Not showing gallery in columns

Including documents works fine, but the result is not shown in columns.

The wrapper div comes with this data attribute:

{“id”:46136,”include”:”47270,47254,47253″,”exclude”:””,”attachment_pg”:false,”columns”:4,”descriptions”:true,”fancy”:true,”limit”:-1,”mime_types”:”application,video,text,audio,image”,”new_window”:false,”order”:”ASC”,”orderby”:”post__in”,”paginate”:true,”post_status”:”any”,”post_type”:”attachment”,”relation”:”AND”,”skip”:0}

But the styles of the divs holding the individual documents (.document-gallery .document-icon-row) are:

width: 100%;
padding: 0;
text-align: left;

Hence, each document is shown on its own row, as opposed to in one of four columns.

How to resolve this?