Another Conditional Formatting question

I can't figure out the right way to do this

If cell I5=0 (or blank) Normal format
If cell I5>0 and/or >J5 Format white font on black background
If cell I5=J5 Normal format
If cell I5<J5 should never happen, so I need an error alert if this happens.

None of these will involve negative numbers.

I tried to keep it simple using =(i5>j5) but 0 is highlighted if j5 is blank, and this lets j5>i5.

I tried playing around with the formulas and couldn't get them to work. Please let me know how to do this. Thanks.