'light' : 'dark'} mode`}
+      >
+        {theme === 'dark' ? <SunIcon /> : <MoonIcon />}
+      </button>
+    </div>
+  )
+}
diff --git a/src/components/Breadcrumbs/Breadcrumbs.tsx b/src/components/Breadcrumbs/Breadcrumbs.tsx
new file mode 100644
index 0000000..dbdeef0
--- /dev/null
+++ b/src/components/Breadcrumbs/Breadcrumbs.tsx
@@ -0,0 +1,55 @@
+import { useTabsStore } from '@/stores/useTabsStore'
+import { useFilesStore } from '@/stores/useFilesStore'
+
+export default function Breadcrumbs() {
+  const tabs = useTabsStore((s) => s.tabs)
+  const activeTabId = useTabsStore((s) => s.activeTabId)
+  const rootPath = useFilesStore((s) => s.rootPath)
+
+  if (!activeTabId || !rootPath) return null
+
+  const activeTab = tabs.find((t) => t.id === activeTabId)
+  if (!activeTab) return null
+
+  const fullPath = activeTab.path
+  let relativePath = fullPath
+
+  if (fullPath.startsWith(rootPath)) {
+    relativePath = fullPath.slice(rootPath.length).replace(/^[\\/]/, '')
+  }
+
+  const segments = relativePath.split(/[\\/]/)
+  const lastIdx = segments.length - 1
+
+  return (
+    <div className="flex items-center h-[26px] px-4 shrink-0 bg-editor-bg select-none gap-0 text-ui-xs overflow-hidden">
+      {segments.map((segment, i) => {
+        const isLast = i === lastIdx
+
+        if (isLast) {
+          return (
+            <span
+              key={i}
+              className="truncate text-text-primary font-medium"
+            >
+              {segment}
+            </span>
+          )
+        }
+
+        return (
+          <span key={i} className="flex items-center gap-0 min-w-0 shrink-0">
+            <button
+              className="truncate text-text-muted hover:text-text-secondary px-1 py-0.5 rounded transition-all duration-fast hover:bg-panel-hover cursor-pointer"
+            >
+              {segment}
+            </button>
+            <svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round" className="shrink-0 text-text-muted opacity-30 mx-[2px]">
+              <polyline points="9 18 15 12 9 6" />
+            </svg>
+          </span>
+        )
+      })}
+    </div>
+  )
+}
diff --git a/src/components/CommandPalette/CommandPalette.tsx b/src/components/CommandPalette/CommandPalette.tsx
new file mode 100644
index 0000000..eba6221
--- /dev/null
+++ b/src/components/CommandPalette/CommandPalette.tsx
@@ -0,0 +1,201 @@
+import { useEffect, useRef, useMemo } from 'react'
+import { useCommandStore } from '@/stores/useCommandStore'
+
+function SearchIcon() {
+  return (
+    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+      <circle cx="11" cy="11" r="8" />
+      <line x1="21" y1="21" x2="16.65" y2="16.65" />
+    </svg>
+  )
+}
+
+function Kbd({ keys }: { keys: string }) {
+  return (
+    <span className="flex items-center gap-0.5 text-ui-xs">
+      {keys.split('+').map((k) => (
+        <kbd
+          key={k}
+                  className="px-1 py-[1px] rounded text-[10px] leading-none font-mono"
+                  style={{
+                    backgroundColor: 'var(--color-panel-hover)',
+                    color: 'var(--color-text-muted)',
+                    border: '1px solid var(--color-panel-border)',
+                    minWidth: '16px',
+                    textAlign: 'center',
+                  }}
+        >
+          {k === 'Ctrl' ? '⌃' : k === 'Shift' ? '⇧' : k === 'Cmd' ? '⌘' : k}
+        </kbd>
+      ))}
+    </span>
+  )
+}
+
+function CommandGroup({ category, children }: { category: string; children: React.ReactNode }) {
+  return (
+    <div>
+      <div className="px-4 py-1.5 text-ui-xs font-medium tracking-wider uppercase text-text-muted">{category}</div>
+      {children}
+    </div>
+  )
+}
+
+export default function CommandPalette() {
+  const isOpen = useCommandStore((s) => s.isOpen)
+  const query = useCommandStore((s) => s.query)
+  const selectedIndex = useCommandStore((s) => s.selectedIndex)
+  const commands = useCommandStore((s) => s.commands)
+  const setQuery = useCommandStore((s) => s.setQuery)
+  const setSelectedIndex = useCommandStore((s) => s.setSelectedIndex)
+  const executeSelected = useCommandStore((s) => s.executeSelected)
+  const close = useCommandStore((s) => s.close)
+
+  const inputRef = useRef<HTMLInputElement>(null)
+
+  const filtered = useMemo(
+    () => commands.filter(
+      (c) =>
+        c.label.toLowerCase().includes(query.toLowerCase()) ||
+        c.category.toLowerCase().includes(query.toLowerCase())
+    ),
+    [commands, query]
+  )
+
+  const grouped = useMemo(() => {
+    const map = new Map<string, typeof filtered>()
+    filtered.forEach((c) => {
+      const group = map.get(c.category) ?? []
+      group.push(c)
+      map.set(c.category, group)
+    })
+    return Array.from(map.entries())
+  }, [filtered])
+
+  useEffect(() => {
+    if (isOpen) {
+      inputRef.current?.focus()
+    }
+  }, [isOpen])
+
+  useEffect(() => {
+    if (!isOpen) return
+
+    function handleKeyDown(e: KeyboardEvent) {
+      if (e.key === 'Escape') {
+        e.preventDefault()
+        close()
+        return
+      }
+
+      if (e.key === 'Enter') {
+        e.preventDefault()
+        executeSelected()
+        return
+      }
+
+      if (e.key === 'ArrowDown') {
+        e.preventDefault()
+        setSelectedIndex(Math.min(selectedIndex + 1, filtered.length - 1))
+        return
+      }
+
+      if (e.key === 'ArrowUp') {
+        e.preventDefault()
+        setSelectedIndex(Math.max(selectedIndex - 1, 0))
+        return
+      }
+    }
+
+    window.addEventListener('keydown', handleKeyDown)
+    return () => window.removeEventListener('keydown', handleKeyDown)
+  }, [isOpen, filtered.length, selectedIndex, setSelectedIndex, executeSelected, close])
+
+  if (!isOpen) return null
+
+  return (
+    <div
+      className="fixed inset-0 z-50 flex justify-center"
+      style={{ paddingTop: '12vh' }}
+      onClick={close}
+      role="dialog"
+      aria-label="Command palette"
+    >
+      <div className="absolute inset-0 backdrop-glass" />
+
+      <div
+        className="relative w-full max-w-[520px] rounded-xl shadow-glass overflow-hidden"
+        style={{
+          backgroundColor: 'var(--color-panel-bg)',
+          border: '1px solid var(--color-panel-border)',
+          maxHeight: '60vh',
+          display: 'flex',
+          flexDirection: 'column',
+        }}
+        onClick={(e) => e.stopPropagation()}
+      >
+        <div className="flex items-center gap-3 px-4 h-11 shrink-0" style={{ borderBottom: '1px solid var(--color-panel-border)' }}>
+          <span className="text-text-muted shrink-0"><SearchIcon /></span>
+          <input
+            ref={inputRef}
+            type="text"
+            value={query}
+            onChange={(e) => setQuery(e.target.value)}
+            placeholder="Type a command..."
+            className="flex-1 bg-transparent text-ui-base text-text-primary outline-none placeholder:text-text-muted"
+          />
+        </div>
+
+        <div className="flex-1 overflow-y-auto py-2" role="listbox">
+          {filtered.length === 0 && (
+            <div className="px-4 py-6 text-ui-sm text-text-muted text-center">
+              No results found
+            </div>
+          )}
+
+          {grouped.map(([category, items]) => (
+            <CommandGroup key={category} category={category}>
+              {items.map((cmd) => {
+                const idx = filtered.indexOf(cmd)
+                const isSelected = idx === selectedIndex
+
+                return (
+                <button
+                  key={cmd.id}
+                  role="option"
+                  aria-selected={isSelected ? 'true' : 'false'}
+                  className="w-full flex items-center justify-between px-4 py-1.5 text-left transition-colors duration-fast"
+                    style={{
+                      backgroundColor: isSelected ? 'var(--color-panel-hover)' : 'transparent',
+                      color: isSelected ? 'var(--color-text-primary)' : 'var(--color-text-secondary)',
+                    }}
+                    onMouseEnter={() => setSelectedIndex(idx)}
+                    onClick={() => {
+                      cmd.action()
+                      close()
+                    }}
+                  >
+                    <span className="text-ui-sm truncate">{cmd.label}</span>
+                    {cmd.shortcut && <Kbd keys={cmd.shortcut} />}
+                  </button>
+                )
+              })}
+            </CommandGroup>
+          ))}
+
+          <div className="px-4 pt-2 pb-1 flex items-center gap-3 text-ui-xs text-text-muted border-t border-panel-border mt-2">
+            <span className="flex items-center gap-1">
+              <Kbd keys="↑↓" /> navigate
+            </span>
+            <span className="flex items-center gap-1">
+              <Kbd keys="↵" /> select
+            </span>
+            <span className="flex items-center gap-1">
+              <Kbd keys="Esc" /> close
+            </span>
+          </div>
+        </div>
+      </div>
+    </div>
+  )
+}
diff --git a/src/components/ContextMenu/ContextMenu.tsx b/src/components/ContextMenu/ContextMenu.tsx
new file mode 100644
index 0000000..2c67116
--- /dev/null
+++ b/src/components/ContextMenu/ContextMenu.tsx
@@ -0,0 +1,184 @@
+import { useEffect, useRef, useState } from 'react'
+import { useContextMenuStore, type ContextMenuIcon } from '@/stores/useContextMenuStore'
+
+function MenuIcon({ icon }: { icon: ContextMenuIcon }) {
+  const c = 'currentColor'
+  switch (icon) {
+    case 'undo':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <polyline points="1 4 1 10 7 10" /><path d="M3.51 15a9 9 0 1 0 2.13-9.36L1 10" />
+        </svg>
+      )
+    case 'redo':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <polyline points="23 4 23 10 17 10" /><path d="M20.49 15a9 9 0 1 1-2.13-9.36L23 10" />
+        </svg>
+      )
+    case 'cut':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <circle cx="6" cy="6" r="3" /><circle cx="6" cy="18" r="3" /><line x1="8.12" y1="8.12" x2="15.88" y2="15.88" /><line x1="15.88" y1="8.12" x2="8.12" y2="15.88" />
+        </svg>
+      )
+    case 'copy':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <rect x="9" y="9" width="13" height="13" rx="2" ry="2" /><path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1" />
+        </svg>
+      )
+    case 'paste':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <path d="M16 4h2a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V6a2 2 0 0 1 2-2h2" /><rect x="8" y="2" width="8" height="4" rx="1" ry="1" />
+        </svg>
+      )
+    case 'selectAll':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <rect x="3" y="3" width="18" height="18" rx="2" ry="2" /><line x1="9" y1="3" x2="9" y2="21" /><line x1="15" y1="3" x2="15" y2="21" /><line x1="3" y1="9" x2="21" y2="9" /><line x1="3" y1="15" x2="21" y2="15" />
+        </svg>
+      )
+    case 'close':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <line x1="18" y1="6" x2="6" y2="18" /><line x1="6" y1="6" x2="18" y2="18" />
+        </svg>
+      )
+    case 'rename':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} 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>
+      )
+    case 'trash':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <polyline points="3 6 5 6 21 6" /><path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2" />
+        </svg>
+      )
+    case 'folder':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} 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>
+      )
+    case 'file':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" 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" />
+        </svg>
+      )
+    case 'link':
+      return (
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke={c} strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+          <path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71" /><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71" />
+        </svg>
+      )
+  }
+}
+
+export default function ContextMenu() {
+  const isOpen = useContextMenuStore((s) => s.isOpen)
+  const x = useContextMenuStore((s) => s.x)
+  const y = useContextMenuStore((s) => s.y)
+  const items = useContextMenuStore((s) => s.items)
+  const close = useContextMenuStore((s) => s.close)
+
+  const menuRef = useRef<HTMLDivElement>(null)
+  const [adjustedPos, setAdjustedPos] = useState({ x, y })
+  const [selectedIndex, setSelectedIndex] = useState(0)
+
