Fuse comes with variety of different Theme Layouts which you can see and try them from the configuration sidebar (Click on the animated, spinning cog button from the right side of your screen). These layouts are accessible from /src/app/layouts directory and you can modify them however you like.
Each layout has its own options. Those options allow you to configure the layout elements such as Toolbar, Footer and Navbar.
Inside the /layouts directory, you will find the following structure:
Fuse has a powerful layout system which allows you to configure and use a different layout per route. Each route can have its own layout configuration meaning that it's very easy to have pages like login page where there isn't any toolbar or navbar showing, without leaving the Fuse.
You can get more information about the Fuse Config Service and its usage from Config documantation page.