Task: Try to change the selection/options using only your keyboard! Detailed STR: Press tab to select the option and space to disable/enable checkbox or left/right buttons for radios
NO browser-style:browser-style:browser-style with tabindex="0" (as a workaround I tested):
Results:
Without browser style: perfect accessibile, selectable with keyboard and space changes option
With browser style: no accessibile, because not selectable
With browser style and manually set tabindex: not really accessibile, selectable, but you cannot change the value of the option