How to show posts in grid style on search result page?

I want to show posts in a grid-style layout on the search result page when someone searches for something using the search bar. Right now it is showing a list-style layout. I also want to hide the “excerpt” and “continue reading” link. Website link – http://test123.42web.io/ . When clicking on the website link, please wait a little for the website to load up, it is a bit slow.