diff --git a/src/Controller/OverviewController.php b/src/Controller/OverviewController.php
index 14e91fa..7d7be15 100644
--- a/src/Controller/OverviewController.php
+++ b/src/Controller/OverviewController.php
@@ -30,7 +30,7 @@ class OverviewController extends ControllerBase {
    *
    * @var \Drupal\paragraphs_collection\GridLayoutDiscoveryInterface
    */
-  protected $gridDiscovery;
+  protected $gridLayoutDiscovery;
 
   /**
    * The discovery service for style files.
@@ -40,37 +40,40 @@ class OverviewController extends ControllerBase {
   protected $styleDiscovery;
 
   /**
-   * Discoverable items keyed by Paragraphs Types keyed by behavior plugins.
+   * A nested array of grid layout machine names.
    *
-   * The structure is:
-   * @code
-   * ['<plugin ID>' => ['<Paragraphs Type ID>' => <item(s) (plugin-specific)>]]
-   * @endcode
+   * The first level is keyed by Paragraphs Type IDs. The second-level keys have
+   * no meaning. The second-level values are machine names of the grid layouts
+   * that the first-level key Paragraphs Type has enabled.
+   * Exception: An empty second-level array means that all layouts are enabled
+   * for that Paragraphs Type.
    *
-   * Items:
-   *
-   * For the grid layout plugin, each Paragraphs Type has the machine names of
-   * all enabled layouts in an array. Exception: An empty array means that all
-   * layouts are enabled for that Paragraphs Type.
+   * @var array
+   */
+  protected $gridLayoutsOrderedByParagraphsTypes;
+
+  /**
+   * An array of style group machine names keyed by Paragraphs Type IDs.
    *
-   * For the style plugin, each Paragraphs Type has the machine name of the
-   * style group is uses as its value. Exception: An empty string means that all
-   * style groups are enabled for that Paragraphs Type.
+   * Each Paragraph Type has the style group is uses as the value.
+   * Exception: An empty string as the value means that all style groups are
+   * enabled for that Paragraphs Type.
    *
    * @var array
    */
-  protected $itemsPerParagraphsTypesPerPlugins;
+  protected $styleGroupsOrderedByParagraphsTypes;
+
 
   /**
    * Constructs a \Drupal\paragraphs_collection\Controller\OverviewController object.
    *
-   * @param \Drupal\paragraphs_collection\GridLayoutDiscoveryInterface $grid_discovery
+   * @param \Drupal\paragraphs_collection\GridLayoutDiscoveryInterface $grid_layout_discovery
    *   The discovery service for grid layout files.
    * @param \Drupal\paragraphs_collection\StyleDiscoveryInterface $style_discovery
    *   The discovery service for style files.
    */
-  public function __construct(GridLayoutDiscoveryInterface $grid_discovery, StyleDiscoveryInterface $style_discovery) {
-    $this->gridDiscovery = $grid_discovery;
+  public function __construct(GridLayoutDiscoveryInterface $grid_layout_discovery, StyleDiscoveryInterface $style_discovery) {
+    $this->gridLayoutDiscovery = $grid_layout_discovery;
     $this->styleDiscovery = $style_discovery;
   }
 
