$placements: "top", "bottom", "left", "right";
$origins: bottom, top, right, left;
$backdrop-origins: 0% 100%, 0 -100%, 100% 0%, -100% 0%;
$backdrop-border-radii: 40% 40% 0 0, 0 0 30% 30%, 30% 0 0 30%, 0 30% 30% 0;