The lighting system is very easy to understand for TTRPG and how different races cope/handle it. Of course it would be way to long to put those rules here so better to just either read up on D&D (be it 2nd ed, 3 ed, 3.5 ed, 4th ed, 5th ed or even Pathfinder 1e and 2e books). Now I understand that putting 5e TT into a PC game is virtually impossible but still how light works/races see/magic help seing etc is something that really should be simple to implement (Roll20 does a very good job at how light/seeing works).
