use class="hidden" not style="display:none"

21 files changed, 147 insertions, 153 deletions

diff --git a/files/de/web/api/canvasrenderingcontext2d/fillrect/index.html b/files/de/web/api/canvasrenderingcontext2d/fillrect/index.html
index 178a861f4e..41b31f1b6d 100644
--- a/files/de/web/api/canvasrenderingcontext2d/fillrect/index.html
+++ b/files/de/web/api/canvasrenderingcontext2d/fillrect/index.html
@@ -57,7 +57,7 @@ ctx.fillRect(10, 10, 100, 100);
 
 <p>Ändern Sie den unten gezeigten Code und sehen Sie Ihre Änderungen live im Canvas-Element:</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h6 id="Playable_code">Playable code</h6>
 
 <pre class="brush: html">&lt;canvas id="canvas" width="400" height="200" class="playable-canvas"&gt;&lt;/canvas&gt;
diff --git a/files/de/web/api/canvasrenderingcontext2d/ispointinpath/index.html b/files/de/web/api/canvasrenderingcontext2d/ispointinpath/index.html
index 5eac7321fe..ce3c4161be 100644
--- a/files/de/web/api/canvasrenderingcontext2d/ispointinpath/index.html
+++ b/files/de/web/api/canvasrenderingcontext2d/ispointinpath/index.html
@@ -65,7 +65,7 @@ console.log(ctx.isPointInPath(10, 10)); // true
 
 <p>Editieren Sie den folgenden Quelltext. Die Änderungen werden in Echtzeit übernommen und Log-Ausgaben in die <a href="/en-US/docs/Tools/Browser_Console">console</a> ausgegeben:</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h6 id="Playable_code">Playable code</h6>
 
 <pre class="brush: html">&lt;canvas id="canvas" width="400" height="200" class="playable-canvas"&gt;&lt;/canvas&gt;
diff --git a/files/de/web/api/canvasrenderingcontext2d/scale/index.html b/files/de/web/api/canvasrenderingcontext2d/scale/index.html
index b26824a51e..c6419d989f 100644
--- a/files/de/web/api/canvasrenderingcontext2d/scale/index.html
+++ b/files/de/web/api/canvasrenderingcontext2d/scale/index.html
@@ -54,7 +54,7 @@ ctx.setTransform(1, 0, 0, 1, 0, 0);
 
 <p>Editieren Sie den folgenden Code und sehen Sie die Änderungen sofort im Canvas:</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h6 id="Playable_code">Playable code</h6>
 
 <pre class="brush: html">&lt;canvas id="canvas" width="400" height="200" class="playable-canvas"&gt;&lt;/canvas&gt;
@@ -100,7 +100,7 @@ window.addEventListener("load", drawCanvas);
 
 <p>Sie können <code>ctx.scale(-1, 1)</code> benutzen, um den Inhalt horizontal zu spiegeln und <code>ctx.scale(1, -1)</code>, um ihn vertikal zu spiegeln.</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h6 id="Playable_code2">Playable code2</h6>
 
 <pre class="brush: html">&lt;canvas id="canvas" width="400" height="200" class="playable-canvas"&gt;&lt;/canvas&gt;
diff --git a/files/de/web/api/canvasrenderingcontext2d/setlinedash/index.html b/files/de/web/api/canvasrenderingcontext2d/setlinedash/index.html
index a7d5bd82c3..38aadbbfe3 100644
--- a/files/de/web/api/canvasrenderingcontext2d/setlinedash/index.html
+++ b/files/de/web/api/canvasrenderingcontext2d/setlinedash/index.html
@@ -45,7 +45,7 @@ ctx.stroke();
 
 <p>Edit the code below and see your changes update live in the canvas:</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h6 id="Playable_code">Playable code</h6>
 
 <pre class="brush: html">&lt;canvas id="canvas" width="400" height="200" class="playable-canvas"&gt;&lt;/canvas&gt;
diff --git a/files/de/web/api/document/adoptnode/index.html b/files/de/web/api/document/adoptnode/index.html
index c996e689c5..cc03e5c9e8 100644
--- a/files/de/web/api/document/adoptnode/index.html
+++ b/files/de/web/api/document/adoptnode/index.html
@@ -17,8 +17,8 @@ translation_of: Web/API/Document/adoptNode
 </pre>
 