@@ -85,31 +88,51 @@ class OverviewController extends ControllerBase {
   }
 
   /**
-   * Lists Paragraphs Types with discoverable items they allow for a plugin.
+   * Lists Paragraphs Types with the grid layouts they allow.
    *
-   * @param string $plugin_id
-   *   The ID of the behaviour plugin that the discoverable items belong to.
-   *   Only "grid_layout" and "style" are currently supported.
+   * @return array
+   *   A nested array. The first level is keyed by Paragraphs Type IDs. The
+   *   second-level keys have no meaning. The second-level values are machine
+   *   names of the grid layouts that the first-level key Paragraphs Type has
+   *   enabled.
+   *   Exception: An empty second-level array means that all layouts are enabled
+   *   for that Paragraphs Type.
+   */
+  protected function getGridLayoutsOrderedByParagraphsTypes() {
+    if (isset($this->gridLayoutsOrderedByParagraphsTypes)) {
+      return $this->gridLayoutsOrderedByParagraphsTypes;
+    }
+
+    $paragraph_type_ids = \Drupal::entityQuery('paragraphs_type')->execute();
+    $paragraphs_types_enabled = [];
+    foreach ($paragraph_type_ids as $paragraph_type_id) {
+      /** @var ParagraphsType $paragraphs_type */
+      $paragraphs_type = ParagraphsType::load($paragraph_type_id);
+      $configuration = $paragraphs_type->getBehaviorPlugin('grid_layout')->getConfiguration();
+      if (isset($configuration['enabled']) && $configuration['enabled']) {
+        $paragraphs_types_enabled[$paragraph_type_id] = [];
+        foreach ($configuration['available_grid_layouts'] as $key => $value) {
+          if ($value) {
+            $paragraphs_types_enabled[$paragraph_type_id][] = $key;
+          }
+        }
+      }
+    }
+    return $this->gridLayoutsOrderedByParagraphsTypes = $paragraphs_types_enabled;
+  }
+
+  /**
+   * Lists Paragraphs Types with the style groups they use.
    *
    * @return array
-   *   Discoverable items keyed by by Paragraphs Type IDs. The form of the items
-   *   depends on the behaviour plugin.
-   *   For the grid layout plugin, these are arrays of grid layout machine names
-   *   keyed by the IDs of Paragraph Types which have them enabled. A Paragraphs
-   *   Type ID with an empty array as its value means that all grid layouts are
+   *   An array of style group machine names keyed by Paragraphs Type IDs. Each
+   *   Paragraph Type has the style group is uses as the value.
+   *   Exception: An empty string as the value means that all style groups are
    *   enabled for that Paragraphs Type.
-   *   For the style plugin, the items are style groups machine names keyed by
-   *   the IDs of Paragraph Types which use them. A Paragraphs Type ID with an
-   *   empty sting as its value means that all styles are enabled for that
-   *   Paragraphs Type.
-   *   For an an unsupported plugin, an empty array is returned.
-   *
-   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
-   *   If the behaviour plugin ID is invalid.
    */
-  public function getItemsPerParagraphsTypesPerPlugin($plugin_id) {
-    if (isset($this->itemsPerParagraphsTypesPerPlugins[$plugin_id])) {
-      return $this->itemsPerParagraphsTypesPerPlugins[$plugin_id];
+  protected function getStyleGroupsOrderedByParagraphsTypes() {
+    if (isset($this->styleGroupsOrderedByParagraphsTypes)) {
+      return $this->styleGroupsOrderedByParagraphsTypes;
     }
 
     $paragraph_type_ids = \Drupal::entityQuery('paragraphs_type')->execute();
@@ -117,26 +140,12 @@ class OverviewController extends ControllerBase {
     foreach ($paragraph_type_ids as $paragraph_type_id) {
       /** @var ParagraphsType $paragraphs_type */
       $paragraphs_type = ParagraphsType::load($paragraph_type_id);
-      $configuration = $paragraphs_type->getBehaviorPlugin($plugin_id)->getConfiguration();
+      $configuration = $paragraphs_type->getBehaviorPlugin('style')->getConfiguration();
       if (isset($configuration['enabled']) && $configuration['enabled']) {
-        switch ($plugin_id) {
-          case 'grid_layout':
-            $paragraphs_types_enabled[$paragraph_type_id] = [];
-            foreach ($configuration['available_grid_layouts'] as $key => $value) {
-              if ($value) {
-                $paragraphs_types_enabled[$paragraph_type_id][] = $key;
-              }
-            }
-            break;
-          case 'style':
-            $paragraphs_types_enabled[$paragraph_type_id] = $configuration['group'];
-            break;
-          default:
-            return $this->itemsPerParagraphsTypesPerPlugins[$plugin_id] = [];
-        }
+        $paragraphs_types_enabled[$paragraph_type_id] = $configuration['group'];
       }
     }
-    return $this->itemsPerParagraphsTypesPerPlugins[$plugin_id] = $paragraphs_types_enabled;
+    return $this->styleGroupsOrderedByParagraphsTypes = $paragraphs_types_enabled;
   }
 
