text: .selectize-dropdown.plugin-optgroup_columns {
  	.optgroup {
  		border-right: 1px solid #f2f2f2;
  		border-top: 0 none;
  		float: left;
  		.selectize-box-sizing(border-box);
  	}
  	.optgroup:last-child {
  		border-right: 0 none;
  	}
  	.optgroup:before {
  		display: none;
  	}
  	.optgroup-header {
  		border-top: 0 none;
  	}
  }
  