Can't set input widths using the grid classes per bootstrap documentation when using the horizontal-form class. As form-control class sets width to 100%, this overrides any grid class widths. Bootstrap documentation shows the need to wrap the input in a div. That way we can leave form-control at 100%. And I guess(?) allow a form def option to specify the class for this div, ie col-md-6. Can't set width to auto as that just brings up the need to reinvent the grid classes to apply to the input otherwise.