By default (bug?) webflow removes padding from columns that live inside another column.

This is due to webflow css (line 10):

.w-col .w-col{
 padding-left: 0px;
 padding-right: 0px;
}

Include ‘http://outboxed-dev.net/scripts/webflow/column-fix.js’ to your project, define your own paddings within any class (even responsive ones) and let this javascript do the trick.