Style control buttons have one rounded corner when focused

[foundryspatial-duncan]

The built-in mapbox-gl styles apply a border-radius to the first and last buttons in a control group:

.mapboxgl-ctrl-group button:focus:first-child {...}
.mapboxgl-ctrl-group button:focus:last-child {...}

The style control's buttons are displayed horizontally so the top/bottom edge border radius doesn't apply here. (It's more visible if you change the -active color to something darker:

Here it is in the docs' excample:

Solution is to just override those styles. Here's what I did:

// scss
.mapbox-control-styles button {
    &, &:focus {
        border-radius: 0;
    }
}