Cubic bezier presets and variables

_easings.scss

$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_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_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_BACK: cubic-bezier(0.600, -0.280, 0.735, 0.045);
$EASE_OUT_BACK: cubic-bezier(0.175, 0.885, 0.320, 1.275);
$EASE_IN_OUT_BACK: cubic-bezier(0.680, -0.550, 0.265, 1.550);