diff --git a/css/entity_browser.entity_browser.css b/css/entity_browser.entity_browser.css
new file mode 100644
index 0000000..6c4719d
--- /dev/null
+++ b/css/entity_browser.entity_browser.css
@@ -0,0 +1,8 @@
+/**
+ * @file
+ * Styles for the overall entity browser.
+ */
+
+.layout-container {
+  margin: 0;
+}
diff --git a/css/entity_browser.iframe.css b/css/entity_browser.iframe.css
new file mode 100644
index 0000000..c74a6af
--- /dev/null
+++ b/css/entity_browser.iframe.css
@@ -0,0 +1,10 @@
+/**
+ * @file
+ * Styles for the iFrame Display Plugin.
+ */
+
+/* Remove the border on our iframe element. */
+
+.entity-browser-iframe-container iframe {
+  border: none;
+}
diff --git a/entity_browser.libraries.yml b/entity_browser.libraries.yml
index d267052..ad6df23 100644
--- a/entity_browser.libraries.yml
+++ b/entity_browser.libraries.yml
@@ -6,6 +6,12 @@ common:
     - core/underscore
     - core/drupal.dialog.ajax
 
+entity_browser:
+  version: VERSION
+  css:
+    theme:
+      css/entity_browser.entity_browser.css: {}
+
 entity_list:
   version: VERSION
   css:
@@ -14,6 +20,9 @@ entity_list:
 
 iframe:
   version: VERSION
+  css:
+    theme:
+      css/entity_browser.iframe.css: {}
   js:
     js/entity_browser.iframe.js: {}
   dependencies:
diff --git a/src/Form/EntityBrowserForm.php b/src/Form/EntityBrowserForm.php
index 8cad31b..ac290da 100644
--- a/src/Form/EntityBrowserForm.php
+++ b/src/Form/EntityBrowserForm.php
@@ -134,6 +134,8 @@ class EntityBrowserForm extends FormBase implements EntityBrowserFormInterface {
       $this->entity_browser->getDisplay()->addAjax($form);
     }
 
+    $form['#attached']['library'][] = 'entity_browser/entity_browser';
+
     return $form;
   }
 
diff --git a/src/Plugin/EntityBrowser/Display/IFrame.php b/src/Plugin/EntityBrowser/Display/IFrame.php
index 44fa1b6..3eb0c62 100644
--- a/src/Plugin/EntityBrowser/Display/IFrame.php
+++ b/src/Plugin/EntityBrowser/Display/IFrame.php
@@ -141,6 +141,11 @@ class IFrame extends DisplayBase implements DisplayRouterInterface {
     $data = $event->getData();
     return [
       '#theme_wrappers' => ['container'],
+      '#attributes' => [
+        'class' => [
+          'entity-browser-iframe-container',
+        ],
+      ],
       'link' => [
         '#type' => 'html_tag',
         '#tag' => 'a',