diff --git a/class/init.php b/class/init.php
index 3f67ff7..0769879 100644
--- a/class/init.php
+++ b/class/init.php
@@ -151,7 +151,7 @@ class MCI_Footnotes {
             'mci-footnotes-css-public',
             plugins_url('../css/public.css', __FILE__),
             '',
-            '2.1.1d4'
+            '2.1.1d5'
         );
     }
 
diff --git a/class/task.php b/class/task.php
index 3a04954..e36beb7 100644
--- a/class/task.php
+++ b/class/task.php
@@ -5,15 +5,15 @@
  * @filesource
  * @author Stefan Herndler
  * @since 1.5.0
- * 
+ *
  * Edited for v2.0.0 and following.
- * 
+ *
  * Edited for v2.0.5: Autoload / infinite scroll support added thanks to code from
  * @docteurfitness <https://wordpress.org/support/topic/auto-load-post-compatibility-update/>
- * 
+ *
  * Edited for v2.0.9: DISABLED the_post HOOK  2020-11-08T1839+0100
  * Edited for v2.1.0: Promoted the 'Continue reading' button from localization to customization  2020-11-08T2146+0100
- * 
+ *
  * Last modified   2020-11-08T2146+0100
  */
 
@@ -60,15 +60,15 @@ class MCI_Footnotes_Task {
      *
      * @author Stefan Herndler
      * @since 1.5.0
-     * 
+     *
      * Edited for v2.0.5 through v2.0.7   2020-11-02T0330+0100..2020-11-06T1344+0100
-     * 
-     * Explicitly setting all priority to (default) "10" instead of lowest "PHP_INT_MAX", 
+     *
+     * Explicitly setting all priority to (default) "10" instead of lowest "PHP_INT_MAX",
      * especially for the_content, makes the footnotes reference container display
      * beneath the content and above other features added by other plugins.
      * Requested by users: <https://wordpress.org/support/topic/change-the-position-5/>
      * Documentation: <https://codex.wordpress.org/Plugin_API/#Hook_in_your_Filter>
-     * 
+     *
      * But this change is suspected to cause issues and needs to be assessed!
      * See <https://wordpress.org/support/topic/change-the-position-5/#post-13612697>
      */
@@ -146,12 +146,18 @@ class MCI_Footnotes_Task {
             }
             echo '}';
             ?>
-		</style>
+        </style>
 <?php
         if (MCI_Footnotes_Convert::toBool(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ALTERNATIVE))) {
             echo '<script content="text/javascript">' . "\r\n";
-            echo "\t" . 'function footnoteTooltipShow(footnoteTooltipId) { document.getElementById(footnoteTooltipId).style.display = "block"; };' . "\r\n";
-            echo "\t" . 'function footnoteTooltipHide(footnoteTooltipId) { document.getElementById(footnoteTooltipId).style.display = "none"; }' . "\r\n";
+            echo "\tfunction footnoteTooltipShow(footnoteTooltipId) {\r\n";
+            echo "\t\tdocument.getElementById(footnoteTooltipId).classList.remove('hidden');\r\n";
+            echo "\t\tdocument.getElementById(footnoteTooltipId).classList.add('shown');\r\n";
+            echo "\t}\r\n";
+            echo "\tfunction footnoteTooltipHide(footnoteTooltipId) { \r\n";
+			echo "\t\tdocument.getElementById(footnoteTooltipId).classList.remove('shown');\r\n";
+			echo "\t\tdocument.getElementById(footnoteTooltipId).classList.add('hidden');\r\n";
+			echo "\t}\r\n";
             echo "</script>\r\n";
         };
     }
@@ -421,13 +427,13 @@ class MCI_Footnotes_Task {
                     )
                 );
                 $l_str_FootnoteReplaceText = $l_obj_Template->getContent();
-                
+
                 // reset the template
                 $l_obj_Template->reload();
                 if (MCI_Footnotes_Convert::toBool(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ENABLED))) {
                     $l_int_OffsetY = intval(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_INT_FOOTNOTES_MOUSE_OVER_BOX_OFFSET_Y));
                     $l_int_OffsetX = intval(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_INT_FOOTNOTES_MOUSE_OVER_BOX_OFFSET_X));
-                    
+
                     // fill in the tooltip template  templates/public/tooltip.html
                     $l_obj_TemplateTooltip->replace(
                         array(
@@ -435,12 +441,12 @@ class MCI_Footnotes_Task {
                             "id"       => $l_str_Index,
                             "position" => MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_STR_FOOTNOTES_MOUSE_OVER_BOX_POSITION),
                             "offset-y" => !empty($l_int_OffsetY) ? $l_int_OffsetY : 0,
-                            "offset-x" => !empty($l_int_OffsetX) ? $l_int_OffsetX : 0
+                            "offset-x" => !empty($l_int_OffsetX) ? $l_int_OffsetX : 0,
                         )
                     );
-					if (!MCI_Footnotes_Convert::toBool(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ALTERNATIVE))) {
-						$l_str_FootnoteReplaceText .= $l_obj_TemplateTooltip->getContent();
-					}
+                    if (!MCI_Footnotes_Convert::toBool(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_BOOL_FOOTNOTES_MOUSE_OVER_BOX_ALTERNATIVE))) {
+                        $l_str_FootnoteReplaceText .= $l_obj_TemplateTooltip->getContent();
+                    }
                     $l_obj_TemplateTooltip->reload();
                 }
             }
@@ -507,8 +513,9 @@ class MCI_Footnotes_Task {
             $l_str_FootnoteArrowIndex  = '<span class="footnote_index_item">';
             // wrap the arrow in a @media print { display:hidden } span
             $l_str_FootnoteArrowIndex .= '<span class="footnote_index_arrow">' . $l_str_Arrow . '&#x200A;</span>';
-            // get the index; add support for legacy index placeholder:
+            // get the index:
             $l_str_FootnoteArrowIndex .= MCI_Footnotes_Convert::Index(($l_str_Index + 1),  MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_STR_FOOTNOTES_COUNTER_STYLE));
+            // keep supporting legacy index placeholder:
             $l_str_FootnoteIndex       = MCI_Footnotes_Convert::Index(($l_str_Index + 1),  MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_STR_FOOTNOTES_COUNTER_STYLE));
 
             // check if it isn't the last footnote in the array
@@ -525,19 +532,20 @@ class MCI_Footnotes_Task {
                     }
                 }
             }
-            
+
             $l_str_FootnoteArrowIndex .= '</span>';
-            
+
             // replace all placeholders in the template  templates/public/reference-container-body.html
             // The individual arrow and index placeholders are for backcompat
             $l_obj_Template->replace(
                 array(
                     "post_id"     => $l_int_PostID,
                     "id"          => MCI_Footnotes_Convert::Index($l_str_FirstFootnoteIndex, MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_STR_FOOTNOTES_COUNTER_STYLE)),
+                    "arrow-index" => $l_str_FootnoteArrowIndex,
+                    "text"        => $l_str_FootnoteText,
+                    // Legacy placeholders:
                     "arrow"       => $l_str_Arrow,
                     "index"       => $l_str_FootnoteIndex,
-                    "arrow-index" => $l_str_FootnoteArrowIndex,
-                    "text"        => $l_str_FootnoteText
                 )
             );
             // extra line breaks for page source legibility:
@@ -555,13 +563,13 @@ class MCI_Footnotes_Task {
                 "label"        => MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_STR_REFERENCE_CONTAINER_NAME),
                 "button-style" => !MCI_Footnotes_Convert::toBool(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_BOOL_REFERENCE_CONTAINER_COLLAPSE)) ? 'display: none;' : '',
                 "style"        =>  MCI_Footnotes_Convert::toBool(MCI_Footnotes_Settings::instance()->get(MCI_Footnotes_Settings::C_BOOL_REFERENCE_CONTAINER_COLLAPSE)) ? 'display: none;' : '',
-                "content"      => $l_str_Body
+                "content"      => $l_str_Body,
             )
         );
 
         // free all found footnotes if reference container will be displayed
         self::$a_arr_Footnotes = array();
-        
+
         return $l_obj_TemplateContainer->getContent();
     }
 }
diff --git a/css/public.css b/css/public.css
index d45198f..d18c9a0 100755
--- a/css/public.css
+++ b/css/public.css
@@ -4,9 +4,9 @@
  * Created-Date: 15.05.14
  * Created-Time: 16:21
  * Since: 1.0
- * Version: 2.1.1d4
+ * Version: 2.1.1d5
  *
- * Last modified: 2020-11-12T0539+0100
+ * Last modified: 2020-11-12T1846+0100
  */
  
  
@@ -67,6 +67,7 @@ templates/public/footnote-alternative.html
 .footnote_tooltip {
     display: none;
     z-index: 999;
+    cursor: auto;
     text-align: left;
     padding: 12px;
     line-height: 1.2em;
@@ -75,14 +76,40 @@ templates/public/footnote-alternative.html
     font-style: normal;
 }
 
-.footnote_relative {
-	position: relative;
+/*
+alternative tooltip implementation
+*/
+.footnote_referrer.relative {
+    position: relative;
 }
-.footnote_tooltip_alternative {
-	position: absolute;
+.footnote_tooltip.position {
+	display: unset;
+    position: absolute;
     bottom: 24px;
-    left: -50px;
-    width: 400px;
+	left: -50px;
+	width: 400px;
+}
+/*
+fade-in parameters
+*/
+.footnote_tooltip.shown {
+	visibility: visible;
+	opacity: 1;
+	transition-property: visibility opacity;
+	transition-duration: 200ms;
+	transition-timing-function: linear;
+	transition-delay: 0ms;
+}
+/*
+fade-out parameters
+*/
+.footnote_tooltip.hidden {
+	visibility: hidden;
+	opacity: 0;
+	transition-property: visibility opacity;
+	transition-duration: 200ms;
+	transition-timing-function: linear;
+	transition-delay: 400ms;
 }
 
 /*
diff --git a/css/settings.css b/css/settings.css
index 55a9800..48c9af5 100755
--- a/css/settings.css
+++ b/css/settings.css
@@ -4,9 +4,9 @@
  * Created-Date: 15.05.14
  * Created-Time: 16:21
  * Since: 1.0
- * Version: 2.1.1d4
+ * Version: 2.1.1d5
  *
- * Last modified: 2020-11-12T0539+0100
+ * Last modified: 2020-11-12T1846+0100
  */
 
 
diff --git a/footnotes.php b/footnotes.php
index 834fc74..4e2a0b9 100755
--- a/footnotes.php
+++ b/footnotes.php
@@ -4,7 +4,7 @@
     Plugin URI: https://wordpress.org/plugins/footnotes/
     Description: time to bring footnotes to your website! footnotes are known from offline publishing and everybody takes them for granted when reading a magazine.
     Author: Mark Cheret
-    Version: 2.1.1d4
+    Version: 2.1.1d5
     Author URI: http://cheret.de/plugins/footnotes-2/
     Text Domain: footnotes
     Domain Path: /languages
diff --git a/readme.txt b/readme.txt
index f124cd2..1a99cc3 100755
--- a/readme.txt
+++ b/readme.txt
@@ -80,6 +80,9 @@ Visit this swift write-up from a **footnotes** user by the name of **Southwest**
 
 == Changelog ==
 
+= 2.1.1d5 =
+- Add: UI: Tooltips: Alternative implementation: added CSS animation
+
 = 2.1.1d4 =
 - Add: UI: Tooltips: added delay (400ms) before fade-out to improve usability of links and Read-on button
 - Update: Libraries: jQuery Tools: redacted jQuery.browser function use in js/jquery.tools.min.js
diff --git a/templates/public/footnote-alternative.html b/templates/public/footnote-alternative.html
index d94aa22..d8bbb1b 100644
--- a/templates/public/footnote-alternative.html
+++ b/templates/public/footnote-alternative.html
@@ -1,15 +1,15 @@
 <span
-    class="footnote_referrer footnote_relative"
+    class="footnote_referrer relative"
 	onmouseover="footnoteTooltipShow('footnote_plugin_tooltip_text_[[post_id]]_[[id]]')"
 	onmouseout="footnoteTooltipHide('footnote_plugin_tooltip_text_[[post_id]]_[[id]]')"
-	><a><sup
-        id="footnote_plugin_tooltip_[[post_id]]_[[id]]"
-        class="footnote_plugin_tooltip_text"
-		onclick="footnote_moveToAnchor_[[post_id]]('footnote_plugin_reference_[[post_id]]_[[id]]');"
-        >[[before]][[index]][[after]]</sup
+    ><a><sup
+            id="footnote_plugin_tooltip_[[post_id]]_[[id]]"
+            class="footnote_plugin_tooltip_text"
+            onclick="footnote_moveToAnchor_[[post_id]]('footnote_plugin_reference_[[post_id]]_[[id]]');"
+            >[[before]][[index]][[after]]</sup
     ></a><span
         id="footnote_plugin_tooltip_text_[[post_id]]_[[id]]"
-        class="footnote_tooltip_alternative footnote_tooltip"
+        class="footnote_tooltip position hidden"
         onmouseout="footnoteTooltipHide('footnote_plugin_tooltip_text_[[post_id]]_[[id]]')"
         >[[text]]</span
     ></span