What happens to the network if my node goes offline?

Nothing dramatic. The Malairte network has no central server and no single point of failure. The blockchain lives across every node simultaneously, so any one node can drop offline and the network does not notice. When your node comes back online, it simply catches up by downloading the blocks it missed, resuming from the last block it verified. That said, an always-on node helps the network more than one that comes and goes, because it is reliably available to serve peers. There is no penalty for going offline, but consistent uptime is the more valuable contribution.