UPDATE:
I've got feedback from team that S5 Live Search module is ready for Joomla 3 only. In Joomla 4, Joomla will use Smart search.
I just created menu item + module for this smart search and add this custom css:
/*Smart search*/
label.finder {display: none;}
.awesomplete {width: 100%;}
but it looks like your server has cache enabled as I don't see the changes on frontend.
Could you help to clear all caches?