import React, { createContext, useContext, useState } from 'react'; const ThemeContext = createContext(); export function ThemeProvider({ children }) { const [theme, setTheme] = useState( localStorage.getItem('theme') || 'dark' // document.body.className = theme; ); const updateTheme = newTheme => { setTheme(newTheme); localStorage.setItem('theme', newTheme); }; return ( {children} ); } export function useTheme() { return useContext(ThemeContext); }