   /**
@@ -150,7 +159,7 @@ class OverviewController extends ControllerBase {
    */
   public function getParagraphsTypesPerLayout($layout) {
     $paragraphs_types = [];
-    foreach ($this->getItemsPerParagraphsTypesPerPlugin('grid_layout') as $paragraphs_type => $enabled_layouts) {
+    foreach ($this->getGridLayoutsOrderedByParagraphsTypes() as $paragraphs_type => $enabled_layouts) {
       if ($enabled_layouts == [] || in_array($layout, $enabled_layouts)) {
         $paragraphs_types[] = $paragraphs_type;
       }
@@ -170,7 +179,7 @@ class OverviewController extends ControllerBase {
    */
   public function getParagraphsTypesPerStyle($style) {
     $paragraphs_types = [];
-    foreach ($this->getItemsPerParagraphsTypesPerPlugin('style') as $paragraphs_type => $used_style_group) {
+    foreach ($this->getStyleGroupsOrderedByParagraphsTypes() as $paragraphs_type => $used_style_group) {
       $enabled_styles = array_keys($this->styleDiscovery->getStyleOptions($used_style_group));
       if (in_array($style, $enabled_styles)) {
         $paragraphs_types[] = $paragraphs_type;
@@ -187,9 +196,101 @@ class OverviewController extends ControllerBase {
    *   The output render array.
    */
   public function layouts() {
-    return self::content('grid_layout');
+    $header = [
+      'label' => $this->t('Grid layout'),
+      'details' => $this->t('Details'),
+      'use' => $this->t('Used in'),
+    ];
+
+    $layouts = $this->gridLayoutDiscovery->getGridLayouts();
+    uasort($layouts, function ($layout1, $layout2) {
+      return strcasecmp($layout1['title'], $layout2['title']);
+    });
+
+    $rows =[];
+    foreach ($layouts as $layout_id => $layout) {
+      $paragraphs_type_ids = $this->getParagraphsTypesPerLayout($layout_id);
+
+      $paragraphs_type_link_list = [];
+      foreach ($paragraphs_type_ids as $paragraphs_type_id) {
+        $paragraphs_type = ParagraphsType::load($paragraphs_type_id);
+
+        if($paragraphs_type_link_list != []) {
+          $paragraphs_type_link_list[] = ['#plain_text' => ', '];
+        }
+
+        $paragraphs_type_link_list[] = [
+          '#type' => 'link',
+          '#title' => $paragraphs_type->label(),
+          '#url' => $paragraphs_type->toUrl(),
+          '#attributes' => [
+            'class' => ['table-filter-paragraphs-type-source'],
+          ],
+        ];
+      }
+
+      $row['label'] = [
+        '#type' => 'markup',
+        '#markup' => Html::escape($layout['title']),
+        '#prefix' => '<span class="table-filter-text-source">',
+        '#suffix' => '</span>',
+      ];
+      $row['details'] = [
+        '#type' => 'details',
+        '#title' => $this->t($layout['description']) ?: $this->t('Details'),
+        '#open' => FALSE,
+        '#attributes' => ['class' => ['overview-details']],
+      ];
+      $row['details']['id'] = [
+        '#type' => 'item',
+        '#title' => $this->t('ID'),
+        '#markup' => '<span class="table-filter-text-source">'. Html::escape($layout_id) . '</span>',
+        '#prefix' => '<div class="container-inline">',
+        '#suffix' => '</div>',
+      ];
+      $row['use'] = $paragraphs_type_link_list;
+
+      $rows[] = $row;
+    }
+
+    $table = [
+      '#type' => 'table',
+      '#header' => $header,
+      '#sticky' => TRUE,
+      '#attributes' => [
+        'class' => ['paragraphs-collection-overview-table'],
+      ],
+    ];
+    $table += $rows;
+
+    $filters = [
+      '#type' => 'fieldset',
+      '#attributes' => [
+        'class' => ['table-filter', 'js-show', 'form--inline'],
+        'data-table' => '.paragraphs-collection-overview-table',
+      ],
+      '#weight' => -10,
+      '#title' => $this->t('Filter'),
+    ];
+    $filters['text'] = [
+      '#type' => 'search',
+      '#title' => $this->t('Grid layout label or ID'),
+      '#size' => 40,
+      '#attributes' => [
+        'class' => ['table-filter-text'],
+        'autocomplete' => 'off',
+        'title' => $this->t('Enter a part of the style label or ID to filter by.'),
+      ],
+    ];
+
+    $build['table'] = $table;
+    $build['filters'] = $filters;
+    $build['#attached']['library'] = ['paragraphs_collection/overview'];
+
+    return $build;
   }
 
+
   /**
    * Generates an overview page of available styles for the styles plugin.
    *
@@ -197,66 +298,20 @@ class OverviewController extends ControllerBase {
    *   The output render array.
    */
   public function styles() {
-    return self::content('style');
-  }
-
-  /**
-   * Generates an overview page of available discoverable items for a plugin.
-   *
-   * Discoverable items are styles for the style plugin and layouts for the
-   * grid layout plugin.
-   *
-   * @param string $plugin_id
-   *   The ID of the behaviour plugin that the discoverable items belong to.
-   *   Only "grid_layout" and "style" are currently supported.
-   *
-   * @return array|null
-   *   The output render array. NULL for invalid plugin IDs and unsupported
-   *   behavior plugins.
-   */
-  public function content($plugin_id) {
-    switch ($plugin_id) {
-      case 'grid_layout':
-        $label = $this->t('Grid layout');
-        break;
-      case 'style':
-        $label = $this->t('Style');
-        break;
-      default:
-        return NULL;
-    }
     $header = [
-      'label' => $label,
+      'label' => $this->t('Style'),
       'details' => $this->t('Details'),
       'use' => $this->t('Used in'),
     ];
 
