The desktop app is four panels in a row: folders, notes, the editor and the AI chat.
Resizing
Drag the dividers between panels. Each panel has sensible limits, so the editor always keeps room to write in.
Collapsing the chat
The panel button in the editor header collapses the chat panel away entirely and brings it back. Working with it collapsed is completely normal, the chat reopens the moment you want it.
The layout follows you
Panel sizes are part of your settings, so with sync on, the layout you arranged on one machine is waiting on the next one.
On mobile
The phone shows one screen at a time by design, with the toolbar above the keyboard standing in for the desktop toolbars. On iPad the app keeps a centered column in any orientation, so nothing needs arranging there.