options.js

function saveOptions(e) {
  e.preventDefault();
  browser.storage.local.set({
    foreground: document.querySelector('#foreground').checked,
    suppressConfirm: document.querySelector('#suppress-confirm').checked,
    markRead: document.querySelector('#mark-read').checked,
    openSaved: document.querySelector('#open-saved').checked,
  });
}

async function restoreOptions() {
  const storage = await browser.storage.local.get();
  document.querySelector('#foreground').checked = storage.foreground;
  document.querySelector('#suppress-confirm').checked = storage.suppressConfirm;
  document.querySelector('#mark-read').checked = storage.markRead;
  document.querySelector('#open-saved').checked = storage.openSaved;
}

document.addEventListener('DOMContentLoaded', restoreOptions);
document.querySelector('form').addEventListener('submit', saveOptions);