The model
Savings is the category that carries over
Savings works differently from the rest: it doesn't reset between cycles, it accumulates. And what you set aside stops being available to spend.

What makes it different
Every other category starts over each cycle. Savings doesn't: what you set aside last cycle is still there, and whatever you add this cycle stacks on top. It's the one number that grows over time.
Setting money aside is spending it
When you assign money to savings, that money stops being available for the rest of the cycle. It can feel strict, and it's the honest way round: if the available figure still counted what you'd set aside, you'd be about to spend the same money twice.
That said, setting aside isn't spending: on the home breakdown savings gets its own line and never counts inside «spent». It's money kept, not money gone.
And taking it back out
Saving isn't never touching it. When the moment comes you withdraw from savings and leave yourself a note about where it went.
That withdrawal doesn't create a gap and doesn't touch this cycle's categories: the app understands you spent your money on purpose, not that you lost track of it. And if you got it wrong, you can undo it.
What to use it for
It works the same whether you're putting money towards something specific or building the nameless cushion that keeps one surprise from taking the whole cycle down.