Timing functions for CSS animations and transitions

_easing.scss

// _easing.scss, CSS easing functions - gist.github.com/terkel/4377409
// Based on Caesar - matthewlein.com/ceaser

$linear:            cubic-bezier( 0.250,  0.250,  0.750,  0.750 );
$ease:              cubic-bezier( 0.250,  0.100,  0.250,  1.000 );
$ease-in:           cubic-bezier( 0.420,  0.000,  1.000,  1.000 );
$ease-out:          cubic-bezier( 0.000,  0.000,  0.580,  1.000 );
$ease-in-out:       cubic-bezier( 0.420,  0.000,  0.580,  1.000 );

$ease-in-quad:      cubic-bezier( 0.550,  0.085,  0.680,  0.530 );
$ease-in-cubic:     cubic-bezier( 0.550,  0.055,  0.675,  0.190 );
$ease-in-quart:     cubic-bezier( 0.895,  0.030,  0.685,  0.220 );
$ease-in-quint:     cubic-bezier( 0.755,  0.050,  0.855,  0.060 );
$ease-in-sine:      cubic-bezier( 0.470,  0.000,  0.745,  0.715 );
$ease-in-expo:      cubic-bezier( 0.950,  0.050,  0.795,  0.035 );
$ease-in-circ:      cubic-bezier( 0.600,  0.040,  0.980,  0.335 );
$ease-in-back:      cubic-bezier( 0.600, -0.280,  0.735,  0.045 );

$ease-out-quad:     cubic-bezier( 0.250,  0.460,  0.450,  0.940 );
$ease-out-cubic:    cubic-bezier( 0.215,  0.610,  0.355,  1.000 );
$ease-out-quart:    cubic-bezier( 0.165,  0.840,  0.440,  1.000 );
$ease-out-quint:    cubic-bezier( 0.230,  1.000,  0.320,  1.000 );
$ease-out-sine:     cubic-bezier( 0.390,  0.575,  0.565,  1.000 );
$ease-out-expo:     cubic-bezier( 0.190,  1.000,  0.220,  1.000 );
$ease-out-circ:     cubic-bezier( 0.075,  0.820,  0.165,  1.000 );
$ease-out-back:     cubic-bezier( 0.175,  0.885,  0.320,  1.275 );

$ease-in-out-quad:  cubic-bezier( 0.455,  0.030,  0.515,  0.955 );
$ease-in-out-cubic: cubic-bezier( 0.645,  0.045,  0.355,  1.000 );
$ease-in-out-quart: cubic-bezier( 0.770,  0.000,  0.175,  1.000 );
$ease-in-out-quint: cubic-bezier( 0.860,  0.000,  0.070,  1.000 );
$ease-in-out-sine:  cubic-bezier( 0.445,  0.050,  0.550,  0.950 );
$ease-in-out-expo:  cubic-bezier( 1.000,  0.000,  0.000,  1.000 );
$ease-in-out-circ:  cubic-bezier( 0.785,  0.135,  0.150,  0.860 );
$ease-in-out-back:  cubic-bezier( 0.680, -0.550,  0.265,  1.550 );