/*
Using default Bootstrap 3 classes we zero out the top and
bottom padding .panel-heading ususally needs
*/
.panel-heading.nav.navbar-default{padding-top:0px;padding-bottom:0px;}
/*
Reintroduce 20px for .panel-title when a navbar is within .panel-heading.
This can be put back to @line-height-computed; in your LESS file which
is the default in type.less */
.panel-heading.nav.navbar-default h3.panel-title{margin-top:20px;}