The modal you just saw had some custom CSS applied:

.country_selector_modal .wordpress-country-selector-modal-body {
	padding: 50px 20px;
}

.country_selector_modal_close {
	right: -30px;
	top: -15px;
	background: #fff;
}

.country_selector_modal_flag_buttons {
	margin-top: 30px
}

.country_selector_modal_goto {
	background: transparent;

	border: 2px solid #fff;
	border-radius: 20px;
	padding: 10px;
}

.country_selector_modal_stay {
		background: transparent;

}