/* button_to wraps the sign-out button in a form: keep that form from being
   a block of its own. The button itself needs nothing — preflight already
   strips its background, border and padding — and an attribute selector
   here would outrank the padding utilities the nav menus put on it. */
form[action*="sign_out"],
form[action*="users/sign_out"] {
  display: inline;
  margin: 0;
  padding: 0;
}