+  const visibleItems = items.filter((i) => !i.separator)
+  const totalItems = visibleItems.length
+
+  useEffect(() => {
+    if (!isOpen || !menuRef.current) return
+    const rect = menuRef.current.getBoundingClientRect()
+    const vw = window.innerWidth
+    const vh = window.innerHeight
+    setAdjustedPos({
+      x: x + rect.width > vw ? vw - rect.width - 12 : x,
+      y: y + rect.height > vh ? vh - rect.height - 12 : y,
+    })
+    setSelectedIndex(0)
+  }, [isOpen, x, y])
+
+  useEffect(() => {
+    if (!isOpen) return
+    function handleKeyDown(e: KeyboardEvent) {
+      if (e.key === 'Escape') { e.preventDefault(); close(); return }
+      if (e.key === 'ArrowDown') { e.preventDefault(); setSelectedIndex((i) => Math.min(i + 1, totalItems - 1)); return }
+      if (e.key === 'ArrowUp') { e.preventDefault(); setSelectedIndex((i) => Math.max(i - 1, 0)); return }
+      if (e.key === 'Enter') {
+        e.preventDefault()
+        const item = visibleItems[selectedIndex]
+        if (item && !item.disabled) { item.action(); close() }
+      }
+    }
+    window.addEventListener('keydown', handleKeyDown)
+    return () => window.removeEventListener('keydown', handleKeyDown)
+  }, [isOpen, selectedIndex, totalItems, visibleItems, close])
+
+  useEffect(() => {
+    if (!isOpen || !menuRef.current) return
+    function handleClickOutside(e: MouseEvent) {
+      if (menuRef.current && !menuRef.current.contains(e.target as Node)) {
+        close()
+      }
+    }
+    requestAnimationFrame(() => window.addEventListener('mousedown', handleClickOutside))
+    return () => window.removeEventListener('mousedown', handleClickOutside)
+  }, [isOpen, close])
+
+  if (!isOpen) return null
+
+  return (
+    <div
+      ref={menuRef}
+      className="fixed z-50 min-w-[180px] py-1 rounded-xl shadow-glass overflow-hidden context-menu"
+      style={{
+        left: adjustedPos.x,
+        top: adjustedPos.y,
+        backgroundColor: 'var(--color-panel-bg)',
+        border: '1px solid var(--color-panel-border)',
+      }}
+    >
+      {items.map((item) => {
+        if (item.separator) {
+          return (
+            <div key={item.id} className="my-1 mx-2" style={{ height: '1px', backgroundColor: 'var(--color-panel-border)' }} />
+          )
+        }
+        const idx = visibleItems.indexOf(item)
+        const isSelected = idx === selectedIndex
+        return (
+          <button
+            key={item.id}
+            role="menuitem"
+            disabled={item.disabled}
+            className="w-full flex items-center gap-2.5 px-3 py-1.5 text-ui-sm text-left transition-colors duration-fast disabled:opacity-30 disabled:cursor-default"
+            style={{
+              backgroundColor: isSelected ? 'var(--color-panel-hover)' : 'transparent',
+              color: item.disabled ? 'var(--color-text-muted)' : 'var(--color-text-secondary)',
+            }}
+            onMouseEnter={() => setSelectedIndex(idx)}
+            onClick={() => { if (!item.disabled) { item.action(); close() } }}
+          >
+            {item.icon && (
+              <span className="w-[14px] shrink-0 text-text-muted">
+                <MenuIcon icon={item.icon} />
+              </span>
+            )}
+            {!item.icon && <span className="w-[14px] shrink-0" />}
+            <span className="flex-1 truncate">{item.label}</span>
+            {item.shortcut && (
+              <span className="text-ui-xs text-text-muted ml-4">{item.shortcut}</span>
+            )}
+          </button>
+        )
+      })}
+    </div>
+  )
+}
diff --git a/src/components/Editor/YaceEditor.tsx b/src/components/Editor/YaceEditor.tsx
new file mode 100644
index 0000000..f3152e1
--- /dev/null
+++ b/src/components/Editor/YaceEditor.tsx
@@ -0,0 +1,291 @@
+import { useCallback, useEffect, useRef, useMemo } from 'react'
+import {
+  EditorView, keymap,
+  highlightActiveLine, highlightActiveLineGutter,
+  lineNumbers,
+} from '@codemirror/view'
+import { EditorState, type Extension } from '@codemirror/state'
+import { defaultKeymap, indentWithTab, undo, redo } from '@codemirror/commands'
+import { syntaxHighlighting, indentUnit, HighlightStyle } from '@codemirror/language'
+import { tags } from '@lezer/highlight'
+import { json } from '@codemirror/lang-json'
+import { javascript } from '@codemirror/lang-javascript'
+import { markdown } from '@codemirror/lang-markdown'
+import { html } from '@codemirror/lang-html'
+import { css } from '@codemirror/lang-css'
+import { rust } from '@codemirror/lang-rust'
+import { python } from '@codemirror/lang-python'
+import { useTabsStore } from '@/stores/useTabsStore'
+import { useContextMenuStore } from '@/stores/useContextMenuStore'
+import { useSettingsStore } from '@/stores/useSettingsStore'
+
+function buildLanguageExtensions(language: string) {
+  switch (language) {
+    case 'typescript':
+      return javascript({ typescript: true })
+    case 'javascript':
+      return javascript()
+    case 'json':
+      return json()
+    case 'markdown':
+      return markdown()
+    case 'html':
+      return html()
+    case 'css':
+      return css()
+    case 'rust':
+      return rust()
+    case 'python':
+      return python()
+    default:
+      return []
+  }
+}
+
+const tokyoNightSyntax = HighlightStyle.define([
+  { tag: tags.keyword, color: '#7aa2f7' },
+  { tag: [tags.controlKeyword, tags.operatorKeyword], color: '#7aa2f7' },
+  { tag: tags.modifier, color: '#7aa2f7' },
+  { tag: tags.definitionKeyword, color: '#7aa2f7' },
+  { tag: tags.moduleKeyword, color: '#7aa2f7' },
+  { tag: tags.self, color: '#ff5370' },
+  { tag: tags.atom, color: '#ff9e64' },
+  { tag: tags.bool, color: '#ff9e64' },
+  { tag: tags.null, color: '#ff9e64' },
+  { tag: tags.number, color: '#ff9e64' },
+  { tag: tags.string, color: '#9ece6a' },
+  { tag: tags.character, color: '#9ece6a' },
+  { tag: tags.regexp, color: '#89ddff' },
+  { tag: tags.escape, color: '#bb9af7' },
+  { tag: tags.typeName, color: '#e0af68' },
+  { tag: tags.className, color: '#e0af68' },
+  { tag: tags.namespace, color: '#89ddff' },
+  { tag: tags.macroName, color: '#ff5370' },
+  { tag: tags.propertyName, color: '#73daca' },
+  { tag: tags.attributeName, color: '#73daca' },
+  { tag: tags.variableName, color: '#c0caf5' },
+  { tag: tags.labelName, color: '#c0caf5' },
+  { tag: tags.operator, color: '#89ddff' },
+  { tag: tags.bracket, color: '#a9b1d6' },
+  { tag: tags.angleBracket, color: '#89ddff' },
+  { tag: tags.paren, color: '#a9b1d6' },
+  { tag: tags.brace, color: '#a9b1d6' },
+  { tag: tags.squareBracket, color: '#a9b1d6' },
+  { tag: tags.separator, color: '#a9b1d6' },
+  { tag: tags.punctuation, color: '#a9b1d6' },
+  { tag: tags.comment, color: '#565f89', fontStyle: 'italic' },
+  { tag: tags.lineComment, color: '#565f89', fontStyle: 'italic' },
+  { tag: tags.blockComment, color: '#565f89', fontStyle: 'italic' },
+  { tag: tags.docComment, color: '#565f89', fontStyle: 'italic' },
+  { tag: tags.docString, color: '#565f89' },
+  { tag: tags.meta, color: '#565f89' },
+  { tag: tags.content, color: '#c0caf5' },
+  { tag: tags.heading, color: '#7aa2f7', fontWeight: '600' },
+  { tag: tags.strong, color: '#c0caf5', fontWeight: '700' },
+  { tag: tags.emphasis, color: '#c0caf5', fontStyle: 'italic' },
+  { tag: tags.strikethrough, color: '#565f89', textDecoration: 'line-through' },
+  { tag: tags.link, color: '#73daca', textDecoration: 'underline' },
+  { tag: tags.url, color: '#73daca', textDecoration: 'underline' },
+  { tag: tags.list, color: '#7dcfff' },
+  { tag: tags.quote, color: '#9ece6a' },
+  { tag: tags.inserted, color: '#9ece6a' },
+  { tag: tags.deleted, color: '#ff5370' },
+  { tag: tags.changed, color: '#e0af68' },
+  { tag: tags.invalid, color: '#ff5370' },
+  { tag: tags.definition(tags.variableName), color: '#c0caf5' },
+  { tag: tags.definition(tags.propertyName), color: '#73daca' },
+  { tag: tags.function(tags.variableName), color: '#7dcfff' },
+  { tag: tags.definition(tags.function(tags.variableName)), color: '#7dcfff' },
+  { tag: tags.local(tags.variableName), color: '#c0caf5' },
+  { tag: tags.special(tags.variableName), color: '#ff5370' },
+  { tag: tags.special(tags.string), color: '#bb9af7' },
+])
+
+function buildEditorTheme(settings: {
+  fontSize: number
+  fontFamily: string
+  ruler: boolean
+  rulerColumn: number
+}) {
+  const rulerCSS = settings.ruler
+    ? `linear-gradient(90deg, transparent calc(${settings.rulerColumn}ch + 0.5px), var(--color-ruler) calc(${settings.rulerColumn}ch + 0.5px), var(--color-ruler) calc(${settings.rulerColumn + 0.5}ch + 0.5px), transparent calc(${settings.rulerColumn + 0.5}ch + 0.5px))`
+    : 'none'
+
+  return EditorView.theme({
+    '&': {
+      fontSize: `${settings.fontSize}px`,
+      fontFamily: `'${settings.fontFamily}', 'Cascadia Code', 'Fira Code', Consolas, monospace`,
+      height: '100%',
+      backgroundColor: 'var(--color-editor-bg)',
+    },
+    '.cm-scroller': {
+      fontFamily: `'${settings.fontFamily}', 'Cascadia Code', 'Fira Code', Consolas, monospace`,
+    },
+    '.cm-content': {
+      padding: '16px 0',
+      caretColor: 'var(--color-accent)',
+      backgroundImage: rulerCSS,
+      backgroundPosition: '0 0',
+      backgroundRepeat: 'no-repeat',
+    },
+    '.cm-line': {
+      padding: '0 20px',
+    },
+    '.cm-gutters': {
+      backgroundColor: 'var(--color-editor-surface)',
+      borderRight: '1px solid var(--color-panel-border)',
+      color: 'var(--color-text-muted)',
+    },
+    '.cm-lineNumbers .cm-gutterElement': {
+      padding: '0 12px 0 16px',
+      fontSize: '12px',
+      fontFamily: `'${settings.fontFamily}', 'Cascadia Code', 'Fira Code', Consolas, monospace`,
+      lineHeight: '1.6',
+    },
+    '.cm-activeLineGutter': {
+      backgroundColor: 'var(--color-editor-line)',
+      color: 'var(--color-text-primary)',
+      fontWeight: '600',
+    },
+    '.cm-activeLine': {
+      backgroundColor: 'rgba(12,12,14,0.5)',
+    },
+    '.cm-cursor': {
+      borderLeftWidth: '2px',
+      borderLeftColor: 'var(--color-accent)',
+    },
+    '&.cm-focused .cm-cursor': {
+      borderLeftColor: 'var(--color-accent)',
+    },
+    '.cm-selectionBackground': {
+      backgroundColor: 'rgba(240,160,48,0.2) !important',
+    },
+    '&.cm-focused > .cm-scroller > .cm-selectionLayer .cm-selectionBackground': {
+      backgroundColor: 'rgba(240,160,48,0.25) !important',
+    },
+    '.cm-selectionMatch': {
+      backgroundColor: 'rgba(240,160,48,0.1) !important',
+    },
+  })
+}
+
+export default function YaceEditor() {
+  const editorRef = useRef<HTMLDivElement>(null)
+  const viewRef = useRef<EditorView | null>(null)
+  const containerRef = useRef<HTMLDivElement>(null)
+  const updateTimeoutRef = useRef<ReturnType<typeof setTimeout> | undefined>(undefined)
+
+  const activeTab = useTabsStore((s) =>
+    s.activeTabId ? s.tabs.find((t) => t.id === s.activeTabId) ?? null : null
+  )
+  const updateContent = useTabsStore((s) => s.updateContent)
+  const setCursorPosition = useTabsStore((s) => s.setCursorPosition)
+  const openContextMenu = useContextMenuStore((s) => s.open)
+
+  const fontSize = useSettingsStore((s) => s.fontSize)
+  const tabSize = useSettingsStore((s) => s.tabSize)
+  const fontFamily = useSettingsStore((s) => s.fontFamily)
+  const wordWrap = useSettingsStore((s) => s.wordWrap)
+  const lineNumbersEnabled = useSettingsStore((s) => s.lineNumbers)
+  const ruler = useSettingsStore((s) => s.ruler)
+  const rulerColumn = useSettingsStore((s) => s.rulerColumn)
+
+  const settings = { fontSize, tabSize, fontFamily, wordWrap, lineNumbers: lineNumbersEnabled, ruler, rulerColumn }
+
+  const editorItems = useMemo(() => [
+    { id: 'undo', label: 'Undo', shortcut: 'Ctrl+Z', icon: 'undo' as const, action: () => viewRef.current && undo(viewRef.current) },
+    { id: 'redo', label: 'Redo', shortcut: 'Ctrl+Shift+Z', icon: 'redo' as const, action: () => viewRef.current && redo(viewRef.current) },
+    { id: 'sep1', label: '', separator: true, action: () => {} },
+    { id: 'cut', label: 'Cut', shortcut: 'Ctrl+X', icon: 'cut' as const, action: () => { document.execCommand('cut') } },
+    { id: 'copy', label: 'Copy', shortcut: 'Ctrl+C', icon: 'copy' as const, action: () => { document.execCommand('copy') } },
+    { id: 'paste', label: 'Paste', shortcut: 'Ctrl+V', icon: 'paste' as const, action: () => { navigator.clipboard.readText().then((t) => viewRef.current?.dispatch({ changes: { from: viewRef.current.state.selection.main.head, insert: t } })) } },
