This will work :
-o-transition: all 600ms cubic-bezier(0.68, 0.2, 0.265, 1);
But not this :
-o-transition: all 600ms cubic-bezier(0.68, -0.55, 0.265, 1.55);
As I tried, If value in cubic-bezier less than 1 or more than 1, It does not work,
(P0, P1, P2, P3)
Ex : cubic-bezier(0, -0.1, 0, 0); (P1 less than 1)
Why ? + What Im missing ?
Playground : http://jsfiddle.net/c632m4yu/ (Opera only)