Post Apocalypic YA novel (possibly series) where the main characters town gets taken over by raiders

[Cade]

I read this book 3-5 years ago. What I remember: It’s far past World War 3, humanity has been separated into different survival towns. The main character lives in a town. It’s a relatively large town, and they use zip lines to traverse through it. At the main characters school, they talk about what it was like pre world war 3. The main plot begins when their camp gets raided. The raiders hold the whole town hostage. It’s up to the main character to save them. I think I remember something about the main character fighting the big bad in snow near a cliff… and the main character falls and does a series of rolls surviving, but getting injured.

[Rainbowheart]

Do you remember if the main character is male or female?