Shortcode Used:

[nlposts number_posts=3
         display_type=block
         css_style=columns
         sort_by_date=true sorting_limit=6
]

CSS Used:

.nlposts-block-container .nlposts-block-item {
     float:left;
     display:block;
     width:28.3%;
     margin-left: auto;
     margin-right: auto;
     margin-right: 5px;
     margin-top:10px;
     background:#efefef;
     border:1px solid #eaeaea;
     border-radius: 5px;
     -moz-border-radius: 5px; /* deprecated */
     -webkit-border-radius: 5px;
}

Results: