@media (max-width: 768px) {
  #order-standard_cart .secondary-cart-sidebar,
  #order-standard_cart .cart-sidebar,
  #order-standard_cart .sidebar,
  #order-standard_cart .col-md-3,
  #order-standard_cart .panel-sidebar {
    display: none !important;
  }

  #order-standard_cart .col-md-9,
  #order-standard_cart .main-content,
  #order-standard_cart .cart-body {
    width: 100% !important;
    max-width: 100% !important;
    flex: 0 0 100% !important;
  }
}