It's a problem with either the rack and pinion, or the steering gear, depending on which your vehicle utilizes.
Hard power steering means there is little to no fluid left in the system. The power steering system should be flushed and checked for leaks.
The problem is probably in the steering gear. Clogged passages in steering gear. Leaks in steering gear.
Power Steering Fluid Or Power Steering Pump
it right to the left of the power steering resevoir
Power steering.
the power steering fluid is in the cannister to the right of the oil filter and to the left of the air filter housing
Could be the power steering pump.
The power steering system works on high pressure and at idle the pump does not turn fast enough to provide full assist. It requires a higher engine rpm.
could be something with the steering or with the power steering pump.
the steering will become more difficult, and it will tend to careen slightly ether left or right.
Fill your power steering fluid. When you get low it will start to whine. Do this as quickly as possible, because replacing a power steering pump is not fun.
If it is an "S' model it does not have a power steering pump. You can tell by basically having to use a lot of force to love the steering wheel when at a standstill left or right. Si models did come with A/C and power steering.