+    { id: 'sep2', label: '', separator: true, action: () => {} },
+    { id: 'selectAll', label: 'Select All', shortcut: 'Ctrl+A', icon: 'selectAll' as const, action: () => { viewRef.current?.dispatch({ selection: { anchor: 0, head: viewRef.current.state.doc.length } }) } },
+  ], [])
+
+  const handleContextMenu = useCallback((e: MouseEvent) => {
+    e.preventDefault()
+    openContextMenu(e.clientX, e.clientY, editorItems)
+  }, [openContextMenu, editorItems])
+
+  const handleChange = useCallback(
+    (content: string) => {
+      if (updateTimeoutRef.current) clearTimeout(updateTimeoutRef.current)
+      updateTimeoutRef.current = setTimeout(() => {
+        const id = useTabsStore.getState().activeTabId
+        if (id) updateContent(id, content)
+      }, 300)
+    },
+    [updateContent]
+  )
+
+  useEffect(() => {
+    if (!editorRef.current) return
+
+    if (viewRef.current) viewRef.current.destroy()
+
+    const languageExtensions = activeTab
+      ? buildLanguageExtensions(activeTab.language)
+      : []
+
+    const updateListener = EditorView.updateListener.of((update) => {
+      if (update.docChanged) {
+        handleChange(update.state.doc.toString())
+      }
+      if (update.selectionSet) {
+        const pos = update.state.selection.main.head
+        const line = update.state.doc.lineAt(pos)
+        setCursorPosition(line.number, pos - line.from + 1)
+      }
+    })
+
+    const extensions: Extension[] = [
+      ...(lineNumbersEnabled ? [lineNumbers(), highlightActiveLineGutter()] : [highlightActiveLineGutter()]),
+      highlightActiveLine(),
+      updateListener,
+      keymap.of([...defaultKeymap, indentWithTab]),
+      syntaxHighlighting(tokyoNightSyntax),
+      buildEditorTheme(settings),
+      EditorState.tabSize.of(tabSize),
+      indentUnit.of(' '.repeat(tabSize)),
+      languageExtensions,
+    ]
+
+    if (wordWrap) {
+      extensions.push(EditorView.lineWrapping)
+    }
+
+    const state = EditorState.create({
+      doc: activeTab?.content ?? '',
+      extensions: extensions.flat(),
+    })
+
+    viewRef.current = new EditorView({
+      state,
+      parent: editorRef.current,
+    })
+
+    return () => {
+      if (updateTimeoutRef.current) clearTimeout(updateTimeoutRef.current)
+      viewRef.current?.destroy()
+      viewRef.current = null
+    }
+  }, [activeTab?.id, activeTab?.language, fontSize, tabSize, fontFamily, wordWrap, lineNumbersEnabled, ruler, rulerColumn])
+
+  useEffect(() => {
+    const el = containerRef.current
+    if (!el) return
+    el.addEventListener('contextmenu', handleContextMenu)
+    return () => el.removeEventListener('contextmenu', handleContextMenu)
+  }, [handleContextMenu])
+
+  if (!activeTab) {
+    return null
+  }
+
+  return (
+    <div ref={containerRef} className="flex-1 overflow-hidden bg-editor-bg">
+      <div ref={editorRef} className="h-full" />
+    </div>
+  )
+}
diff --git a/src/components/Settings/SettingsPanel.tsx b/src/components/Settings/SettingsPanel.tsx
new file mode 100644
index 0000000..e4a4b6b
--- /dev/null
+++ b/src/components/Settings/SettingsPanel.tsx
@@ -0,0 +1,106 @@
+import { useSettingsStore } from '@/stores/useSettingsStore'
+import { useThemeStore } from '@/stores/useThemeStore'
+import Toggle from '@/components/UI/Toggle'
+import Slider from '@/components/UI/Slider'
+import Input from '@/components/UI/Input'
+
+function Section({ label, children }: { label: string; children: React.ReactNode }) {
+  return (
+    <div className="mb-6">
+      <div className="px-3 py-1.5 text-ui-xs font-medium tracking-[0.08em] uppercase text-text-muted">
+        {label}
+      </div>
+      <div className="flex flex-col">{children}</div>
+    </div>
+  )
+}
+
+function Row({ label, children }: { label: string; children: React.ReactNode }) {
+  return (
+    <div className="flex items-center justify-between px-3 py-2 min-h-[34px] gap-4">
+      <span className="text-ui-sm text-text-secondary shrink-0">{label}</span>
+      <div className="w-[140px] shrink-0">{children}</div>
+    </div>
+  )
+}
+
+export default function SettingsPanel() {
+  const settings = useSettingsStore()
+  const toggleTheme = useThemeStore((s) => s.toggleTheme)
+  const theme = useThemeStore((s) => s.theme)
+
+  return (
+    <div className="flex-1 overflow-y-auto overflow-x-hidden">
+      <Section label="Interface">
+        <Row label="Theme">
+          <button
+            onClick={toggleTheme}
+            className="flex items-center justify-between w-full h-7 px-2.5 rounded-md text-ui-sm text-text-primary bg-editor-surface border transition-all duration-150 hover:brightness-110"
+            style={{ borderColor: 'var(--color-panel-border)' }}
+          >
+            <span>{theme === 'dark' ? 'Dark' : 'Light'}</span>
+            <span className="text-text-muted text-ui-xs">
+              {theme === 'dark' ? '🌙' : '☀️'}
+            </span>
+          </button>
+        </Row>
+        <Row label="Font Size">
+          <div className="flex items-center gap-2">
+            <Slider
+              value={settings.fontSize}
+              min={10}
+              max={24}
+              step={1}
+              onChange={(v) => settings.set('fontSize', v)}
+            />
+            <span className="text-ui-xs text-text-muted w-5 text-right tabular-nums">{settings.fontSize}</span>
+          </div>
+        </Row>
+        <Row label="Tab Size">
+          <div className="flex items-center gap-2">
+            <Slider
+              value={settings.tabSize}
+              min={1}
+              max={8}
+              step={1}
+              onChange={(v) => settings.set('tabSize', v)}
+            />
+            <span className="text-ui-xs text-text-muted w-5 text-right tabular-nums">{settings.tabSize}</span>
+          </div>
+        </Row>
+      </Section>
+
+      <Section label="Editor">
+        <Row label="Word Wrap">
+          <Toggle
+            checked={settings.wordWrap}
+            onChange={(v) => settings.set('wordWrap', v)}
+          />
+        </Row>
+        <Row label="Line Numbers">
+          <Toggle
+            checked={settings.lineNumbers}
+            onChange={(v) => settings.set('lineNumbers', v)}
+          />
+        </Row>
+        <Row label="Ruler">
+          <Toggle
+            checked={settings.ruler}
+            onChange={(v) => settings.set('ruler', v)}
+          />
+        </Row>
+        <Row label="Ruler Column">
+          <Input
+            type="number"
+            value={settings.rulerColumn}
+            min={40}
+            max={200}
+            onChange={(v) => settings.set('rulerColumn', parseInt(v) || 80)}
+          />
+        </Row>
+      </Section>
+
+      <div className="h-2" />
+    </div>
+  )
+}
diff --git a/src/components/SidePanel/SidePanel.tsx b/src/components/SidePanel/SidePanel.tsx
new file mode 100644
index 0000000..14668fb
--- /dev/null
+++ b/src/components/SidePanel/SidePanel.tsx
@@ -0,0 +1,187 @@
+import { useRef, useCallback, useEffect } from 'react'
+import FileTree from '@/components/Sidebar/FileTree'
+import SettingsPanel from '@/components/Settings/SettingsPanel'
+import { useFilesStore } from '@/stores/useFilesStore'
+import { useTabsStore } from '@/stores/useTabsStore'
+import { useLayoutStore } from '@/stores/useLayoutStore'
+
+function NewFileIcon() {
+  return (
+    <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" 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>
+  )
+}
+
+function NewFolderIcon() {
+  return (
+    <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" />
+      <line x1="12" y1="11" x2="12" y2="17" />
+      <line x1="9" y1="14" x2="15" y2="14" />
+    </svg>
+  )
+}
+
+function OpenFolderIcon() {
+  return (
+    <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>
+  )
+}
+
+export default function SidePanel() {
+  const fileTree = useFilesStore((s) => s.fileTree)
+  const rootPath = useFilesStore((s) => s.rootPath)
+  const loading = useFilesStore((s) => s.loading)
+  const openFolder = useFilesStore((s) => s.openFolder)
+  const createFolder = useFilesStore((s) => s.createFolder)
+  const createUntitledFile = useTabsStore((s) => s.createUntitledFile)
+
+  const sidePanelWidth = useLayoutStore((s) => s.sidePanelWidth)
+  const setSidePanelWidth = useLayoutStore((s) => s.setSidePanelWidth)
+  const activeView = useLayoutStore((s) => s.activeView)
+
+  const dragRef = useRef(false)
+  const panelRef = useRef<HTMLDivElement>(null)
+
+  const handleMouseDown = useCallback(() => {
+    dragRef.current = true
+    document.body.style.cursor = 'col-resize'
+    document.body.style.userSelect = 'none'
+  }, [])
+
+  const handleMouseMove = useCallback((e: MouseEvent) => {
+    if (!dragRef.current || !panelRef.current) return
+    const rect = panelRef.current.getBoundingClientRect()
+    const newWidth = e.clientX - rect.left
+    setSidePanelWidth(newWidth)
+  }, [setSidePanelWidth])
+
+  const handleMouseUp = useCallback(() => {
+    dragRef.current = false
+    document.body.style.cursor = ''
+    document.body.style.userSelect = ''
+  }, [])
+
+  useEffect(() => {
+    window.addEventListener('mousemove', handleMouseMove)
+    window.addEventListener('mouseup', handleMouseUp)
+    return () => {
+      window.removeEventListener('mousemove', handleMouseMove)
+      window.removeEventListener('mouseup', handleMouseUp)
+    }
+  }, [handleMouseMove, handleMouseUp])
+
+  return (
+    <div
+      ref={panelRef}
+      className="relative flex flex-col h-full panel-mica select-none shrink-0 overflow-hidden"
+      style={{ width: `${sidePanelWidth}px` }}
+      role="complementary"
+      aria-label="Side panel"
+    >
+      <div className="group flex items-center justify-between px-3 shrink-0 h-tabs border-b border-panel-border">
+        <span className="uppercase tracking-widest text-[11px] font-medium text-zinc-500">
+          {activeView === 'search' ? 'SEARCH' : activeView === 'extensions' ? 'EXTENSIONS' : activeView === 'settings' ? 'SETTINGS' : 'EXPLORER'}
+        </span>
+        <div className="flex items-center gap-0.5 opacity-0 group-hover:opacity-100 transition-opacity duration-fast">
+            {activeView === 'explorer' && (
+              <>
+                <button
+                  onClick={() => createUntitledFile()}
+                  className="p-1 rounded text-zinc-500 hover:text-zinc-300 hover:bg-panel-hover transition-all duration-fast"
+                  title="New File"
+                >
+                  <NewFileIcon />
+                </button>
+                {rootPath && (
+                  <button
+                    onClick={() => createFolder()}
+                    className="p-1 rounded text-zinc-500 hover:text-zinc-300 hover:bg-panel-hover transition-all duration-fast"
+                    title="New Folder"
+                  >
+                    <NewFolderIcon />
+                  </button>
+                )}
+                <button
+                  onClick={openFolder}
+                  className="p-1 rounded text-zinc-500 hover:text-zinc-300 hover:bg-panel-hover transition-all duration-fast"
+                  title={rootPath ? 'Open another folder' : 'Open Folder'}
+                >
+                  <OpenFolderIcon />
+                </button>
+            </>
+          )}
+        </div>
+      </div>
+
+      <div className="flex-1 overflow-y-auto overflow-x-hidden">
+        {activeView === 'explorer' && (
+          <>
+            {!rootPath && !loading && (
+              <div className="flex flex-col items-center gap-3 px-4 py-8 text-center">
+                <svg width="32" height="32" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round" className="text-text-muted">
+                  <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>
+                <p className="text-ui-sm text-text-secondary">No folder open</p>
+                <button
+                  onClick={openFolder}
+                  className="px-3 py-1.5 text-ui-xs font-medium rounded transition-all duration-150 hover:brightness-110 bg-accent text-editor-bg"
+                >
+                  Open Folder
+                </button>
+              </div>
+            )}
+
+            {loading && (
+              <div className="flex items-center justify-center gap-2 py-8">
+                <div className="w-3 h-3 rounded-full animate-pulse bg-accent" />
+                <span className="text-ui-sm text-text-secondary">Loading...</span>
