It sure sounds like a head gasket breech to me. How else would a large amount of coolant be lost on a daily basis? It has to go somewhere. OP reports no coolant leaks onto the ground or puddles of coolant accumulating in the engine compartment. It’s either
going out the tailpipe
into the engine oil
into the transmission fluid
Rule those three out, and you a pretty much left with a head gasket breech. The only other alternative as far as I can guess is you aren’t actually putting new coolant into the radiator, it is going someplace else. And this seems implausible.
Couple of things, it is common for this generation of civic 01-05 to need headgaskets. Also, make sure the cooling fans are turning on and off since you say it overheats when you are stopped, but cools fine when driving.
I suggest the block tester to test for exhaust in the coolant as well. This was a dead giveaway on the overheating problem my GF’s old car had.
Also SMELL in the radiator when you open the cap next. DO THIS COLD OF COURSE. Does it smell like engine exhaust the way engine oil does? Often cars with a bad head gasket have the most foul smelling coolant on earth. It is a horrid smell.