diff --git a/sundynix-admin/src/site/components/layout/site-header.tsx b/sundynix-admin/src/site/components/layout/site-header.tsx
index 93aff17..dcaa2c5 100644
--- a/sundynix-admin/src/site/components/layout/site-header.tsx
+++ b/sundynix-admin/src/site/components/layout/site-header.tsx
@@ -1,34 +1,17 @@
 import { useState } from 'react'
 import { Link, NavLink } from 'react-router-dom'
-import { Menu, Moon, Sun, X } from 'lucide-react'
-import { useTheme } from '@/components/theme-provider'
+import { Menu, X } from 'lucide-react'
 import { LogoMark } from '@/components/logo'
 import { cn } from '@/lib/utils'
 
+// 官网默认浅色，不搬深浅切换（ThemeProvider 未挂载）。
+
 const NAV_ITEMS = [
   { label: '产品', to: '/', end: true },
   { label: '功能', to: '/#features' },
   { label: '架构', to: '/#architecture' },
 ]
 
-function ThemeToggle() {
-  const { resolved, setTheme } = useTheme()
-  return (
-    <button
-      type="button"
-      aria-label={resolved === 'dark' ? '切换到浅色主题' : '切换到深色主题'}
-      onClick={() => setTheme(resolved === 'dark' ? 'light' : 'dark')}
-      className="flex size-8 items-center justify-center rounded-full border border-hairline-strong text-ink-2 transition-colors hover:border-accent hover:text-accent-ink"
-    >
-      {resolved === 'dark' ? (
-        <Sun className="size-4" />
-      ) : (
-        <Moon className="size-4" />
-      )}
-    </button>
-  )
-}
-
 export function SiteHeader() {
   const [open, setOpen] = useState(false)
 
@@ -70,7 +53,6 @@ export function SiteHeader() {
 
         <nav className="hidden items-center gap-7 md:flex">
           {links}
-          <ThemeToggle />
           <Link
             to="/download"
             className="rounded-[7px] bg-accent px-4 py-1.5 text-[13px] font-medium text-ground transition-opacity hover:opacity-90"
@@ -80,7 +62,6 @@ export function SiteHeader() {
         </nav>
 
         <div className="flex items-center gap-3 md:hidden">
-          <ThemeToggle />
           <button
             type="button"
             aria-label={open ? '关闭菜单' : '打开菜单'}
diff --git a/sundynix-admin/src/site/components/theme-provider.tsx b/sundynix-admin/src/site/components/theme-provider.tsx
deleted file mode 100644
index dc3be00..0000000
--- a/sundynix-admin/src/site/components/theme-provider.tsx
+++ /dev/null
@@ -1,63 +0,0 @@
-import {
-  createContext,
-  useContext,
-  useEffect,
-  useState,
-  type ReactNode,
-} from 'react'
-
-type Theme = 'light' | 'dark' | 'system'
-
-interface ThemeContextValue {
-  theme: Theme
-  resolved: 'light' | 'dark'
-  setTheme: (t: Theme) => void
-}
-
-const ThemeContext = createContext<ThemeContextValue | null>(null)
-
-const STORAGE_KEY = 'sundynix-theme'
-
-function systemTheme(): 'light' | 'dark' {
-  return window.matchMedia('(prefers-color-scheme: dark)').matches
-    ? 'dark'
-    : 'light'
-}
-
-export function ThemeProvider({ children }: { children: ReactNode }) {
-  const [theme, setThemeState] = useState<Theme>(
-    () => (localStorage.getItem(STORAGE_KEY) as Theme) ?? 'system',
-  )
-  const [resolved, setResolved] = useState<'light' | 'dark'>(() =>
-    theme === 'system' ? systemTheme() : theme,
-  )
-
-  useEffect(() => {
-    const apply = () => {
-      const r = theme === 'system' ? systemTheme() : theme
-      setResolved(r)
-      document.documentElement.classList.toggle('dark', r === 'dark')
-    }
-    apply()
-    const mq = window.matchMedia('(prefers-color-scheme: dark)')
-    mq.addEventListener('change', apply)
-    return () => mq.removeEventListener('change', apply)
-  }, [theme])
-
-  const setTheme = (t: Theme) => {
-    localStorage.setItem(STORAGE_KEY, t)
-    setThemeState(t)
-  }
-
-  return (
-    <ThemeContext.Provider value={{ theme, resolved, setTheme }}>
-      {children}
-    </ThemeContext.Provider>
-  )
-}
-
-export function useTheme() {
-  const ctx = useContext(ThemeContext)
-  if (!ctx) throw new Error('useTheme must be used within ThemeProvider')
-  return ctx
-}