+              </div>
+            )}
+
+            {rootPath && !loading && (
+              <>
+                <div className="px-3 py-1.5 text-ui-xs font-medium truncate text-text-muted border-b border-panel-border" title={rootPath}>
+                  {rootPath.split(/[\\/]/).pop()}
+                </div>
+                {fileTree.length > 0 ? (
+                  <FileTree entries={fileTree} />
+                ) : (
+                  <div className="py-8 text-ui-sm text-text-secondary text-center">Empty directory</div>
+                )}
+              </>
+            )}
+          </>
+        )}
+
+        {activeView === 'search' && (
+          <div className="flex items-center justify-center py-8 text-ui-sm text-text-muted">
+            Search coming soon
+          </div>
+        )}
+
+        {activeView === 'extensions' && (
+          <div className="flex items-center justify-center py-8 text-ui-sm text-text-muted">
+            Extensions coming soon
+          </div>
+        )}
+
+        {activeView === 'settings' && (
+          <SettingsPanel />
+        )}
+      </div>
+
+      <div
+        className="absolute right-0 top-0 bottom-0 w-[4px] cursor-col-resize hover:bg-accent/30 transition-colors duration-fast"
+        style={{ right: '-2px' }}
+        onMouseDown={handleMouseDown}
+      />
+    </div>
+  )
+}
diff --git a/src/components/Sidebar/FileTree.tsx b/src/components/Sidebar/FileTree.tsx
new file mode 100644
index 0000000..03e05e7
--- /dev/null
+++ b/src/components/Sidebar/FileTree.tsx
@@ -0,0 +1,227 @@
+import { useState, useCallback } from 'react'
+import type { FileEntry } from '@/types'
+import { useTabsStore } from '@/stores/useTabsStore'
+import { useContextMenuStore } from '@/stores/useContextMenuStore'
+
+const extColors: Record<string, string> = {
+  ts: '#3178c6',
+  tsx: '#3178c6',
+  js: '#f7df1e',
+  jsx: '#f7df1e',
+  rs: '#dea584',
+  json: '#5eb7e0',
+  md: '#e8e8ed',
+  html: '#e34c4c',
+  css: '#42a5f5',
+  py: '#3572a5',
+}
+
+const ROW_HEIGHT = 32
+const INDENT = 16
+const GUIDE_COLOR = 'var(--color-panel-border)'
+const GUIDE_HOVER_COLOR = 'var(--color-text-muted)'
+
+function ChevronIcon({ expanded }: { expanded: boolean }) {
+  return (
+    <svg
+      width="16" height="16" viewBox="0 0 24 24"
+      fill="none" stroke="currentColor"
+      strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"
+      className="transition-transform duration-150 shrink-0 text-text-muted"
+      style={{ transform: expanded ? 'rotate(90deg)' : 'rotate(0deg)' }}
+    >
+      <polyline points="9 18 15 12 9 6" />
+    </svg>
+  )
+}
+
+function FileTypeIcon({ name, isDir, expanded }: { name: string; isDir: boolean; expanded: boolean }) {
+  if (isDir) {
+    return (
+      <svg
+        width="16" height="16" viewBox="0 0 24 24"
+        fill={expanded ? 'currentColor' : '#5c5e64'}
+        stroke="currentColor"
+        strokeWidth="1.5"
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        className={`shrink-0 transition-colors duration-150 ${expanded ? 'text-accent' : 'text-text-muted'}`}
+      >
+        {expanded ? (
+          <path d="M5 19a2 2 0 0 1-2-2V7a2 2 0 0 1 2-2h4l2 2h6a2 2 0 0 1 2 2v1M5 19l3-10h15l-3 10z" />
+        ) : (
+          <path d="M22 19a2 2 0 0 1-2 2H4a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h5l2 3h9a2 2 0 0 1 2 2z" />
+        )}
+      </svg>
+    )
+  }
+
+  const ext = name.split('.').pop()?.toLowerCase() ?? ''
+  const color = extColors[ext] ?? '#5c5e64'
+
+  return (
+    <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke={color} strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round" className="shrink-0">
+      <path d="M14 2H6a2 2 0 0 0-2 2v16a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V8z" />
+      <polyline points="14,2 14,8 20,8" />
+    </svg>
+  )
+}
+
+interface GuideLinesProps {
+  depth: number
+  branchDepths: number[]
+  isLast: boolean
+  parentHovered: boolean
+}
+
+function GuideLines({ depth, branchDepths, isLast, parentHovered }: GuideLinesProps) {
+  const color = parentHovered ? GUIDE_HOVER_COLOR : GUIDE_COLOR
+  const mid = ROW_HEIGHT / 2
+  const leftBase = 12
+
+  return (
+    <div className="absolute inset-0 pointer-events-none">
+      {branchDepths.map((bd) => {
+        const l = leftBase + bd * INDENT
+        return (
+          <div
+            key={bd}
+            className="absolute top-0 bottom-0"
+            style={{ left: `${l}px`, width: '1px', backgroundColor: color }}
+          />
+        )
+      })}
+      <div
+        className="absolute"
+        style={{
+          left: `${leftBase + depth * INDENT}px`,
+          width: '1px',
+          top: 0,
+          bottom: isLast ? `calc(100% - ${mid}px)` : 0,
+          backgroundColor: color,
+        }}
+      />
+      <div
+        className="absolute"
+        style={{
+          left: `${leftBase + depth * INDENT}px`,
+          width: '7px',
+          height: '1px',
+          top: `${mid}px`,
+          backgroundColor: color,
+        }}
+      />
+    </div>
+  )
+}
+
+interface FileTreeItemProps {
+  entry: FileEntry
+  depth: number
+  isLast: boolean
+  branchDepths: number[]
+}
+
+function FileTreeItem({ entry, depth, isLast, branchDepths }: FileTreeItemProps) {
+  const [expanded, setExpanded] = useState(depth < 1)
+  const [parentHovered, setParentHovered] = useState(false)
+  const openFile = useTabsStore((s) => s.openFile)
+  const activeTabId = useTabsStore((s) => s.activeTabId)
+  const openContextMenu = useContextMenuStore((s) => s.open)
+
+  const handleContextMenu = useCallback((e: React.MouseEvent) => {
+    e.preventDefault()
+    openContextMenu(e.clientX, e.clientY, [
+      { id: 'open', label: entry.is_dir ? 'Expand' : 'Open', icon: entry.is_dir ? 'folder' : 'file', action: () => entry.is_dir ? setExpanded(!expanded) : openFile(entry.path) },
+      { id: 'sep1', label: '', separator: true, action: () => {} },
+      { id: 'copyPath', label: 'Copy Path', icon: 'link', action: () => navigator.clipboard.writeText(entry.path) },
+    ])
+  }, [entry, expanded, openFile, openContextMenu])
+
+  if (entry.is_dir) {
+    return (
+      <div>
+        <button
+          className="relative w-full flex items-center text-ui-sm transition-colors duration-fast hover:bg-panel-hover focus-visible:outline-none"
+          style={{ height: `${ROW_HEIGHT}px` }}
+          tabIndex={0}
+          aria-expanded={expanded ? 'true' : 'false'}
+          aria-label={`${entry.name} (folder)`}
+          onMouseEnter={() => setParentHovered(true)}
+          onMouseLeave={() => setParentHovered(false)}
+          onClick={() => setExpanded(!expanded)}
+          onContextMenu={handleContextMenu}
+        >
+          <GuideLines depth={depth} branchDepths={branchDepths} isLast={isLast} parentHovered={parentHovered} />
+          <div className="flex items-center gap-1 relative pl-2" style={{ paddingLeft: `${12 + depth * INDENT + 18}px` }}>
+            <ChevronIcon expanded={expanded} />
+            <FileTypeIcon name={entry.name} isDir expanded={expanded} />
+            <span className="truncate text-text-primary">{entry.name}</span>
+          </div>
+        </button>
+        <div
+          className="overflow-hidden transition-all duration-normal"
+          style={{ maxHeight: expanded ? '9999px' : '0px', opacity: expanded ? 1 : 0 }}
+        >
+          {entry.children && (
+            <FileTree
+              entries={entry.children}
+              depth={depth + 1}
+              parentBranchDepths={isLast ? branchDepths : [...branchDepths, depth]}
+            />
+          )}
+        </div>
+      </div>
+    )
+  }
+
+  const isActive = entry.path === activeTabId
+
+  return (
+    <button
+      className={`relative w-full flex items-center text-ui-sm transition-colors duration-fast hover:bg-panel-hover focus-visible:outline-none ${isActive ? 'bg-panel-active' : ''}`}
+      style={{ height: `${ROW_HEIGHT}px` }}
+      tabIndex={0}
+      aria-selected={isActive ? 'true' : 'false'}
+      aria-label={entry.name}
+      onClick={() => openFile(entry.path)}
+      onContextMenu={handleContextMenu}
+    >
+      <GuideLines depth={depth} branchDepths={branchDepths} isLast={isLast} parentHovered={false} />
+      <div
+        className="flex items-center gap-1.5 relative pl-2"
+        style={{ paddingLeft: `${12 + depth * INDENT + 24}px` }}
+      >
+        <FileTypeIcon name={entry.name} isDir={false} expanded={false} />
+        <span
+          className="truncate"
+          style={{ color: isActive ? 'var(--color-text-primary)' : 'var(--color-text-secondary)' }}
+        >
+          {entry.name}
+        </span>
+      </div>
+    </button>
+  )
+}
+
+interface FileTreeProps {
+  entries: FileEntry[]
+  depth?: number
+  parentBranchDepths?: number[]
+}
+
+export default function FileTree({ entries, depth = 0, parentBranchDepths = [] }: FileTreeProps) {
+  return (
+    <div>
+      {entries.map((entry, idx) => (
+        <FileTreeItem
+          key={entry.path}
+          entry={entry}
+          depth={depth}
+          isLast={idx === entries.length - 1}
+          branchDepths={parentBranchDepths}
+        />
+      ))}
+    </div>
+  )
+}
diff --git a/src/components/StatusBar/StatusBar.tsx b/src/components/StatusBar/StatusBar.tsx
new file mode 100644
index 0000000..49f9346
--- /dev/null
+++ b/src/components/StatusBar/StatusBar.tsx
@@ -0,0 +1,163 @@
+import { useEffect, useRef } from 'react'
+import { useTabsStore } from '@/stores/useTabsStore'
+import { useSettingsStore } from '@/stores/useSettingsStore'
+
+function BranchIcon() {
+  return (
+    <svg width="11" height="11" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" className="shrink-0 opacity-60">
+      <line x1="6" y1="3" x2="6" y2="15" />
+      <circle cx="18" cy="6" r="3" />
+      <circle cx="6" cy="18" r="3" />
+      <path d="M18 9a9 9 0 0 1-9 9" />
+    </svg>
+  )
+}
+
+function ErrorIcon() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round" className="shrink-0">
+      <circle cx="12" cy="12" r="10" />
+      <line x1="12" y1="8" x2="12" y2="12" />
+      <line x1="12" y1="16" x2="12.01" y2="16" />
+    </svg>
+  )
+}
+
+function EncodingIcon() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" className="shrink-0 opacity-60">
+      <polyline points="16 18 22 12 16 6" />
+      <polyline points="8 6 2 12 8 18" />
+    </svg>
+  )
+}
+
+function Spinner() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round" className="shrink-0 animate-spin">
+      <path d="M21 12a9 9 0 1 1-6.219-8.56" />
+    </svg>
+  )
+}
+
+function Separator() {
+  return (
+    <div className="w-px h-3 mx-2 shrink-0" style={{ backgroundColor: 'var(--color-panel-border)' }} />
+  )
+}
+
+function StatusItem({
+  children,
+  title,
+  onClick,
+}: {
+  children: React.ReactNode
+  title?: string
+  onClick?: () => void
+}) {
+  return (
+    <button
+      className={`flex items-center gap-1 px-1.5 h-full text-[11px] font-medium transition-colors duration-fast ${onClick ? 'cursor-pointer' : 'cursor-default'} hover:text-text-primary`}
+      style={{ color: 'var(--color-text-muted)' }}
+      title={title}
+      onClick={onClick}
+    >
+      {children}
+    </button>
+  )
+}
+
+export default function StatusBar() {
+  const activeTab = useTabsStore((s) =>
+    s.activeTabId ? s.tabs.find((t) => t.id === s.activeTabId) ?? null : null
+  )
+  const cursorLine = useTabsStore((s) => s.cursorLine)
+  const cursorCol = useTabsStore((s) => s.cursorCol)
+  const savingId = useTabsStore((s) => s.savingId)
+  const statusMessage = useTabsStore((s) => s.statusMessage)
+  const clearStatusMessage = useTabsStore((s) => s.clearStatusMessage)
+  const tabSize = useSettingsStore((s) => s.tabSize)
+
+  const isSaving = savingId === activeTab?.id
+  const statusTimer = useRef<ReturnType<typeof setTimeout> | undefined>(undefined)
+
+  useEffect(() => {
+    if (statusMessage) {
+      if (statusTimer.current) clearTimeout(statusTimer.current)
+      statusTimer.current = setTimeout(clearStatusMessage, 2000)
+    }
+    return () => { if (statusTimer.current) clearTimeout(statusTimer.current) }
+  }, [statusMessage, clearStatusMessage])
+
+  return (
+    <div className="flex items-center h-status shrink-0 select-none bg-activity-bg text-[11px] text-text-muted font-medium" role="status" aria-label="Application status">
+      <div className="flex items-center h-full">
+        <StatusItem title="Git branch: main">
