IPython/html/static/notebook/less/menubar.less

#menubar {
  .border-box-sizing();

  .navbar {
    border-top: 1px;
    border-radius: 0px 0px @border-radius-base @border-radius-base;
    margin-bottom: 6px;
  }
  
  .navbar-toggle {
    float: left;
  }
  .navbar-collapse {
    clear: left;
  }
  
}

.nav-wrapper {
  border-bottom: 1px solid @navbar-default-border;
}

i.menu-icon {
  // add padding to account for float-right
  padding-top: 4px;
}

ul#help_menu li a{
    overflow: hidden;
    padding-right: 2.2em;
    i {
        margin-right: -1.2em;
    }
}

// Make sub menus work in BS3.
// Credit: http://www.bootply.com/86684
.dropdown-submenu{position:relative;}
.dropdown-submenu>.dropdown-menu{top:0;left:100%;margin-top:-6px;margin-left:-1px;-webkit-border-radius:0 6px 6px 6px;-moz-border-radius:0 6px 6px 6px;border-radius:0 6px 6px 6px;}
.dropdown-submenu:hover>.dropdown-menu{display:block;}
.dropdown-submenu>a:after{display:block;content:" ";float:right;width:0;height:0;border-color:transparent;border-style:solid;border-width:5px 0 5px 5px;border-left-color:#cccccc;margin-top:5px;margin-right:-10px;}
.dropdown-submenu:hover>a:after{border-left-color:#ffffff;}
.dropdown-submenu.pull-left{float:none;}.dropdown-submenu.pull-left>.dropdown-menu{left:-100%;margin-left:10px;-webkit-border-radius:6px 0 6px 6px;-moz-border-radius:6px 0 6px 6px;border-radius:6px 0 6px 6px;}