-    switch ($plugin_id) {
-      case 'grid_layout':
-        $items = $this->gridDiscovery->getGridLayouts();
-        break;
-      case 'style':
-        $items = $this->styleDiscovery->getStyles();
-        break;
-      default:
-        return NULL;
-    }
-    uasort($items, function ($item1, $item2) {
-      return strcasecmp($item1['title'], $item2['title']);
+    $styles = $this->styleDiscovery->getStyles();
+    uasort($styles, function ($style1, $style2) {
+      return strcasecmp($style1['title'], $style2['title']);
     });
 
     $rows =[];
-    foreach ($items as $item_id => $item) {
-      switch ($plugin_id) {
-        case 'grid_layout':
-          $paragraphs_type_ids = $this->getParagraphsTypesPerLayout($item_id);
-          break;
-        case 'style':
-          $paragraphs_type_ids = $this->getParagraphsTypesPerStyle($item_id);
-          break;
-        default:
-          return NULL;
-      }
+    foreach ($styles as $style_id => $style) {
+      $paragraphs_type_ids = $this->getParagraphsTypesPerStyle($style_id);
 
       $paragraphs_type_link_list = [];
       foreach ($paragraphs_type_ids as $paragraphs_type_id) {
@@ -276,49 +331,45 @@ class OverviewController extends ControllerBase {
         ];
       }
 
+      $group_list = [];
+      foreach ($style['groups'] as $group) {
+        if ($group_list != []) {
+          $group_list[] = ['#plain_text' => ', '];
+        }
+        $group_list[] = [
+          '#type' => 'markup',
+          '#markup' => Html::escape($group),
+          '#prefix' => '<span class="table-filter-group-source">',
+          '#suffix' => '</span>',
+        ];
+      }
+
       $row['label'] = [
         '#type' => 'markup',
-        '#markup' => Html::escape($item['title']),
+        '#markup' => Html::escape($style['title']),
         '#prefix' => '<span class="table-filter-text-source">',
         '#suffix' => '</span>',
       ];
       $row['details'] = [
         '#type' => 'details',
-        '#title' => $this->t($item['description']) ?: $this->t('Details'),
+        '#title' => $this->t($style['description']) ?: $this->t('Details'),
         '#open' => FALSE,
         '#attributes' => ['class' => ['overview-details']],
       ];
       $row['details']['id'] = [
         '#type' => 'item',
         '#title' => $this->t('ID'),
-        '#markup' => '<span class="table-filter-text-source">'. Html::escape($item_id) . '</span>',
+        '#markup' => '<span class="table-filter-text-source">'. Html::escape($style_id) . '</span>',
+        '#prefix' => '<div class="container-inline">',
+        '#suffix' => '</div>',
+      ];
+      $row['details']['groups'] = [
+        '#type' => 'item',
+        '#title' => $this->t('Groups'),
+        'item' => $group_list,
         '#prefix' => '<div class="container-inline">',
         '#suffix' => '</div>',
       ];
-      switch ($plugin_id) {
-        case 'style':
-          $group_list = [];
-          foreach ($item['groups'] as $group) {
-            if ($group_list != []) {
-              $group_list[] = ['#plain_text' => ', '];
-            }
-            $group_list[] = [
-              '#type' => 'markup',
-              '#markup' => Html::escape($group),
-              '#prefix' => '<span class="table-filter-group-source">',
-              '#suffix' => '</span>',
-            ];
-          }
-          $row['details']['groups'] = [
-            '#type' => 'item',
-            '#title' => $this->t('Groups'),
-            'item' => $group_list,
-            '#prefix' => '<div class="container-inline">',
-            '#suffix' => '</div>',
-          ];
-          break;
-        default:
-      }
       $row['use'] = $paragraphs_type_link_list;
 
       $rows[] = $row;
@@ -334,6 +385,10 @@ class OverviewController extends ControllerBase {
     ];
     $table += $rows;
 