+          <BranchIcon />
+          <span>main</span>
+        </StatusItem>
+
+        <Separator />
+
+        <StatusItem title="0 errors, 0 warnings">
+          <ErrorIcon />
+          <span className="font-mono tabular-nums text-semantic-error">0</span>
+          <span className="font-mono tabular-nums text-semantic-warning">0</span>
+        </StatusItem>
+      </div>
+
+      <div className="flex-1" />
+
+      <div className="flex items-center h-full">
+        {isSaving && (
+          <StatusItem title="Saving...">
+            <Spinner />
+            <span className="text-accent">Saving</span>
+          </StatusItem>
+        )}
+
+        {statusMessage && !isSaving && (
+          <StatusItem title={statusMessage}>
+            <span className={statusMessage === 'Saved' ? 'text-semantic-success' : 'text-semantic-error'}>
+              {statusMessage === 'Saved' ? '✓' : '✗'}
+            </span>
+            <span className={statusMessage === 'Saved' ? 'text-semantic-success' : 'text-semantic-error'}>
+              {statusMessage}
+            </span>
+          </StatusItem>
+        )}
+
+        {activeTab && (
+          <StatusItem title={`Language: ${activeTab.language}`}>
+            <span className="text-text-secondary">
+              {activeTab.language.charAt(0).toUpperCase() + activeTab.language.slice(1)}
+            </span>
+          </StatusItem>
+        )}
+
+        <Separator />
+
+        <StatusItem title={`Tab Size: ${tabSize}`}>
+          <span>Spaces: {tabSize}</span>
+        </StatusItem>
+
+        <Separator />
+
+        <StatusItem title="Encoding: UTF-8">
+          <EncodingIcon />
+          <span>UTF-8</span>
+        </StatusItem>
+
+        <Separator />
+
+        {activeTab && (
+          <StatusItem title={`Line ${cursorLine}, Column ${cursorCol}`}>
+            <span className="font-mono tabular-nums text-text-secondary">
+              Ln {cursorLine}, Col {cursorCol}
+            </span>
+          </StatusItem>
+        )}
+      </div>
+    </div>
+  )
+}
diff --git a/src/components/TabsBar/TabsBar.tsx b/src/components/TabsBar/TabsBar.tsx
new file mode 100644
index 0000000..86c77ea
--- /dev/null
+++ b/src/components/TabsBar/TabsBar.tsx
@@ -0,0 +1,136 @@
+import { useRef, useEffect, useCallback, useState } from 'react'
+import { useTabsStore } from '@/stores/useTabsStore'
+import { useContextMenuStore } from '@/stores/useContextMenuStore'
+
+function CloseIcon() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round">
+      <line x1="18" y1="6" x2="6" y2="18" />
+      <line x1="6" y1="6" x2="18" y2="18" />
+    </svg>
+  )
+}
+
+export default function TabsBar() {
+  const tabs = useTabsStore((s) => s.tabs)
+  const activeTabId = useTabsStore((s) => s.activeTabId)
+  const setActiveTab = useTabsStore((s) => s.setActiveTab)
+  const closeTab = useTabsStore((s) => s.closeTab)
+  const openContextMenu = useContextMenuStore((s) => s.open)
+
+  const scrollRef = useRef<HTMLDivElement>(null)
+  const activeTabRef = useRef<HTMLDivElement>(null)
+  const [showLeftFade, setShowLeftFade] = useState(false)
+  const [showRightFade, setShowRightFade] = useState(true)
+
+  const handleTabContextMenu = useCallback((e: React.MouseEvent, tabId: string) => {
+    e.preventDefault()
+    const numTabs = tabs.length
+    openContextMenu(e.clientX, e.clientY, [
+      { id: 'close', label: 'Close', shortcut: 'Ctrl+W', icon: 'close', action: () => closeTab(tabId) },
+      { id: 'closeOthers', label: 'Close Others', action: () => { tabs.forEach((t) => { if (t.id !== tabId) closeTab(t.id) }) }, disabled: numTabs < 2 },
+      { id: 'closeAll', label: 'Close All', action: () => { tabs.forEach((t) => closeTab(t.id)) }, disabled: numTabs < 1 },
+      { id: 'sep1', label: '', separator: true, action: () => {} },
+      { id: 'copyPath', label: 'Copy Path', icon: 'link', action: () => { const tab = tabs.find((t) => t.id === tabId); if (tab) navigator.clipboard.writeText(tab.path) } },
+    ])
+  }, [tabs, closeTab, openContextMenu])
+
+  const updateFades = useCallback(() => {
+    const el = scrollRef.current
+    if (!el) return
+    setShowLeftFade(el.scrollLeft > 4)
+    setShowRightFade(el.scrollLeft < el.scrollWidth - el.clientWidth - 4)
+  }, [])
+
+  useEffect(() => {
+    const el = scrollRef.current
+    if (!el) return
+    el.addEventListener('scroll', updateFades, { passive: true })
+    updateFades()
+    return () => el.removeEventListener('scroll', updateFades)
+  }, [updateFades, tabs.length])
+
+  useEffect(() => {
+    const el = scrollRef.current
+    const tabEl = activeTabRef.current
+    if (!el || !tabEl) return
+
+    const containerRect = el.getBoundingClientRect()
+    const tabRect = tabEl.getBoundingClientRect()
+    const isVisible =
+      tabRect.left >= containerRect.left && tabRect.right <= containerRect.right
+
+    if (!isVisible) {
+      const offset = tabRect.left - containerRect.left
+      const centerOffset = offset - containerRect.width / 2 + tabRect.width / 2
+      el.scrollBy({ left: centerOffset, behavior: 'smooth' })
+    }
+  }, [activeTabId])
+
+  return (
+    <div className="relative shrink-0 h-tabs">
+      {showLeftFade && (
+        <div className="absolute left-0 top-0 bottom-0 w-6 z-10 pointer-events-none bg-gradient-to-r from-panel-bg to-transparent" />
+      )}
+      {showRightFade && (
+        <div className="absolute right-0 top-0 bottom-0 w-6 z-10 pointer-events-none bg-gradient-to-l from-panel-bg to-transparent" />
+      )}
+
+      <div
+        ref={scrollRef}
+        className="flex overflow-x-auto overflow-y-hidden h-full scroll-smooth"
+        role="tablist"
+        aria-label="Open files"
+      >
+        {tabs.length === 0 && (
+          <div className="flex items-center px-3 text-ui-sm text-text-muted shrink-0">
+            No files open
+          </div>
+        )}
+
+        {tabs.map((tab) => {
+          const isActive = tab.id === activeTabId
+
+          return (
+            <div
+              key={tab.id}
+              ref={isActive ? activeTabRef : undefined}
+              role="tab"
+              aria-selected={isActive ? 'true' : 'false'}
+              aria-label={`${tab.name}${tab.modified ? ' (modified)' : ''}`}
+              className={`group relative flex items-center gap-1.5 px-4 py-2 text-ui-sm cursor-pointer shrink-0 transition-colors duration-100 select-none border-0 ${
+                isActive
+                  ? 'bg-editor-bg text-text-primary'
+                  : 'bg-panel-bg text-text-muted hover:bg-panel-hover hover:text-text-secondary'
+              }`}
+              onClick={() => setActiveTab(tab.id)}
+              onContextMenu={(e) => handleTabContextMenu(e, tab.id)}
+            >
+              {isActive && (
+                <span className="absolute top-0 left-0 right-0 h-[2px] bg-accent rounded-b-sm" />
+              )}
+
+              <span className="truncate max-w-32">{tab.name}</span>
+
+              {tab.modified && (
+                <span className="w-[6px] h-[6px] rounded-full shrink-0 bg-text-muted group-hover:hidden" />
+              )}
+
+              <button
+                className={`flex items-center justify-center w-[18px] h-[18px] rounded-sm transition-all duration-100 -mr-1 shrink-0 hover:bg-panel-border text-text-muted hover:text-text-primary ${
+                  tab.modified ? 'hidden group-hover:flex' : 'opacity-0 group-hover:opacity-100'
+                }`}
+                onClick={(e) => {
+                  e.stopPropagation()
+                  closeTab(tab.id)
+                }}
+              >
+                <CloseIcon />
+              </button>
+            </div>
+          )
+        })}
+      </div>
+    </div>
+  )
+}
diff --git a/src/components/TitleBar/TitleBar.tsx b/src/components/TitleBar/TitleBar.tsx
new file mode 100644
index 0000000..6a491df
--- /dev/null
+++ b/src/components/TitleBar/TitleBar.tsx
@@ -0,0 +1,94 @@
+import { useState, useEffect } from 'react'
+import { appWindow } from '@tauri-apps/api/window'
+
+function MinimizeIcon() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 12 12" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round">
+      <line x1="2" y1="10" x2="10" y2="10" />
+    </svg>
+  )
+}
+
+function MaximizeIcon() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 12 12" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round">
+      <rect x="1.5" y="1.5" width="9" height="9" rx="1" />
+    </svg>
+  )
+}
+
+function RestoreIcon() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 12 12" fill="none" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" strokeLinejoin="round">
+      <rect x="3" y="0.5" width="8" height="8" rx="1" fill="var(--color-editor-bg)" />
+      <rect x="0.5" y="3" width="8" height="8" rx="1" />
+    </svg>
+  )
+}
+
+function CloseIcon() {
+  return (
+    <svg width="10" height="10" viewBox="0 0 12 12" fill="none" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round">
+      <line x1="2" y1="2" x2="10" y2="10" />
+      <line x1="10" y1="2" x2="2" y2="10" />
+    </svg>
+  )
+}
+
+export default function TitleBar() {
+  const [isMaximized, setIsMaximized] = useState(false)
+
+  useEffect(() => {
+    appWindow.isMaximized().then(setIsMaximized)
+
+    let unlisten: (() => void) | undefined
+    appWindow.onResized(() => {
+      appWindow.isMaximized().then(setIsMaximized)
+    }).then((fn) => { unlisten = fn })
+
+    return () => { unlisten?.() }
+  }, [])
+
+  return (
+    <div
+      className="flex items-center h-titlebar bg-editor-bg shrink-0 select-none"
+      data-tauri-drag-region
+    >
+      <div className="flex items-center gap-2 px-3 text-ui-sm font-medium text-text-secondary shrink-0" data-tauri-drag-region>
+        <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" className="text-accent">
+          <polyline points="16 18 22 12 16 6" />
+          <polyline points="8 6 2 12 8 18" />
+        </svg>
+        YACE
+      </div>
+
+      <div className="flex-1" data-tauri-drag-region />
+
+      <div className="flex h-full" data-tauri-drag-region="">
+        <button
+          onClick={() => appWindow.minimize()}
+          className="flex items-center justify-center w-[46px] h-full text-text-muted transition-colors duration-fast hover:bg-white/10 hover:text-text-primary active:bg-white/5"
+          aria-label="Minimize"
+        >
+          <MinimizeIcon />
+        </button>
+
+        <button
+          onClick={() => appWindow.toggleMaximize()}
+          className="flex items-center justify-center w-[46px] h-full text-text-muted transition-colors duration-fast hover:bg-white/10 hover:text-text-primary active:bg-white/5"
+          aria-label={isMaximized ? 'Restore' : 'Maximize'}
+        >
+          {isMaximized ? <RestoreIcon /> : <MaximizeIcon />}
+        </button>
+
+        <button
+          onClick={() => appWindow.close()}
+          className="flex items-center justify-center w-[46px] h-full text-text-muted transition-colors duration-fast hover:bg-[#e81123] hover:text-white active:bg-[#bf0f1d]"
+          aria-label="Close"
+        >
+          <CloseIcon />
+        </button>
+      </div>
+    </div>
+  )
+}
diff --git a/src/components/Toasts/Toasts.tsx b/src/components/Toasts/Toasts.tsx
new file mode 100644
index 0000000..ef3aa0d
--- /dev/null
+++ b/src/components/Toasts/Toasts.tsx
@@ -0,0 +1,72 @@
+import { useEffect, useState } from 'react'
+import { useToastStore, type ToastType } from '@/stores/useToastStore'
+
+const typeColors: Record<ToastType, string> = {
+  success: 'var(--color-semantic-success)',
+  error: 'var(--color-semantic-error)',
+  info: 'var(--color-semantic-info)',
+  warning: 'var(--color-semantic-warning)',
+}
+
+const typeIcons: Record<ToastType, string> = {
+  success: '✓',
+  error: '✗',
+  info: 'i',
+  warning: '!',
+}
+
+function ToastItem({ id, message, type }: { id: string; message: string; type: ToastType }) {
+  const [exiting, setExiting] = useState(false)
+  const removeToast = useToastStore((s) => s.removeToast)
+  const color = typeColors[type]
+
+  useEffect(() => {
+    const exitTimer = setTimeout(() => setExiting(true), 3000)
+    return () => clearTimeout(exitTimer)
+  }, [])
+
+  return (
+    <div
+      className={`flex items-start gap-2.5 min-w-[280px] max-w-[400px] px-3 py-2.5 rounded-lg shadow-glass-lg toast${exiting ? ' toast-exit' : ''}`}
+      style={{
+        backgroundColor: 'var(--color-panel-bg)',
