MobileStylePanel

The style panel as a popover, for narrow layouts.

The trigger is a palette, which is what a control that opens a panel of colours, fills and dashes is marked with everywhere else. It used to be fill-solid — a filled square, meant as a swatch of the current colour but never wired to one, so it was a black square whatever the shape was, and read as a stop button rather than as styling.

It sits in a plate of its own, docked at the right end of the row the common actions sit in — mirroring the zoom bar at the left end of the row below. Without the plate it was a button with no placement *and* no variables, so it rendered at the container's top-left corner at two thirds of its size, under the menu plate: --mocanvas-ui-btn is declared on .mocanvas-panel, and a width that reads an undefined variable is dropped.