The reactance of a capacitor is a function of capacitance and frequency, and lead or lag doesn't apply to it. The current leads the voltage across the capacitor, or, stated another way, the voltage across the capacitor lags the current through it.
What the guy above said. Complex impedences can be represented in phasor (instead of cartesian form), but the angles arent moving with time (ie. relative to the voltage and current phase angles).