How to turn Block Extended layout in single centered column

Go to WordPress Dashboard >> Divi >> Theme Options >> Custom CSS >> add below code snippet.

.et_pb_post_extra.el_dbe_block_extended
 {
	width: 100% !important;
	margin-right: 0 !important;
}
 @media screen and (min-width: 981px) 
{
.et_pb_post_extra.el_dbe_block_extended .post-media-container, .et_pb_post_extra.el_dbe_block_extended .post-media
 {
         height: 200px!important;
   }
 }

Output: