const KEY = 'prefs';

function loadPrefs() {
  try {
    return JSON.parse(localStorage.getItem(KEY)) || {};
  } catch {
    return {};
  }
}

function savePrefs(p) {
  localStorage.setItem(KEY, JSON.stringify(p));
}

const prefs = loadPrefs();
prefs.theme = 'dark';
savePrefs(prefs);