/* this is an unknown at-rule. Because we don't know what the heck
   it contains, we are going to do VERY LITTLE crunching. Whitespace
   will be reduced to a single space -- but not eliminated
   (except AFTER opening and closing braces). But before braces
   or extra semicolons -- not removed because we just don't know
   what's going on */

/* this one contains another at-rule, and a regular rule */
@three-dee 
{
  /* this one contains a declaration block */
  @background-lighting 
  {
    azimuth: 30deg;
    elevation: 190deg;
  }
  H1 { color: red }
}

/* this one is just a declaration block */
@background-lighting bright 
{
  azimuth: 30deg;
  elevation: 190deg;
}

/* this one just contains a rule block */
@whoknows foo, bar :active, ack
{
  a:link
  {
    text-decoration: underline;
  }
  body 
  {
    color: #fff;
  }
}

/* this one just has a few identifiers before the semicolon */
@anotherone foo, bar;

/* way minimum one */
@foobar;

/* a non-sense vendor-specific at-rule */
@-moz-something url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAIAAAD91JpzAAAABnRSTlMAAAAAAABupgeRAAAABmJLR0QA%2FwD%2FAP%2BgvaeTAAAAEUlEQVR42mP4%2F58BCv7%2FZwAAHfAD%2FabwPj4AAAAASUVORK5CYII%3D)
{
    1 { foobar: 20hz; }
    2 { whack: a-mole; scooby: doo; }
}

/* a vendor-specific at-rule (Safari animation) */
@-webkit-keyframes bounce {
 from {
   left: 0px;
 }
 to {
   left: 200px;
 }
}