Board Thread:Support Requests - Getting Technical/@comment-24577221-20160401170432/@comment-1807002-20160406231712

This should remove ONLY the horizontal group borders:

.pi-horizontal-group .pi-horizontal-group-item { border-left: none !important; border-right: none !important; }

I tested on a simple sample Infobox only, so if it proves to not work let me know I'll look further into it.