Brakes not working after replacing brake fluid

It's a Toyota Corolla 2005. I used an empty pressure bleeder on the reservoir at around 10-15 psi. My intention was to bleed the farthest caliper to empty the old fluid.

1. I extracted maybe 1 liter of fluid and made sure to disengage the pressure bleeder to top up the reservoir.
2. The reservoir is split into two chamber where the left chamber contains the new fluid and keeps getting extracted while the right chamber has dark fluid. The chambers are separated by a plastic wall. I got curious and let the left chamber run dry to see if the right chamber would be extracted but it didn't!
3. Because the left chamber ran dry I suspect I introduced air in the system. So I extracted maybe 300 ml on the farthest caliper(I noticed air coming out at first). I then extracted maybe 100 ml from the rest of the calipers. For the final run I bled all 4 calipers just for maybe 5 seconds and noted that clear fluid was extracted with no visible air bubbles.

When the engine is off I can pump the brake pedal a few times and it would get stiff and remain so. But once engine is on the pedal almost has no resistance. And I feel that I can easily push it down to the floor(which I avoided). I tried pumping it half way a few times but it never got stiffer. Brakes don't engage at all.

What can I do in this situation?