On many Linux desktops, especially those using GNOME/Wayland (such as Fedora), the mouse cursor is drawn by the compositor, not the window manager. In Chromium/Chrome on Wayland, there are (still) cases where CSS cursor: none on an element is ignored or overridden by the compositor. The Ladder Diagram uses cursor: none to remove the cursor from the Ladder Diagram canvas. So even though our code is correct, Chromium/Chrome is ignoring it!