Is there a way that to keep the default layout for the items in group tags?

I need to hide some content for normal users and display them only to users of a certain group. So that's why I put my fields and buttons between group tags and now the layout is really bad. I've tried adding cols and colspan attributes to the group tag but nothing helps.

<group groups="base.user_root" colspan="4" cols="4">
	<button name="create_tic_document" type="object" string="Test Doc" style="margin: 20px 20px 20px 20px;"/>
	<button name="check_and_close_for_cronjob" type="object" string="Test cronjob confirm" style="margin: 20px 20px 20px 20px;"/>
	<button name="check_and_book_closed_tasks_for_cronjob" type="object" string="Test cronjob book" style="margin: 20px 20px 20px 20px;"/>
	<button name="send_notification_to_customer" type="object" string="Send Mail to Customer" style="margin: 20px 20px 20px 20px;"/>
	<button name="fill_area_id" type="object" string="Fill task area" style="margin: 20px 20px 20px 20px;"/>
</group>

 I want my buttons to be displayed in a single line, like they were displayed without group tags.