 <dl>
- <dt><code><span style="display: none;"> </span><span style="display: none;"> </span><span style="display: none;"> </span>knoten</code></dt>
- <dd>Ist der übertragene Knoten, welcher nun dieses Dokument als sein <code><a href="/en-US/docs/DOM/Node.ownerDocument" title="DOM/Node.ownerDocument">ownerDocument</a> </code>hat.  Der Elternknoten (<code><a href="/en-US/docs/DOM/Node.parentNode">parentNode</a></code>) is <code>null</code>, da er noch nicht in den Dokumentenbaum eingefügt wurde. Zu beachten ist, dass <code>knoten</code> und <code>externerKnoten</code> nach dem Funktionsaufruf das gleiche Objekt sind.<span style="display: none;"> </span><span style="display: none;"> </span><span style="display: none;"> </span></dd>
+ <dt><code><span class="hidden"> </span><span class="hidden"> </span><span class="hidden"> </span>knoten</code></dt>
+ <dd>Ist der übertragene Knoten, welcher nun dieses Dokument als sein <code><a href="/en-US/docs/DOM/Node.ownerDocument" title="DOM/Node.ownerDocument">ownerDocument</a> </code>hat.  Der Elternknoten (<code><a href="/en-US/docs/DOM/Node.parentNode">parentNode</a></code>) is <code>null</code>, da er noch nicht in den Dokumentenbaum eingefügt wurde. Zu beachten ist, dass <code>knoten</code> und <code>externerKnoten</code> nach dem Funktionsaufruf das gleiche Objekt sind.<span class="hidden"> </span><span class="hidden"> </span><span class="hidden"> </span></dd>
  <dt><code>externerKnoten</code></dt>
  <dd>Ist der Knoten eines anderes Dokumentes, der übertragen werden soll.</dd>
 </dl>
diff --git a/files/de/web/api/event/event/index.html b/files/de/web/api/event/event/index.html
index ee30a2064c..3c78dc8a3e 100644
--- a/files/de/web/api/event/event/index.html
+++ b/files/de/web/api/event/event/index.html
@@ -24,7 +24,7 @@ translation_of: Web/API/Event/Event
  <ul>
   <li><code>"bubbles"</code>: (Optional) Ein {{jsxref("Boolean")}}, welcher angibt, ob das Event gebubbled werden soll. Der Standardwert ist <code>false</code>.</li>
   <li><code>"cancelable"</code>: (Optional) Ein {{jsxref("Boolean")}}, welcher angibt, ob das Event abgebrochen werden kann. Der Standardwert <code>false</code>.</li>
-  <li><code>"composed"</code>: (Optional) Ein {{jsxref("Boolean")}}, welcher angibt, ob das Event auch außerhalb eines Shadow-Root-Elements empfangen werden kann. Der Standardwert ist <code>false</code>.<span style="display: none;"> </span></li>
+  <li><code>"composed"</code>: (Optional) Ein {{jsxref("Boolean")}}, welcher angibt, ob das Event auch außerhalb eines Shadow-Root-Elements empfangen werden kann. Der Standardwert ist <code>false</code>.<span class="hidden"> </span></li>
  </ul>
  </dd>
 </dl>
diff --git a/files/de/web/api/keyboardevent/keycode/index.html b/files/de/web/api/keyboardevent/keycode/index.html
index 98375fe4b9..01d2a859cc 100644
--- a/files/de/web/api/keyboardevent/keycode/index.html
+++ b/files/de/web/api/keyboardevent/keycode/index.html
@@ -363,7 +363,7 @@ translation_of: Web/API/KeyboardEvent/keyCode
    <th scope="row"><code>"KeyD"</code></th>
    <td colspan="3" rowspan="1"><code>0x44 (68)</code></td>
    <td colspan="3" rowspan="1"><code>0x44 (68)</code></td>
-   <td colspan="3" rowspan="1"><code>0x44 (68)<span style="display: none;"> </span></code></td>
+   <td colspan="3" rowspan="1"><code>0x44 (68)<span class="hidden"> </span></code></td>
    <td colspan="3" rowspan="1"><code>0x44 (68)</code></td>
    <td colspan="3" rowspan="1"><code>0x44 (68)</code></td>
    <td colspan="3" rowspan="1"><code>0x44 (68)</code></td>
diff --git a/files/de/web/css/all/index.html b/files/de/web/css/all/index.html
index 5e2b7191e8..80de31880c 100644
--- a/files/de/web/css/all/index.html
+++ b/files/de/web/css/all/index.html
@@ -64,9 +64,8 @@ blockquote {
 <div id="Beispiel0" style="display: inline-block; width: 225px; vertical-align: top;">
 <h4 id="Keine_all_Eigenschaft">Keine <code>all</code> Eigenschaft</h4>
 
