Non-specific CSS breaks other plugins

In includes/widgets/widget-custom-categories.php you have this code:

		<style>
		.chosen-container{
			width: 100% !important;
			margin-bottom: 10px;
		}
		.chosen-container:nth-of-type(2) {
    		display: none;
		}
		</style>

chosen.js is a popular library, at the moment because your CSS is not specific enough it’s breaking other plugins in the Customizer.

Also in admin/class-blossomthemes-toolkit-admin.php you have the incorrect handle:

wp_enqueue_script( 'select2', plugin_dir_url( __FILE__ ) . 'js/chosen.jquery.min.js', array( 'jquery' ), $this->version, true );