+    $group_options = $this->styleDiscovery->getStyleGroups();
+    asort($group_options);
+    $empty_option = ['' => '- All -'];
+
     $filters = [
       '#type' => 'fieldset',
       '#attributes' => [
@@ -343,25 +398,17 @@ class OverviewController extends ControllerBase {
       '#weight' => -10,
       '#title' => $this->t('Filter'),
     ];
-    switch ($plugin_id) {
-      case 'style':
-        $group_options = $this->styleDiscovery->getStyleGroups();
-        asort($group_options);
-        $empty_option = ['' => '- All -'];
-
-        $filters['group'] = [
-          '#type' => 'select',
-          '#title' => $this->t('Group'),
-          '#options' => $empty_option + $group_options,
-          '#attributes' => [
-            'class' => ['table-filter-group-select'],
-          ],
-        ];
-        break;
-      default:
-    }
+    $filters['group'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Group'),
+      '#options' => $empty_option + $group_options,
+      '#attributes' => [
+        'class' => ['table-filter-group-select'],
+      ],
+    ];
     $filters['text'] = [
       '#type' => 'search',
+      '#title' => $this->t('Style label or ID'),
       '#size' => 40,
       '#attributes' => [
         'class' => ['table-filter-text'],
@@ -369,15 +416,6 @@ class OverviewController extends ControllerBase {
         'title' => $this->t('Enter a part of the style label or ID to filter by.'),
       ],
     ];
-    switch ($plugin_id) {
-      case 'grid_layout':
-        $filters['text']['#title'] = $this->t('Grid layout label or ID');
-        break;
-      case 'style':
-        $filters['text']['#title'] = $this->t('Style label or ID');
-        break;
-      default:
-    }
 
     $build['table'] = $table;
     $build['filters'] = $filters;
diff --git a/src/Tests/ParagraphsCollectionOverviewTest.php b/src/Tests/ParagraphsCollectionOverviewTest.php
new file mode 100644
index 0000000..65a2dcb
--- /dev/null
+++ b/src/Tests/ParagraphsCollectionOverviewTest.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace Drupal\paragraphs_collection\Tests;
+
+use Drupal\paragraphs\Tests\Experimental\ParagraphsExperimentalTestBase;
+
+/**
+ * Tests the Paragraphs Collection overview pages.
+ *
+ * @group paragraphs_collection
+ */
+class ParagraphsCollectionOverviewTest extends ParagraphsExperimentalTestBase {
+
+  /**
+   * Modules to be enabled.
+   *
+   * @var array
+   */
+  public static $modules = [
+    'paragraphs_collection',
+    'paragraphs_collection_demo',
+    'link',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+  }
+
+  /**
+   * Tests the overview pages of discoverable items.
+   *
+   * These are the layouts for the grid layout plugin and styles for the style
+   * plugin.
+   */
+  public function testOverviewPages() {
+    $this->loginAsAdmin([
+      'administer paragraphs types',
+      'access site reports',
+    ]);
+
+    // Check the new link on the reports page.
+    $this->drupalGet('/admin/reports');
+    $this->assertText('Overviews of items discoverable by behavior plugins.');
+    $this->clickLink('Paragraphs Collection');
+
+    // Check the grid layouts overview.
+    $this->assertUrl('/admin/reports/paragraphs_collection/layouts');
+    $this->assertTitle('Available grid layouts | Drupal');
+    $this->assertText('Grid layout label or ID');
+    $this->assertText('Details');
+    $this->assertText('Used in');
+
+    // Check that a concrete grid layout is displayed.
+    $this->assertText('Two columns');
+    $this->assertText('Defines a two column layout with 8-4 widths');
+    $this->assertText('paragraphs_two_column');
+    $this->assertLink('Grid');
+    $this->assertLinkByHref('/admin/structure/paragraphs_type/grid');
+
+    // Check the tabs.
+    $this->assertLink('Layouts');
+    $this->clickLink('Styles');
+
+    // Check the styles layouts overview.
+    $this->assertUrl('/admin/reports/paragraphs_collection/styles');
+    $this->assertTitle('Available styles | Drupal');
+    $this->assertText('Group');
+    $this->assertText('Style label or ID');
+    $this->assertText('Details');
+    $this->assertText('Used in');
+
+    // Check that a concrete style is displayed.
+    $this->assertText('Blue');
+    $this->assertText('paragraphs-blue');
+    $this->assertText('General Group');
+    $this->assertLink('Container');
+    $this->assertLinkByHref('/admin/structure/paragraphs_type/paragraphs_container');
+
+    // Check the tabs.
+    $this->assertLink('Layouts');
+    $this->assertLink('Styles');
+  }
+
+}