-<pre class="brush: html" style="display: none;">&lt;blockquote id="quote"&gt;Lorem ipsum dolor sit amet, consectetur adipiscing elit.&lt;/blockquote&gt; Phasellus eget velit sagittis.</pre>
 
-<pre class="brush: css" style="display: none;">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
+<pre class="brush: css" class="hidden">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
 blockquote { background-color: skyblue;  color: red; }</pre>
 {{EmbedLiveSample("Beispiel0", "200", "125")}}
 
@@ -76,9 +75,8 @@ blockquote { background-color: skyblue;  color: red; }</pre>
 <div id="Beispiel1" style="display: inline-block; width: 225px; vertical-align: top;">
 <h4 id="allunset"><code>all:unset</code></h4>
 
-<pre class="brush: html" style="display: none;">&lt;blockquote id="quote"&gt;Lorem ipsum dolor sit amet, consectetur adipiscing elit.&lt;/blockquote&gt; Phasellus eget velit sagittis.</pre>
 
-<pre class="brush: css" style="display: none;">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
+<pre class="brush: css" class="hidden">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
 blockquote { background-color: skyblue;  color: red; }
 blockquote { all: unset; }</pre>
 {{EmbedLiveSample("Beispiel1", "200", "125")}}
@@ -89,9 +87,8 @@ blockquote { all: unset; }</pre>
 <div id="Beispiel2" style="display: inline-block; width: 225px; vertical-align: top;">
 <h4 id="allinitial"><code>all:initial</code></h4>
 
-<pre class="brush: html" style="display: none;">&lt;blockquote id="quote"&gt;Lorem ipsum dolor sit amet, consectetur adipiscing elit.&lt;/blockquote&gt; Phasellus eget velit sagittis.</pre>
 
-<pre class="brush: css" style="display: none;">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
+<pre class="brush: css" class="hidden">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
 blockquote { background-color: skyblue;  color: red; }
 blockquote { all: initial; }</pre>
 {{EmbedLiveSample("Beispiel2", "200", "125")}}
@@ -102,9 +99,8 @@ blockquote { all: initial; }</pre>
 <div id="Beispiel3" style="display: inline-block; width: 225px; vertical-align: top;">
 <h4 id="allinherit"><code>all:inherit</code></h4>
 
-<pre class="brush: html" style="display: none;">&lt;blockquote id="quote"&gt;Lorem ipsum dolor sit amet, consectetur adipiscing elit.&lt;/blockquote&gt; Phasellus eget velit sagittis.</pre>
 
-<pre class="brush: css" style="display: none;">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
+<pre class="brush: css" class="hidden">html { font-size: small; background-color: <span class="st">#F0F0F0</span>; color:blue; }
 blockquote { background-color: skyblue; color: red; }
 blockquote { all: inherit; }</pre>
 {{EmbedLiveSample("Beispiel3", "200", "125")}}
diff --git a/files/de/web/css/animation-fill-mode/index.html b/files/de/web/css/animation-fill-mode/index.html
index adfb23a43a..c4074a5655 100644
--- a/files/de/web/css/animation-fill-mode/index.html
+++ b/files/de/web/css/animation-fill-mode/index.html
@@ -104,7 +104,7 @@ animation-fill-mode: both, forwards, none
  </table>
  </dd>
  <dt><code>both</code></dt>
- <dd>Vereint die Werte <span id="cke_bm_70S" style="display: none;"> </span><code>backwards</code><span id="cke_bm_70E" style="display: none;"> </span> und <code>forwards</code>.</dd>
+ <dd>Vereint die Werte <span id="cke_bm_70S" class="hidden"> </span><code>backwards</code><span id="cke_bm_70E" class="hidden"> </span> und <code>forwards</code>.</dd>
 </dl>
 
