- Acme Themes
#12525
acmethemes
Keymaster

Please add the below css codes in Apperance > Customize > Additional CSs

.page article.post, .page article.page, .page .single-feat{
   border: none;
   box-shadow:none;
 }

In pro version, you will get lots of additional features on the theme including left, right, both and no sidebar as well. Please check the pro version of it as well.
http://www.acmethemes.com/themes/mercantilepro

Let us know, if you have any confusion.

Regards