Isotope + Filtering with Custom Taxonomy and Custom Post Type

cpt_loop.php

<!-- PROJECTS -->
<section id="projects" class="row">
	
	<?php
		$args = array( 
			'post_type' => 'pt-project',
			'posts_per_page' => -1, 
			'orderby' => 'menu_order', // When order via "Simple Page Ordering"-Plugin
			'order' => 'ASC'
		);
		
		$loop = new WP_Query( $args );
		while ( $loop->have_posts() ) : $loop->the_post(); 
		 
		$terms = get_the_terms( $post->ID, 'kategorie' );	// Custom Taxonomy Terms
		if ( $terms && ! is_wp_error( $terms ) ) : 
		
		$links = array();
		
		foreach ( $terms as $term ) {
			$links[] = $term->name;
		}
		
		$tax_links = join( " ", str_replace(' ', '-', $links));          
		$tax = strtolower($tax_links);
		else :	
		$tax = '';					
		endif;
		
		$thumb = wp_get_attachment_image_src( get_post_thumbnail_id(), 'medium');
		$url = $thumb[0];
		$width = $thumb[1];
		$height = $thumb[2];
	?>
	        
    <article class="item project-container four <?php echo $tax; ?>">
    	<a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>" class="project-inner">
    		<div class="project-info">
    			<div class="project-info-inner">
	    			<div class="info-content">
				    	<span class="project-icon icon-<?php echo $tax; ?>"><?php echo $tax_links; ?></span>
					    <h1><?php the_title(); ?></h1>
	    			</div>
	    		</div>
		    </div>
		    <img src="<?php echo $url; ?>" width="<?php echo $width; ?>" height="<?php echo $height; ?>" />
    	</a>
    </article>
	  
	<?php endwhile;  ?>
	<?php wp_reset_query(); ?>
    
    
</section>
<!-- PROJECTS END -->

filters.php

<!-- PROJECT FILTER -->
	<div class="filters">
	    <?php
/* 		$args = array('hide_empty' => false); */
			$terms = get_terms('kategorie', $args); // Get Taxonomy Terms
	        $count = count($terms);
	            echo '<div class="filter"><a href="#filter=*" title="" class="active"><span>Alle Projekte</span></a></div>';
	        if ( $count > 0 ){
	 
	            foreach ( $terms as $term ) {
	 
	                $termname = strtolower($term->name);
	                $termname = str_replace(' ', '-', $termname);
	                echo '<div class="filter ' . $termname . '"><a href="#filter=.'.$termname.'" title="" data-filter=".'.$termname.'"><span>'.$term->name.'</span></a></div>';
	            }
	        }
	    ?>
	</div>
<!-- PROJECT FILTER END -->

isotope.css

/* Isotope Transitions
------------------------------- */
.isotope,
.isotope .item {
  -webkit-transition-duration: 0.8s;
  transition-duration: 0.8s;
}

.isotope {
  -webkit-transition-property: height, width;
  transition-property: height, width;
}

.isotope .item {
  -webkit-transition-property: -webkit-transform, opacity;
  transition-property: transform, opacity;
}
  
  
/* responsive media queries */

@media (max-width: 768px) {
  header h1 small {
    display: block;
  }

  header div.description {
    padding-top: 9px;
    padding-bottom: 4px;
  }

  .isotope .item {
    position: static ! important;
    -webkit-transform: translate(0px, 0px) ! important;
    -ms-transform: translate(0px, 0px) ! important;
    transform: translate(0px, 0px) ! important;
  }
}

jquery_isotope_functions.js

function getHashFilter() {
  var hash = location.hash;
  // get filter=filterName
  var matches = location.hash.match( /filter=([^&]+)/i );
  var hashFilter = matches && matches[1];
  return hashFilter && decodeURIComponent( hashFilter );
}

var $container = $('#projects');
		var $filters = $('.filters');
		var isIsotopeInit = false;
		var $item = $(".project-container");
		
		// bind filter button click
/*
		var $filters = $('.filters').on( 'click', 'a', function(e) {
			e.preventDefault();
			var filterAttr = $( this ).attr('data-filter');
			location.hash = 'filter=' + encodeURIComponent( filterAttr );
		});
*/
	
		
		function onHashchange() {
			var hashFilter = getHashFilter();
			if ( !hashFilter && isIsotopeInit ) {
				return;
			}
			if(!hashFilter) {
				$container.isotope({
					itemSelector: '.item',
					filter: '*'
				});
				
				$filters.find('a[href="#filter=*"]').addClass('active');
			}
			isIsotopeInit = true;
			// filter isotope
			$container.isotope({
				itemSelector: '.item',
				filter: hashFilter
			});
			
			// set selected class on button
			if ( hashFilter ) {
				$filters.find('.active').removeClass('active');
				$filters.find('a[href="#filter=' + hashFilter + '"]').addClass('active');
			}
			
			$(window).resize();
		}
		
		$(window).on( 'hashchange', onHashchange );
		
		
		$('.main').imagesLoaded().always( function( instance ) {
			onHashchange();
		});