type Theme = "light" | "dark";

type ThemeContextValue = {
  theme: Theme;
  setTheme: (t: Theme) => void;
};

const ThemeContext = React.createContext<ThemeContextValue | null>(null);

function useTheme(): ThemeContextValue {
  const ctx = React.useContext(ThemeContext);
  if (!ctx) throw new Error("ThemeProvider missing");
  return ctx;
}