Lead Developer
The above works if you want the entire header, but if you want to use the navigation only:
1. Customize > Layout > Primary Navigation > Enable the sticky navigation
2. Upload the navigation logo
3. Choose the navigation logo position so it’s set to Regular + Sticky
4. Disable the sticky navigation
In the next version, step 1 and 4 are no longer necessary.
Documentation: http://docs.generatepress.com/
Adding CSS: http://docs.generatepress.com/article/adding-css/
Ongoing Development: https://generatepress.com/ongoing-development