@media (max-width: 720px) {
  .shell {
    width: min(100vw - 18px, 1536px);
    margin: 9px auto;
  }

  .app-card {
    padding: 16px;
  }

  .grid.two,
  .grid.four,
  .room-grid,
  .lobby-grid,
  .auth-layout {
    grid-template-columns: 1fr;
  }

  .slider-line,
  .chat-input {
    grid-template-columns: 1fr;
  }

  .top-actions .btn,
  .theme-chip {
    width: 100%;
  }
}