cross-device-checklisted

# Cross-Device Check Test the supported environment, not a device label. Reproduce each defect under the capabilities and display conditions that trigger it. ## 1. Establish the support matrix Inspect the engine or runtime, build and run commands, declared platforms, internal resolution and scaling policy, UI system, safe-area handling, and supported input capabilities. Read project configuration and distribution targets before assuming that phone, desktop, or controller support is required. If the support matrix is missing, infer it from the delivery environment and state the assumption. Ask the user when choosing the wrong platform would materially change the work. For an otherwise unspecified browser game, use [device-baselines.md](references/device-baselines.md) as a provisional matrix. ## 2. Reproduce the matrix Run the game under each relevant combination of: - viewport and aspect ratio; - orientation and live resize; - pixel density, UI scale, and safe-area inset; - touch, pointer, keyboard, controller, and supported hybrid combinations; - input changes during a session, when the platform permits them. Prefer real devices or the engine's simulator. Viewport emulation proves only the conditions it actually emulates. If the game cannot run, inspect source and label every finding inferred rather than observed. ## 3. Check the experience **Layout.** Check the play area, HUD, menus, overlays, and system UI at the narrowest, widest, shortest, and tallest supported