Question on auras

Just curious how the reserved mana is calcuted. If i have 100% mana reserved. Am i able to use auras that reserve x amount of mana and not a percent. Before i put on the % reserved auras.

So if i reserve 80 mana first. Can i still reserve 100% mana with other auras. Or is the 80 mana still counted as a %?

Mana is reserved from your max mana - so if you reserved 100% of your mana, you have 0 left. So you can't use anything that costs you mana.