Document pages are loaded in a sandboxed iframe. HotelDesk injects 12 px typography, compact controls, 3 px radius, light/dark palette and CSS variables such as --hd-bg, --hd-surface, --hd-border, --hd-text, --hd-orange and --hd-blue.
Use window.HotelDeskPlugin.invoke(action,payload) for your backend and host(action,payload) for allowed host actions: navigation:pluginPage, printing:list, printing:print, printing:savePdf, file:saveText and external:open.
Remote pages must accept hoteldesk_embed/design/theme/language query parameters and answer the design-ready message within the allowed time.