+        border: '1px solid var(--color-panel-border)',
+        borderLeft: `3px solid ${color}`,
+      }}
+      role="alert"
+      onAnimationEnd={() => { if (exiting) removeToast(id) }}
+    >
+      <span
+        className="flex items-center justify-center w-[18px] h-[18px] mt-[1px] rounded-full text-[10px] font-bold shrink-0"
+        style={{ backgroundColor: color, color: '#fff' }}
+      >
+        {typeIcons[type]}
+      </span>
+      <span className="flex-1 text-ui-sm text-text-primary leading-[1.4]">{message}</span>
+      <button
+        className="shrink-0 text-text-muted hover:text-text-primary transition-colors duration-fast"
+        onClick={() => removeToast(id)}
+      >
+        <svg width="12" height="12" 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>
+      </button>
+    </div>
+  )
+}
+
+export default function Toasts() {
+  const toasts = useToastStore((s) => s.toasts)
+
+  if (toasts.length === 0) return null
+
+  return (
+    <div className="fixed bottom-4 right-4 z-50 flex flex-col-reverse gap-2 pointer-events-none">
+      {toasts.map((t) => (
+        <div key={t.id} className="pointer-events-auto">
+          <ToastItem id={t.id} message={t.message} type={t.type} />
+        </div>
+      ))}
+    </div>
+  )
+}
diff --git a/src/components/UI/Input.tsx b/src/components/UI/Input.tsx
new file mode 100644
index 0000000..e6a84c0
--- /dev/null
+++ b/src/components/UI/Input.tsx
@@ -0,0 +1,23 @@
+interface InputProps {
+  value: string | number
+  onChange: (value: string) => void
+  placeholder?: string
+  type?: string
+  min?: number
+  max?: number
+}
+
+export default function Input({ value, onChange, placeholder, type = 'text', min, max }: InputProps) {
+  return (
+    <input
+      type={type}
+      value={value}
+      placeholder={placeholder}
+      min={min}
+      max={max}
+      onChange={(e) => onChange(e.target.value)}
+      className="w-full h-7 px-2 rounded-md text-ui-sm text-text-primary bg-editor-surface border transition-all duration-150 outline-none placeholder:text-text-muted focus:border-accent"
+      style={{ borderColor: 'var(--color-panel-border)' }}
+    />
+  )
+}
diff --git a/src/components/UI/Slider.tsx b/src/components/UI/Slider.tsx
new file mode 100644
index 0000000..22a65ee
--- /dev/null
+++ b/src/components/UI/Slider.tsx
@@ -0,0 +1,74 @@
+import { useRef, useCallback, useEffect, useState } from 'react'
+
+interface SliderProps {
+  value: number
+  min: number
+  max: number
+  step?: number
+  onChange: (value: number) => void
+}
+
+export default function Slider({ value, min, max, step = 1, onChange }: SliderProps) {
+  const trackRef = useRef<HTMLDivElement>(null)
+  const [dragging, setDragging] = useState(false)
+
+  const pct = ((value - min) / (max - min)) * 100
+
+  const updateFromClient = useCallback((clientX: number) => {
+    const rect = trackRef.current?.getBoundingClientRect()
+    if (!rect) return
+    const raw = (clientX - rect.left) / rect.width
+    const clamped = Math.max(0, Math.min(1, raw))
+    const stepped = Math.round((min + clamped * (max - min)) / step) * step
+    onChange(Math.max(min, Math.min(max, stepped)))
+  }, [min, max, step, onChange])
+
+  const handleMouseDown = useCallback((e: React.MouseEvent) => {
+    e.preventDefault()
+    setDragging(true)
+    updateFromClient(e.clientX)
+  }, [updateFromClient])
+
+  useEffect(() => {
+    if (!dragging) return
+    const handleMove = (e: MouseEvent) => { e.preventDefault(); updateFromClient(e.clientX) }
+    const handleUp = () => setDragging(false)
+    window.addEventListener('mousemove', handleMove)
+    window.addEventListener('mouseup', handleUp)
+    return () => { window.removeEventListener('mousemove', handleMove); window.removeEventListener('mouseup', handleUp) }
+  }, [dragging, updateFromClient])
+
+  return (
+    <div
+      ref={trackRef}
+      className="relative h-4 w-full cursor-pointer flex items-center"
+      onMouseDown={handleMouseDown}
+      role="slider"
+      aria-valuemin={min}
+      aria-valuemax={max}
+      aria-valuenow={value}
+      tabIndex={0}
+      onKeyDown={(e) => {
+        if (e.key === 'ArrowRight' || e.key === 'ArrowUp') { e.preventDefault(); onChange(Math.min(max, value + step)) }
+        if (e.key === 'ArrowLeft' || e.key === 'ArrowDown') { e.preventDefault(); onChange(Math.max(min, value - step)) }
+      }}
+    >
+      <div className="absolute h-[3px] w-full rounded-full" style={{ backgroundColor: 'var(--color-panel-border)' }}>
+        <div
+          className="absolute h-full rounded-full transition-[width] duration-75"
+          style={{ width: `${pct}%`, backgroundColor: 'var(--color-accent)' }}
+        />
+      </div>
+      <div
+        className="absolute w-3.5 h-3.5 rounded-full shadow-sm border-2 transition-transform duration-75"
+        style={{
+          left: `${pct}%`,
+          marginLeft: '-7px',
+          backgroundColor: dragging ? 'var(--color-accent)' : 'var(--color-panel-bg)',
+          borderColor: 'var(--color-accent)',
+          transform: dragging ? 'scale(1.15)' : 'scale(1)',
+        }}
+      />
+    </div>
+  )
+}
diff --git a/src/components/UI/Toggle.tsx b/src/components/UI/Toggle.tsx
new file mode 100644
index 0000000..17b98e2
--- /dev/null
+++ b/src/components/UI/Toggle.tsx
@@ -0,0 +1,25 @@
+interface ToggleProps {
+  checked: boolean
+  onChange: (checked: boolean) => void
+  disabled?: boolean
+}
+
+export default function Toggle({ checked, onChange, disabled }: ToggleProps) {
+  return (
+    <button
+      role="switch"
+      aria-checked={checked}
+      disabled={disabled}
+      className="relative inline-flex h-5 w-9 shrink-0 rounded-full transition-colors duration-200 disabled:opacity-30 disabled:cursor-not-allowed focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-accent focus-visible:ring-offset-1 focus-visible:ring-offset-transparent"
+      style={{
+        backgroundColor: checked ? 'var(--color-accent)' : 'var(--color-panel-border)',
+      }}
+      onClick={() => { if (!disabled) onChange(!checked) }}
+    >
+      <span
+        className="inline-block h-[16px] w-[16px] rounded-full bg-white shadow-sm transition-transform duration-200"
+        style={{ transform: checked ? 'translateX(18px)' : 'translateX(3px)', marginTop: '2px' }}
+      />
+    </button>
+  )
+}
diff --git a/src/components/Welcome/WelcomeScreen.tsx b/src/components/Welcome/WelcomeScreen.tsx
new file mode 100644
index 0000000..13b5980
--- /dev/null
+++ b/src/components/Welcome/WelcomeScreen.tsx
@@ -0,0 +1,59 @@
+const shortcuts = [
+  { keys: ['Ctrl', 'N'], label: 'New File' },
+  { keys: ['Ctrl', 'O'], label: 'Open File' },
+  { keys: ['Ctrl', 'P'], label: 'Command Palette' },
+]
+
+function Kbd({ keys }: { keys: string[] }) {
+  return (
+    <span className="inline-flex items-center gap-0.5">
+      {keys.map((key, i) => (
+        <span key={i}>
+          {i > 0 && <span className="mx-0.5 text-text-muted text-ui-xs">+</span>}
+          <kbd
+            className="inline-flex items-center justify-center min-w-[22px] h-[18px] px-[3px] rounded text-[10px] font-mono font-medium leading-none bg-editor-surface text-text-primary border"
+            style={{ borderColor: 'var(--color-panel-border)', boxShadow: '0 1px 0 var(--color-panel-border)' }}
+          >
+            {key}
+          </kbd>
+        </span>
+      ))}
+    </span>
+  )
+}
+
+export default function WelcomeScreen() {
+  return (
+    <div className="flex-1 flex flex-col items-center justify-center select-none overflow-hidden">
+      <div className="flex flex-col items-center gap-1 mb-6">
+        <span
+          className="text-[40px] font-bold leading-none tracking-tight bg-clip-text text-transparent select-none"
+          style={{
+            backgroundImage: 'linear-gradient(135deg, var(--color-accent) 0%, var(--color-text-muted) 100%)',
+            opacity: 0.2,
+          }}
+        >
+          YACE
+        </span>
+        <span
+          className="text-[11px] leading-none text-text-muted select-none"
+          style={{ opacity: 0.35 }}
+        >
+          Yet Another Code Editor
+        </span>
+      </div>
+
+      <div className="flex flex-col gap-2">
+        {shortcuts.map((item) => (
+          <div
+            key={item.label}
+            className="flex items-center gap-3 px-3 py-1.5 rounded-md transition-all duration-150 hover:bg-panel-hover/40"
+          >
+            <Kbd keys={item.keys} />
+            <span className="text-ui-sm text-text-secondary">{item.label}</span>
+          </div>
+        ))}
+      </div>
+    </div>
+  )
+}
diff --git a/src/hooks/useCursorPosition.ts b/src/hooks/useCursorPosition.ts
new file mode 100644
index 0000000..479598d
--- /dev/null
+++ b/src/hooks/useCursorPosition.ts
@@ -0,0 +1,8 @@
+import { useTabsStore } from '@/stores/useTabsStore'
+
+export function useCursorPosition() {
+  const cursorLine = useTabsStore((s) => s.cursorLine)
+  const cursorCol = useTabsStore((s) => s.cursorCol)
+
+  return { cursorLine, cursorCol }
+}
diff --git a/src/hooks/useKeyboard.ts b/src/hooks/useKeyboard.ts
new file mode 100644
index 0000000..b1ef390
--- /dev/null
+++ b/src/hooks/useKeyboard.ts
@@ -0,0 +1,95 @@
+import { useEffect } from 'react'
+import { useTabsStore } from '@/stores/useTabsStore'
+import { useFilesStore } from '@/stores/useFilesStore'
+import { useLayoutStore } from '@/stores/useLayoutStore'
+import { useCommandStore } from '@/stores/useCommandStore'
+
+export function useKeyboard() {
+  const activeTabId = useTabsStore((s) => s.activeTabId)
+  const saveFile = useTabsStore((s) => s.saveFile)
+  const closeTab = useTabsStore((s) => s.closeTab)
+  const tabs = useTabsStore((s) => s.tabs)
+  const setActiveTab = useTabsStore((s) => s.setActiveTab)
+  const createUntitledFile = useTabsStore((s) => s.createUntitledFile)
+  const pickAndOpenFile = useTabsStore((s) => s.pickAndOpenFile)
+  const openFolder = useFilesStore((s) => s.openFolder)
+  const toggleSidePanel = useLayoutStore((s) => s.toggleSidePanel)
+  const toggleCommandPalette = useCommandStore((s) => s.toggle)
+
+  useEffect(() => {
+    async function handleKeyDown(e: KeyboardEvent) {
+      const isMod = e.ctrlKey || e.metaKey
+      if (!isMod) return
+
+      if (e.key === 'p') {
+        e.preventDefault()
+        toggleCommandPalette()
+        return
+      }
+
+      if (e.key === 'n') {
+        e.preventDefault()
+        createUntitledFile()
+        return
+      }
+
+      if (e.key === 'o' && e.shiftKey) {
+        e.preventDefault()
+        openFolder()
+        return
+      }
+
+      if (e.key === 'o') {
+        e.preventDefault()
+        pickAndOpenFile()
+        return
+      }
+
+      if (e.key === 's') {
+        e.preventDefault()
+        if (activeTabId) saveFile(activeTabId)
+        return
+      }
+
+      if (e.key === 'w') {
+        e.preventDefault()
+        if (activeTabId) closeTab(activeTabId)
+        return
+      }
+
+      if (e.key === 'b') {
+        e.preventDefault()
+        toggleSidePanel()
+        return
+      }
+
+      if (e.shiftKey && e.key === 'Tab') {
+        e.preventDefault()
+        if (tabs.length > 1 && activeTabId) {
+          const idx = tabs.findIndex((t) => t.id === activeTabId)
+          const prevIdx = idx === 0 ? tabs.length - 1 : idx - 1
+          setActiveTab(tabs[prevIdx].id)
+        }
+        return
+      }
+
+      if (e.key === 'Tab' && !e.shiftKey) {
+        e.preventDefault()
+        if (tabs.length > 1 && activeTabId) {
+          const idx = tabs.findIndex((t) => t.id === activeTabId)
+          const nextIdx = idx === tabs.length - 1 ? 0 : idx + 1
+          setActiveTab(tabs[nextIdx].id)
+        }
+        return
+      }
+
+      if (e.key === 'k' && e.shiftKey) {
+        e.preventDefault()
+        openFolder()
+      }
+    }
+
+    window.addEventListener('keydown', handleKeyDown, true)
+    return () => window.removeEventListener('keydown', handleKeyDown, true)
+  }, [activeTabId, saveFile, closeTab, tabs, setActiveTab, createUntitledFile, pickAndOpenFile, openFolder, toggleSidePanel, toggleCommandPalette])
+}
diff --git a/src/index.css b/src/index.css
new file mode 100644
index 0000000..da13c1f
--- /dev/null
+++ b/src/index.css
@@ -0,0 +1,248 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+@layer base {
+  :root {
+    --sidebar-width: 240px;
+    --tabs-height: 36px;
+    --status-height: 24px;
+
+    --color-editor-bg: #0c0c0e;
+    --color-editor-surface: #121216;
