zroc/zroc-ui/src/auth/ThemeContext.jsx

// src/auth/ThemeContext.jsx
import { createContext, useContext, useState, useEffect } from 'react';

const ThemeContext = createContext(null);

export function ThemeProvider({ children }) {
  const [theme, setTheme] = useState(() =>
    localStorage.getItem('zroc-theme') || 'dark'
  );

  useEffect(() => {
    document.documentElement.setAttribute('data-theme', theme);
    localStorage.setItem('zroc-theme', theme);
  }, [theme]);

  const toggle = () => setTheme((t) => t === 'dark' ? 'light' : 'dark');

  return (
    <ThemeContext.Provider value={{ theme, toggle }}>
      {children}
    </ThemeContext.Provider>
  );
}

export function useTheme() {
  const ctx = useContext(ThemeContext);
  if (!ctx) throw new Error('useTheme must be used within ThemeProvider');
  return ctx;
}