Hi Tristan,
Thanks for reaching out! Unfortunately I think this will be a bit more difficult than it may seem if you are wanting to hide the “previous event” link on an event based on whether or not the event before it has passed or not. There isn’t any CSS I can give you to target the link based on the previous event.
If you’d like to do it with a customization, our themer’s guide is the place to start! We’re not able to do customizations for you, but if you get stuck or have any questions, please let me know! I’ll be happy to point you in the right direction.
Your best bet (and simplest solution) may be to remove the previous event link entirely, regardless of whether or not the previous event has passed. I’m sorry I don’t have a better answer for you, but I hope this helps!
Thanks,
Jennifer