For the visual elements, you will need to ask the style developer, as that is custom coding and no one would now the CSS classes used. Or you can inspect the elements with the dev tool in your browser, and see what CSS elements they are using.
For the search, I suppose you could modify this mod,
https://vborg.vbsupport.ru/showthread.php?t=226749 and read the part that starts with,
Here is the search option like vbulletin.org
But you would probably have to know some HTML as well as some CSS to get it right.