diff --git a/lib/flippable.html b/lib/flippable.html
index add8b31..a4ec6a7 100644
--- a/lib/flippable.html
+++ b/lib/flippable.html
@@ -1,35 +1,43 @@
-<!doctype html>
+<!DOCTYPE html>
 <html lang="en">
-<head>
-	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
-	<title>Flippable Doctest</title>
-	<link rel="stylesheet" href="./3rdparty/highlight/styles/default.css">
-	<link rel="stylesheet" href="../css/doctest.css">
-	<script src="./3rdparty/highlight/highlight.pack.js"></script>
-    <script src="../dist/iwmlib.3rdparty.js"></script>
-	<script src="../dist/iwmlib.js"></script>
+    <head>
+        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+        <title>Flippable Doctest</title>
+        <link rel="stylesheet" href="./3rdparty/highlight/styles/default.css" />
+        <link rel="stylesheet" href="../css/doctest.css" />
+        <script src="./3rdparty/highlight/highlight.pack.js"></script>
+        <script src="../dist/iwmlib.3rdparty.js"></script>
+        <script src="../dist/iwmlib.js"></script>
 
-    <link rel="stylesheet" href="../css/flipeffect.css">
-	<template id="flipTemplate">
-        <div class="flipWrapper">
-            <div class="flipCard">
-                <div class="flipFace front"></div>
-                <div class="flipFace back" style="visibility:hidden;"></div>
-            </div>
+        <link rel="stylesheet" href="../css/flipeffect.css" />
+        <template id="flipTemplate">
+            <div class="flipWrapper">
+                <div class="flipCard">
+                    <div class="flipFace front"></div>
+                    <div class="flipFace back" style="visibility: hidden"></div>
+                </div>
                 <!-- Very tricky problem to scale svgs: see https://css-tricks.com/scale-svg/ -->
-            <svg class="flipButton backBtn" style="visibility:hidden;" viewBox="0 0 100 100" preserveAspectRatio="xMidYMid meet">
-                <g stroke-width="8" stroke="white">
-                    <circle  cx="50" cy="50" r="44" fill="gray" />
-                    <line x1="30" y1="30" x2="70" y2="70"  />
-                    <line x1="30" y1="70" x2="70" y2="30"  />
-                </g>
-            </svg>
+                <!-- SVG viewPort interferes with DOMMatrix calculations: see  
+                    https://stackoverflow.com/questions/70696387/how-to-get-transform-matrix-of-a-dom-element-->
+            <div class="flipButton backBtn" style="visibility:hidden;">
+                <svg viewBox="0 0 100 100" preserveAspectRatio="xMidYMid meet" style="width:inherit; height:inherit;">
+                    <g stroke-width="8" stroke="white">
+                        <circle  cx="50" cy="50" r="44" fill="gray" />
+                        <line x1="30" y1="30" x2="70" y2="70"  />
+                        <line x1="30" y1="70" x2="70" y2="30"  />
+                    </g>
+                </svg>
+            </div>
+            
 
-            <svg class="flipButton infoBtn" viewBox="0 0 100 100" preserveAspectRatio="xMidYMid meet">
-                <circle cx="50" cy="50" r="44" stroke="white" stroke-width="8" fill="gray" />
-                <circle cx="50" cy="32" r="7" fill="white" />
-                <line x1="50" y1="46" x2="50" y2="78" stroke="white" stroke-width="12" />
-            </svg>
+            <div class="flipButton infoBtn">
+                <svg  viewBox="0 0 100 100" preserveAspectRatio="xMidYMid meet"  style="width:inherit; height:inherit;">
+                    <circle cx="50" cy="50" r="44" stroke="white" stroke-width="8" fill="gray" />
+                    <circle cx="50" cy="32" r="7" fill="white" />
+                    <line x1="50" y1="46" x2="50" y2="78" stroke="white" stroke-width="12" />
+                </svg>
+            </div>
+            
         </div>
     </template>
 
@@ -46,6 +54,10 @@ via a HTML template that defines the placeholders for front and back views. The
 style file "css/flipeffect.css" holds reasonable default styles for this kind of
 templates.
 </p>
+<p>
+The SVG buttons have to be wrapped in an HTML DOM element which handles events. Otherwise, 
+the viewbox of the SVG will interfere with the coordinate transformation.
+</p>
 <pre><code>
     &lt;template id="flipTemplate"&gt;
         &lt;div class="flipWrapper"&gt;
@@ -59,27 +71,24 @@ templates.
     &lt;/template&gt;
 </code>
 </pre>
-<h3>
-	Example
-</h3>
-<main id="main" style="border: 1px solid gray; position: relative; height: 256px;" >
-
-</main>
-<script class="doctest">
-let scatterContainer = new DOMScatterContainer(main, {stopEvents: false})
-if (Capabilities.supportsTemplate()) {
-
-    let flip = new DOMFlip(scatterContainer,
-                            flipTemplate,
-                            new ImageLoader('./examples/king.jpeg'),
-                            new ImageLoader('./examples/women.jpeg'),
-                            { tapDelegateFactory: CardWrapper, preloadBack: true})
-    flip.load().then((flip) => {
-        flip.centerAt({ x: 150, y: 120})
-    })
-}
-else {
-    alert("Templates not supported, use Edge, Chrome, Safari or Firefox.")
-}
-</script>
-</body>
+        <h3>Example</h3>
+        <main id="main" style="border: 1px solid gray; position: relative; height: 256px"></main>
+        <script class="doctest">
+            let scatterContainer = new DOMScatterContainer(main, { stopEvents: false })
+            if (Capabilities.supportsTemplate()) {
+                let flip = new DOMFlip(
+                    scatterContainer,
+                    flipTemplate,
+                    new ImageLoader('./examples/king.jpeg'),
+                    new ImageLoader('./examples/women.jpeg'),
+                    { tapDelegateFactory: CardWrapper, preloadBack: true }
+                )
+                flip.load().then((flip) => {
+                    flip.centerAt({ x: 150, y: 120 })
+                })
+            } else {
+                alert('Templates not supported, use Edge, Chrome, Safari or Firefox.')
+            }
+        </script>
+    </body>
+</html>
