@media (max-width: 820px) {
  .shell { display: block; }
  .sidebar { left: 0; width: 230px; transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .main { width: 100%; }
  .modal-bg { left: 0; width: 100vw; justify-content: stretch; }
  .drawer { width: 100vw; max-width: 100vw; min-width: 0; margin: 0; }
}