Resolved Konstra - how to create a centered, vertical Offcanvas menu and how to replace the standard search box with an icon and Full Screen Overlay Search

Hello, please for your help! It is about the following - how to create a centered, vertical Offcanvas menu and how to replace the standard search box with an icon and Full Screen Overlay Search? I see that such a search option is implemented in other topics like eSports and Themis.

Link to the working site - https://amfion.hsdev.eu/

Thanks in advance!

Dragomir