Some variables for easily setting cubic-bezier timing functions. Timing functions courtesy of jquery.easie and Ceaser.
You can find a demo of these easing functions here: http://jqueryui.com/easing/
.element {
transition: left 0.2s $ease-in-quad;
}
.element {
transition: left 0.2s cubic-bezier(0.550, 0.085, 0.680, 0.530);
}