diff -u b/css/paragraphs.widget.css b/css/paragraphs.widget.css
--- b/css/paragraphs.widget.css
+++ b/css/paragraphs.widget.css
@@ -113,5 +113,5 @@
 }
 
-.is-horizontal .tabs__tab {
+.is-horizontal .paragraphs-tabs .tabs__tab {
   border-bottom: 0;
 }
diff -u b/css/paragraphs.widget.scss b/css/paragraphs.widget.scss
--- b/css/paragraphs.widget.scss
+++ b/css/paragraphs.widget.scss
@@ -124,5 +124,5 @@
 }
 
-.is-horizontal .tabs__tab {
+.is-horizontal .paragraphs-tabs .tabs__tab {
   border-bottom: 0;
 }
diff -u b/js/paragraphs.admin.js b/js/paragraphs.admin.js
--- b/js/paragraphs.admin.js
+++ b/js/paragraphs.admin.js
@@ -9,8 +9,8 @@
    */
   Drupal.behaviors.bodyTabs = {
     attach: function (context, settings) {
-      /** Set content fields to visible when tabs are created. After an action being performed, stay on the same
-       * perspective. **/
+      /** Set content fields to visible when tabs are created. After an action
+       * being performed, stay on the same perspective. **/
       if($(context).find('.layout-region-node-main').hasClass('behavior-active')) {
         $(context).find('.layout-region-node-main').removeClass('content-active');
         $(context).find('.layout-region-node-main').addClass('behavior-active');
@@ -20,7 +20,8 @@
         $('.paragraphs-behavior').show();
       }
       else {
-        /** Activate content tab visually if there is no previously activated tab. */
+        /** Activate content tab visually if there is no previously activated
+         * tab. */
         if (!($(context).find('.layout-region-node-main').hasClass('content-active')) && !($(context).find('.layout-region-node-main').hasClass('behavior-active'))) {
           $(context).find('.paragraphs-tabs').find('#content').addClass('is-active');
           $(context).find('.layout-region-node-main').addClass('content-active');