+    --color-editor-line: #19191d;
+
+    --color-panel-bg: #141417;
+    --color-panel-hover: #1c1c21;
+    --color-panel-active: #24242b;
+    --color-activity-bg: #08080a;
+    --color-panel-border: rgba(255, 255, 255, 0.03);
+
+    --color-accent: #f0a030;
+    --color-accent-hover: #f5b84a;
+    --color-accent-muted: rgba(240, 160, 48, 0.2);
+    --color-accent-text: #f5c56b;
+
+    --color-text-primary: #e8e8ed;
+    --color-text-secondary: #9b9ba3;
+    --color-text-muted: #7a7a82;
+
+    --color-semantic-error: #e34c4c;
+    --color-semantic-warning: #f0a030;
+    --color-semantic-info: #42a5f5;
+    --color-semantic-success: #4caf50;
+
+    --color-ruler: rgba(255, 255, 255, 0.06);
+
+    --shadow-sm: 0 1px 2px rgba(0,0,0,0.35);
+    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.35), 0 2px 4px -2px rgba(0,0,0,0.25);
+    --shadow-lg: 0 4px 6px rgba(0,0,0,0.3), 0 10px 30px rgba(0,0,0,0.2);
+    --shadow-xl: 0 8px 12px rgba(0,0,0,0.3), 0 18px 50px rgba(0,0,0,0.18);
+    --shadow-2xl: 0 12px 24px rgba(0,0,0,0.3), 0 24px 64px rgba(0,0,0,0.18);
+  }
+
+  [data-theme="light"] {
+    --color-editor-bg: #fafbfc;
+    --color-editor-surface: #f0f2f5;
+    --color-editor-line: #e8eaed;
+
+    --color-panel-bg: #f3f4f6;
+    --color-panel-hover: #e5e7eb;
+    --color-panel-active: #d1d5db;
+    --color-activity-bg: #e8eaed;
+    --color-panel-border: rgba(0, 0, 0, 0.03);
+
+    --color-accent: #d97706;
+    --color-accent-hover: #b45309;
+    --color-accent-muted: rgba(217, 119, 6, 0.15);
+    --color-accent-text: #92400e;
+
+    --color-text-primary: #111827;
+    --color-text-secondary: #4b5563;
+    --color-text-muted: #6b7280;
+
+    --color-semantic-error: #dc2626;
+    --color-semantic-warning: #d97706;
+    --color-semantic-info: #2563eb;
+    --color-semantic-success: #16a34a;
+
+    --color-ruler: rgba(0, 0, 0, 0.06);
+
+    --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
+    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.06), 0 2px 4px -2px rgba(0,0,0,0.04);
+    --shadow-lg: 0 4px 6px rgba(0,0,0,0.05), 0 10px 30px rgba(0,0,0,0.04);
+    --shadow-xl: 0 8px 12px rgba(0,0,0,0.05), 0 18px 50px rgba(0,0,0,0.04);
+    --shadow-2xl: 0 12px 24px rgba(0,0,0,0.06), 0 24px 64px rgba(0,0,0,0.05);
+  }
+
+  html, body, #root {
+    @apply m-0 p-0 h-full overflow-hidden;
+  }
+
+  html {
+    overscroll-behavior: none;
+    -webkit-font-smoothing: antialiased;
+    -moz-osx-font-smoothing: grayscale;
+    text-rendering: optimizeLegibility;
+    scrollbar-width: thin;
+  }
+
+  body {
+    @apply font-ui antialiased;
+    background-color: var(--color-editor-bg);
+    color: var(--color-text-primary);
+    user-select: none;
+    -webkit-user-select: none;
+  }
+
+  body, body * {
+    transition: background-color 0.25s ease,
+                color 0.25s ease,
+                border-color 0.25s ease,
+                box-shadow 0.25s ease;
+  }
+
+  * {
+    -webkit-tap-highlight-color: transparent;
+  }
+
+  svg, img {
+    -webkit-user-drag: none;
+    user-select: none;
+  }
+
+  .cm-editor, .cm-editor * {
+    user-select: text;
+    -webkit-user-select: text;
+  }
+
+  .cm-editor {
+    line-height: 1.6;
+    letter-spacing: 0;
+    font-variant-ligatures: normal;
+    -webkit-font-smoothing: antialiased;
+    -moz-osx-font-smoothing: grayscale;
+  }
+
+  .cm-scroller {
+    scroll-behavior: auto;
+  }
+
+  .cm-content {
+    padding: 0;
+  }
+
+  .cm-line {
+    padding: 0;
+  }
+
+  *:focus-visible {
+    outline: 2px solid var(--color-accent);
+    outline-offset: -2px;
+  }
+
+  .focus-ring:focus-visible {
+    outline: 2px solid var(--color-accent);
+    outline-offset: 2px;
+  }
+
+  *::selection {
+    background-color: var(--color-accent-muted);
+  }
+
+  *::-webkit-scrollbar {
+    width: 4px;
+    height: 4px;
+  }
+
+  *::-webkit-scrollbar-track {
+    background: transparent;
+  }
+
+  *::-webkit-scrollbar-thumb {
+    background: var(--color-panel-border);
+    border-radius: 4px;
+    transition: opacity 0.2s ease, background-color 0.15s ease;
+    opacity: 0;
+  }
+
+  *:hover::-webkit-scrollbar-thumb {
+    opacity: 0.7;
+  }
+
+  *::-webkit-scrollbar-thumb:hover {
+    opacity: 1;
+    background: var(--color-text-muted);
+  }
+
+  *::-webkit-scrollbar-thumb:active {
+    opacity: 1;
+    background: var(--color-text-secondary);
+  }
+
+  .cm-scroller::-webkit-scrollbar-thumb {
+    opacity: 0.4;
+  }
+
+  .cm-scroller:hover::-webkit-scrollbar-thumb {
+    opacity: 0.8;
+  }
+
+  .shadow-glass {
+    box-shadow: var(--shadow-2xl);
+  }
+
+  .shadow-glass-lg {
+    box-shadow: var(--shadow-lg);
+  }
+
+  .panel-mica {
+    background:
+      linear-gradient(180deg, rgba(255, 255, 255, 0.02) 0%, transparent 40%),
+      var(--color-panel-bg);
+  }
+
+  [data-theme="light"] .panel-mica {
+    background:
+      linear-gradient(180deg, rgba(255, 255, 255, 0.6) 0%, transparent 40%),
+      var(--color-panel-bg);
+  }
+
+  .backdrop-glass {
+    background-color: rgba(0, 0, 0, 0.55);
+    backdrop-filter: blur(12px);
+    -webkit-backdrop-filter: blur(12px);
+  }
+
+  [data-theme="light"] .backdrop-glass {
+    background-color: rgba(0, 0, 0, 0.08);
+  }
+
+  @keyframes contextMenuIn {
+    from { opacity: 0; transform: scale(0.95); }
+    to { opacity: 1; transform: scale(1); }
+  }
+
+  .context-menu {
+    animation: contextMenuIn 0.12s ease-out;
+    transform-origin: top left;
+  }
+
+  @keyframes toastIn {
+    from { opacity: 0; transform: translateY(16px) scale(0.96); }
+    to { opacity: 1; transform: translateY(0) scale(1); }
+  }
+
+  @keyframes toastOut {
+    from { opacity: 1; transform: translateY(0) scale(1); }
+    to { opacity: 0; transform: translateY(8px) scale(0.96); }
+  }
+
+  .toast {
+    animation: toastIn 0.25s ease-out;
+  }
+
+  .toast.toast-exit {
+    animation: toastOut 0.2s ease-in forwards;
+  }
+}
diff --git a/src/lib/languageMap.ts b/src/lib/languageMap.ts
new file mode 100644
index 0000000..ec8d6b7
--- /dev/null
+++ b/src/lib/languageMap.ts
@@ -0,0 +1,23 @@
+import type { Language } from '@/types'
+
+const extensionMap: Record<string, Language> = {
+  ts: 'typescript',
+  tsx: 'typescript',
+  js: 'javascript',
+  jsx: 'javascript',
+  mjs: 'javascript',
+  cjs: 'javascript',
+  rs: 'rust',
+  json: 'json',
+  md: 'markdown',
+  mdx: 'markdown',
+  html: 'html',
+  htm: 'html',
+  css: 'css',
+  py: 'python',
+}
+
+export function detectLanguage(filename: string): Language {
+  const ext = filename.split('.').pop()?.toLowerCase() ?? ''
+  return extensionMap[ext] ?? 'plaintext'
+}
diff --git a/src/lib/tauri.ts b/src/lib/tauri.ts
new file mode 100644
index 0000000..294f117
--- /dev/null
+++ b/src/lib/tauri.ts
@@ -0,0 +1,46 @@
+import { invoke } from '@tauri-apps/api/tauri'
+import type { FileEntry } from '@/types'
+
+export async function readFile(path: string): Promise<string> {
+  return invoke<string>('read_file', { path })
+}
+
+export async function writeFile(path: string, content: string): Promise<void> {
+  return invoke<void>('write_file', { path, content })
+}
+
+export async function openDir(path: string): Promise<FileEntry[]> {
+  return invoke<FileEntry[]>('open_dir', { path })
+}
+
+export async function pickDirectory(): Promise<string | null> {
+  const { open } = await import('@tauri-apps/api/dialog')
+  const selected = await open({
+    directory: true,
+    multiple: false,
+    title: 'Open Folder',
+  })
+  return selected as string | null
+}
+
+export async function createDir(path: string): Promise<void> {
+  return invoke<void>('create_dir', { path })
+}
+
+export async function pickFile(): Promise<string | null> {
+  const { open } = await import('@tauri-apps/api/dialog')
+  const selected = await open({
+    multiple: false,
+    title: 'Open File',
+  })
+  return (selected as string) ?? null
+}
+
+export async function saveDialog(defaultName?: string): Promise<string | null> {
+  const { save } = await import('@tauri-apps/api/dialog')
+  const selected = await save({
+    defaultPath: defaultName,
+    title: 'Save File',
+  })
+  return selected ?? null
+}
diff --git a/src/main.tsx b/src/main.tsx
new file mode 100644
index 0000000..964aeb4
--- /dev/null
+++ b/src/main.tsx
@@ -0,0 +1,10 @@
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import App from './App'
+import './index.css'
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>,
+)
diff --git a/src/stores/useCommandStore.ts b/src/stores/useCommandStore.ts
new file mode 100644
index 0000000..2975436
--- /dev/null
+++ b/src/stores/useCommandStore.ts
@@ -0,0 +1,137 @@
+import { create } from 'zustand'
+import { useTabsStore } from './useTabsStore'
+import { useFilesStore } from './useFilesStore'
+import { useLayoutStore } from './useLayoutStore'
+
+export interface Command {
+  id: string
+  label: string
+  shortcut?: string
+  category: string
+  action: () => void
+}
+
+export interface CommandState {
+  isOpen: boolean
+  query: string
+  selectedIndex: number
+  commands: Command[]
+  open: () => void
+  close: () => void
+  toggle: () => void
+  setQuery: (query: string) => void
+  setSelectedIndex: (index: number) => void
+  executeSelected: () => void
+}
+
+function buildCommands(): Command[] {
+  const filesStore = useFilesStore.getState()
+  const layoutStore = useLayoutStore.getState()
+
+  return [
+    {
+      id: 'open-folder',
+      label: 'Open Folder',
+      shortcut: 'Ctrl+Shift+K',
+      category: 'File',
+      action: () => filesStore.openFolder(),
+    },
+    {
+      id: 'toggle-sidebar',
+      label: 'Toggle Sidebar',
+      shortcut: 'Ctrl+B',
+      category: 'View',
+      action: () => layoutStore.toggleSidePanel(),
+    },
+    {
+      id: 'save-file',
+      label: 'Save File',
+      shortcut: 'Ctrl+S',
+      category: 'File',
+      action: () => {
+        const state = useTabsStore.getState()
+        if (state.activeTabId) state.saveFile(state.activeTabId)
+      },
+    },
+    {
+      id: 'close-tab',
+      label: 'Close Current Tab',
+      shortcut: 'Ctrl+W',
+      category: 'File',
+      action: () => {
+        const state = useTabsStore.getState()
+        if (state.activeTabId) state.closeTab(state.activeTabId)
+      },
+    },
+    {
+      id: 'close-all-tabs',
+      label: 'Close All Tabs',
+      shortcut: '',
+      category: 'File',
+      action: () => {
+        const state = useTabsStore.getState()
+        state.tabs.forEach((t) => state.closeTab(t.id))
+      },
+    },
+    {
+      id: 'show-explorer',
+      label: 'Focus Explorer',
+      shortcut: '',
+      category: 'View',
+      action: () => layoutStore.setActiveView('explorer'),
+    },
+    {
+      id: 'show-search',
+      label: 'Show Search',
+      shortcut: '',
+      category: 'View',
+      action: () => layoutStore.setActiveView('search'),
+    },
+  ]
+}
+
+export const useCommandStore = create<CommandState>((set, get) => ({
+  isOpen: false,
+  query: '',
+  selectedIndex: 0,
+  commands: [],
+
+  open: () => {
+    set({ isOpen: true, query: '', selectedIndex: 0, commands: buildCommands() })
+  },
+
+  close: () => {
+    set({ isOpen: false, query: '', selectedIndex: 0 })
+  },
+
+  toggle: () => {
+    const { isOpen } = get()
+    if (isOpen) {
+      get().close()
+    } else {
+      get().open()
+    }
+  },
+
+  setQuery: (query: string) => {
+    set({ query, selectedIndex: 0 })
+  },
+
+  setSelectedIndex: (index: number) => {
+    set({ selectedIndex: index })
+  },
+
+  executeSelected: () => {
+    const { commands, query, selectedIndex } = get()
+    const filtered = commands.filter(
+      (c) =>
+        c.label.toLowerCase().includes(query.toLowerCase()) ||
+        c.category.toLowerCase().includes(query.toLowerCase())
+    )
+    const cmd = filtered[selectedIndex]
+    if (cmd) {
+      cmd.action()
+      get().close()
+    }
+  },
+}))
diff --git a/src/stores/useContextMenuStore.ts b/src/stores/useContextMenuStore.ts
new file mode 100644
index 0000000..a0fd2cf
--- /dev/null
+++ b/src/stores/useContextMenuStore.ts
@@ -0,0 +1,31 @@
+import { create } from 'zustand'
+
+export type ContextMenuIcon = 'copy' | 'cut' | 'paste' | 'undo' | 'redo' | 'selectAll' | 'close' | 'folder' | 'file' | 'link' | 'rename' | 'trash'
+
+export interface ContextMenuItem {
+  id: string
+  label: string
+  shortcut?: string
+  icon?: ContextMenuIcon
+  action: () => void
+  disabled?: boolean
+  separator?: boolean
+}
+
+interface ContextMenuState {
+  isOpen: boolean
+  x: number
+  y: number
+  items: ContextMenuItem[]
+  open: (x: number, y: number, items: ContextMenuItem[]) => void
+  close: () => void
+}
+
+export const useContextMenuStore = create<ContextMenuState>((set) => ({
+  isOpen: false,
+  x: 0,
+  y: 0,
+  items: [],
+  open: (x, y, items) => set({ isOpen: true, x, y, items }),
+  close: () => set({ isOpen: false }),
+}))
diff --git a/src/stores/useFilesStore.ts b/src/stores/useFilesStore.ts
new file mode 100644
index 0000000..200fb68
--- /dev/null
+++ b/src/stores/useFilesStore.ts
@@ -0,0 +1,84 @@
+import { create } from 'zustand'
+import type { FileEntry } from '@/types'
+import { openDir, pickDirectory, writeFile, createDir } from '@/lib/tauri'
+
+interface FilesState {
+  fileTree: FileEntry[]
+  rootPath: string | null
+  loading: boolean
+  openFolder: () => Promise<void>
+  loadFolder: (path: string) => Promise<void>
+  createFile: (parentPath?: string) => Promise<string | null>
+  createFolder: (parentPath?: string) => Promise<string | null>
+}
+
+function generateName(base: string, existing: string[]): string {
+  const used = new Set(existing)
+  let name = base
+  let counter = 1
+  while (used.has(name)) {
+    name = `${base} ${counter++}`
+  }
+  return name
+}
+
+function collectNames(entries: FileEntry[]): string[] {
+  const names: string[] = []
+  for (const e of entries) {
+    names.push(e.name)
+  }
+  return names
+}
+
+export const useFilesStore = create<FilesState>((set, get) => ({
+  fileTree: [],
+  rootPath: null,
+  loading: false,
+
+  openFolder: async () => {
+    const path = await pickDirectory()
+    if (!path) return
+    set({ rootPath: path, loading: true })
+    localStorage.setItem('yace_last_folder', path)
+    try {
+      const entries = await openDir(path)
+      set({ fileTree: entries, loading: false })
+    } catch {
+      set({ loading: false })
+    }
+  },
+
+  loadFolder: async (path: string) => {
+    set({ loading: true })
+    try {
+      const entries = await openDir(path)
+      set({ fileTree: entries, rootPath: path, loading: false })
+    } catch {
+      set({ loading: false })
+    }
+  },
+
+  createFile: async (parentPath?: string): Promise<string | null> => {
+    const { rootPath, fileTree } = get()
+    if (!rootPath) return null
+    const targetDir = parentPath ?? rootPath
+    const name = generateName('Untitled-1', collectNames(fileTree))
+    const filePath = `${targetDir}\\${name}`
+    await writeFile(filePath, '')
+    const entries = await openDir(rootPath)
+    set({ fileTree: entries })
+    return filePath
+  },
+
+  createFolder: async (parentPath?: string): Promise<string | null> => {
+    const { rootPath, fileTree } = get()
+    if (!rootPath) return null
+    const targetDir = parentPath ?? rootPath
+    const name = generateName('New Folder', collectNames(fileTree))
+    const dirPath = `${targetDir}\\${name}`
+    await createDir(dirPath)
+    const entries = await openDir(rootPath)
+    set({ fileTree: entries })
+    return dirPath
+  },
+}))
diff --git a/src/stores/useLayoutStore.ts b/src/stores/useLayoutStore.ts
new file mode 100644
index 0000000..adcdae7
--- /dev/null
+++ b/src/stores/useLayoutStore.ts
@@ -0,0 +1,51 @@
+import { create } from 'zustand'
+
+export type ActivityView = 'explorer' | 'search' | 'extensions' | 'settings'
+
+interface LayoutState {
+  activeView: ActivityView | null
+  sidePanelVisible: boolean
+  sidePanelWidth: number
+  setActiveView: (view: ActivityView | null) => void
+  toggleSidePanel: () => void
+  showSidePanel: () => void
+  hideSidePanel: () => void
+  setSidePanelWidth: (width: number) => void
+}
+
+const SIDEPANEL_MIN = 180
+const SIDEPANEL_MAX = 500
+const SIDEPANEL_DEFAULT = 240
+
+export const useLayoutStore = create<LayoutState>((set, get) => ({
+  activeView: 'explorer',
+  sidePanelVisible: true,
+  sidePanelWidth: SIDEPANEL_DEFAULT,
+
+  setActiveView: (view: ActivityView | null) => {
+    const { activeView, hideSidePanel, showSidePanel } = get()
+    if (activeView === view) {
+      hideSidePanel()
+      set({ activeView: null })
+    } else {
+      set({ activeView: view })
+      showSidePanel()
+    }
+  },
+
+  toggleSidePanel: () => {
+    set((s) => ({ sidePanelVisible: !s.sidePanelVisible }))
+  },
+
+  showSidePanel: () => {
+    set({ sidePanelVisible: true })
+  },
+
+  hideSidePanel: () => {
+    set({ sidePanelVisible: false })
+  },
+
+  setSidePanelWidth: (width: number) => {
+    set({ sidePanelWidth: Math.max(SIDEPANEL_MIN, Math.min(SIDEPANEL_MAX, width)) })
+  },
+}))
diff --git a/src/stores/useSettingsStore.ts b/src/stores/useSettingsStore.ts
new file mode 100644
index 0000000..7f2be4f
--- /dev/null
+++ b/src/stores/useSettingsStore.ts
@@ -0,0 +1,34 @@
+import { create } from 'zustand'
+import { persist } from 'zustand/middleware'
+
+interface SettingsState {
+  fontSize: number
+  tabSize: number
+  fontFamily: string
+  wordWrap: boolean
+  lineNumbers: boolean
+  ruler: boolean
+  rulerColumn: number
+  autoSave: boolean
+  autoSaveDelay: number
+
+  set: <K extends keyof SettingsState>(key: K, value: SettingsState[K]) => void
+}
+
+export const useSettingsStore = create<SettingsState>()(
+  persist(
+    (set) => ({
+      fontSize: 14,
+      tabSize: 2,
+      fontFamily: 'JetBrains Mono',
+      wordWrap: true,
+      lineNumbers: true,
+      ruler: true,
+      rulerColumn: 80,
+      autoSave: false,
+      autoSaveDelay: 2000,
+      set: (key, value) => set({ [key]: value }),
+    }),
+    { name: 'yace-settings' }
+  )
+)
diff --git a/src/stores/useTabsStore.ts b/src/stores/useTabsStore.ts
new file mode 100644
index 0000000..eb9a03a
--- /dev/null
+++ b/src/stores/useTabsStore.ts
@@ -0,0 +1,152 @@
+import { create } from 'zustand'
+import type { Tab } from '@/types'
+import { readFile, writeFile, saveDialog, pickFile } from '@/lib/tauri'
+import { detectLanguage } from '@/lib/languageMap'
+
+interface TabsState {
+  tabs: Tab[]
+  activeTabId: string | null
+  cursorLine: number
+  cursorCol: number
+  savingId: string | null
+  statusMessage: string | null
+  untitledCounter: number
+
+  openFile: (path: string) => Promise<void>
+  pickAndOpenFile: () => Promise<void>
+  createUntitledFile: () => void
+  closeTab: (id: string) => void
+  setActiveTab: (id: string) => void
+  updateContent: (id: string, content: string) => void
+  saveFile: (id: string) => Promise<void>
+  setCursorPosition: (line: number, col: number) => void
+  clearStatusMessage: () => void
+}
+
+function isUntitled(id: string) {
+  return id.startsWith('untitled://')
+}
+
+export const useTabsStore = create<TabsState>((set, get) => ({
+  tabs: [],
+  activeTabId: null,
+  cursorLine: 1,
+  cursorCol: 1,
+  savingId: null,
+  statusMessage: null,
+  untitledCounter: 0,
+
+  openFile: async (path: string) => {
+    const { tabs } = get()
+    const existing = tabs.find((t) => t.path === path)
+    if (existing) {
+      set({ activeTabId: existing.id })
+      return
+    }
+
+    try {
+      const content = await readFile(path)
+      const name = path.split(/[\\/]/).pop() ?? 'untitled'
+      const id = path
+      const tab: Tab = {
+        id,
+        path,
+        name,
+        language: detectLanguage(name),
+        content,
+        modified: false,
+      }
+      set({ tabs: [...tabs, tab], activeTabId: id })
+    } catch (err) {
+      console.error('Failed to open file:', err)
+    }
+  },
+
+  pickAndOpenFile: async () => {
+    const path = await pickFile()
+    if (path) get().openFile(path)
+  },
+
+  createUntitledFile: () => {
+    const { tabs, untitledCounter } = get()
+    const n = untitledCounter + 1
+    const name = `Untitled-${n}`
+    const id = `untitled://${n}`
+    const tab: Tab = {
+      id,
+      path: id,
+      name,
+      language: 'plaintext',
+      content: '',
+      modified: false,
+    }
+    set({ tabs: [...tabs, tab], activeTabId: id, untitledCounter: n })
+  },
+
+  closeTab: (id: string) => {
+    const { tabs, activeTabId } = get()
+    const newTabs = tabs.filter((t) => t.id !== id)
+    let newActive = activeTabId
+    if (activeTabId === id) {
+      const idx = tabs.findIndex((t) => t.id === id)
+      newActive = newTabs[Math.min(idx, newTabs.length - 1)]?.id ?? null
+    }
+    set({ tabs: newTabs, activeTabId: newActive })
+  },
+
+  setActiveTab: (id: string) => {
+    set({ activeTabId: id })
+  },
+
+  updateContent: (id: string, content: string) => {
+    set((state) => ({
+      tabs: state.tabs.map((t) =>
+        t.id === id ? { ...t, content, modified: true } : t
+      ),
+    }))
+  },
+
+  saveFile: async (id: string) => {
+    const { tabs } = get()
+    const tab = tabs.find((t) => t.id === id)
+    if (!tab) return
+
+    set({ savingId: id, statusMessage: null })
+
+    try {
+      let targetPath = tab.path
+
+      if (isUntitled(targetPath)) {
+        const picked = await saveDialog(tab.name)
+        if (!picked) {
+          set({ savingId: null })
+          return
+        }
+        targetPath = picked
+      }
+
+      await writeFile(targetPath, tab.content)
+      const name = targetPath.split(/[\\/]/).pop() ?? tab.name
+      set({
+        tabs: tabs.map((t) =>
+          t.id === id
+            ? { ...t, path: targetPath, name, language: detectLanguage(name), modified: false }
+            : t
+        ),
+        savingId: null,
+        statusMessage: 'Saved',
+      })
+    } catch (err) {
+      set({ savingId: null, statusMessage: 'Save failed' })
+      console.error('Failed to save file:', err)
+    }
+  },
+
+  setCursorPosition: (line: number, col: number) => {
+    set({ cursorLine: line, cursorCol: col })
+  },
+
+  clearStatusMessage: () => {
+    set({ statusMessage: null })
+  },
+}))
diff --git a/src/stores/useThemeStore.ts b/src/stores/useThemeStore.ts
new file mode 100644
index 0000000..d9c3d06
--- /dev/null
+++ b/src/stores/useThemeStore.ts
@@ -0,0 +1,41 @@
+import { create } from 'zustand'
+
+export type Theme = 'dark' | 'light'
+
+interface ThemeState {
+  theme: Theme
+  setTheme: (theme: Theme) => void
+  toggleTheme: () => void
+}
+
+function getInitialTheme(): Theme {
+  const stored = localStorage.getItem('yace_theme')
+  if (stored === 'light' || stored === 'dark') return stored
+  return 'dark'
+}
+
+function applyTheme(theme: Theme) {
+  document.documentElement.setAttribute('data-theme', theme)
+}
+
+const initial = getInitialTheme()
+applyTheme(initial)
+
+export const useThemeStore = create<ThemeState>((set) => ({
+  theme: initial,
+
+  setTheme: (theme: Theme) => {
+    applyTheme(theme)
+    localStorage.setItem('yace_theme', theme)
+    set({ theme })
+  },
+
+  toggleTheme: () => {
+    set((state) => {
+      const next = state.theme === 'dark' ? 'light' : 'dark'
+      applyTheme(next)
+      localStorage.setItem('yace_theme', next)
+      return { theme: next }
+    })
+  },
+}))
diff --git a/src/stores/useToastStore.ts b/src/stores/useToastStore.ts
new file mode 100644
index 0000000..ab45325
--- /dev/null
+++ b/src/stores/useToastStore.ts
@@ -0,0 +1,31 @@
+import { create } from 'zustand'
+
+export type ToastType = 'success' | 'error' | 'info' | 'warning'
+
+export interface Toast {
+  id: string
+  message: string
+  type: ToastType
+}
+
+interface ToastState {
+  toasts: Toast[]
+  addToast: (message: string, type?: ToastType, duration?: number) => void
+  removeToast: (id: string) => void
+}
+
+let counter = 0
+
+export const useToastStore = create<ToastState>((set, get) => ({
+  toasts: [],
+  addToast: (message, type = 'info', duration = 3500) => {
+    const id = `toast-${++counter}`
+    set((s) => ({ toasts: [...s.toasts, { id, message, type }] }))
+    setTimeout(() => {
+      get().removeToast(id)
+    }, duration)
+  },
+  removeToast: (id) => {
+    set((s) => ({ toasts: s.toasts.filter((t) => t.id !== id) }))
+  },
+}))
diff --git a/src/types/index.ts b/src/types/index.ts
new file mode 100644
index 0000000..3a822ae
--- /dev/null
+++ b/src/types/index.ts
@@ -0,0 +1,26 @@
+export interface FileEntry {
+  name: string
+  path: string
+  is_dir: boolean
+  children?: FileEntry[]
+}
+
+export interface Tab {
+  id: string
+  path: string
+  name: string
+  language: string
+  content: string
+  modified: boolean
+}
+
+export type Language =
+  | 'typescript'
+  | 'javascript'
+  | 'rust'
+  | 'json'
+  | 'markdown'
+  | 'html'
+  | 'css'
+  | 'python'
+  | 'plaintext'
diff --git a/src/vite-env.d.ts b/src/vite-env.d.ts
new file mode 100644
index 0000000..11f02fe
--- /dev/null
+++ b/src/vite-env.d.ts
@@ -0,0 +1 @@
+/// <reference types="vite/client" />