 <h2 id="Beispiele">Beispiele</h2>
diff --git a/files/de/web/css/appearance/index.html b/files/de/web/css/appearance/index.html
index 12a67f3f60..62ee89682e 100644
--- a/files/de/web/css/appearance/index.html
+++ b/files/de/web/css/appearance/index.html
@@ -50,7 +50,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>none</code></td>
    <td>
-    <div id="sampleNone" style="display: none;">
+    <div id="sampleNone" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: none; -webkit-appearance: none; color: black;}</pre>
 
@@ -64,7 +64,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>button</code></td>
    <td>
-    <div id="sampleButton" style="display: none;">
+    <div id="sampleButton" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: button; -webkit-appearance: button; color: black; }</pre>
 
@@ -77,7 +77,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>button-arrow-down</code></td>
    <td>
-    <div id="sampleButtonArrowDown" style="display: none;">
+    <div id="sampleButtonArrowDown" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: button-arrow-down; -webkit-appearance: button-arrow-down; color: black; }</pre>
 
@@ -90,7 +90,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>button-arrow-next</code></td>
    <td>
-    <div id="sampleButtonArrowNext" style="display: none;">
+    <div id="sampleButtonArrowNext" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: button-arrow-next; -webkit-appearance: button-arrow-next; color: black; }</pre>
 
@@ -103,7 +103,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>button-arrow-previous</code></td>
    <td>
-    <div id="sampleButtonArrowPrevious" style="display: none;">
+    <div id="sampleButtonArrowPrevious" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: button-arrow-previous; -webkit-appearance: button-arrow-previous; color: black; }</pre>
 
@@ -116,7 +116,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>button-arrow-up</code></td>
    <td>
-    <div id="sampleButtonArrowUp" style="display: none;">
+    <div id="sampleButtonArrowUp" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: button-arrow-up; -webkit-appearance: button-arrow-up; color: black; }</pre>
 
@@ -129,7 +129,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>button-bevel</code></td>
    <td>
-    <div id="sampleButtonBevel" style="display: none;">
+    <div id="sampleButtonBevel" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: button-bevel; -webkit-appearance: button-bevel; color: black; }</pre>
 
@@ -142,7 +142,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>button-focus</code></td>
    <td>
-    <div id="sampleButtonFocus" style="display: none;">
+    <div id="sampleButtonFocus" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: button-focus; -webkit-appearance: button-focus; color: black; }</pre>
 
@@ -155,7 +155,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>caret</code></td>
    <td>
-    <div id="sampleCaret" style="display: none;">
+    <div id="sampleCaret" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: caret; -webkit-appearance: caret; color: black; }</pre>
 
@@ -168,7 +168,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>checkbox</code></td>
    <td>
-    <div id="sampleCheckbox" style="display: none;">
+    <div id="sampleCheckbox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: checkbox; -webkit-appearance: checkbox; color: black; }</pre>
 
@@ -181,7 +181,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>checkbox-container</code></td>
    <td>
-    <div id="sampleCheckboxContainer" style="display: none;">
+    <div id="sampleCheckboxContainer" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: checkbox-container; -webkit-appearance: checkbox-container; color: black; }</pre>
 
@@ -194,7 +194,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>checkbox-label</code></td>
    <td>
-    <div id="sampleCheckboxLabel" style="display: none;">
+    <div id="sampleCheckboxLabel" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: checkbox-label; -webkit-appearance: checkbox-label; color: black; }</pre>
 
@@ -207,7 +207,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>checkmenuitem</code></td>
    <td>
-    <div id="sampleCheckmenuitem" style="display: none;">
+    <div id="sampleCheckmenuitem" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: checkmenuitem; -webkit-appearance: checkmenuitem; height: 20px; color: black; }</pre>
 
@@ -220,7 +220,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>dualbutton</code></td>
    <td>
-    <div id="sampleDualButton" style="display: none;">
+    <div id="sampleDualButton" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: dualbutton; -webkit-appearance: dualbutton; color: black; }</pre>
 
@@ -233,7 +233,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>groupbox</code></td>
    <td>
-    <div id="sampleGroupbox" style="display: none;">
+    <div id="sampleGroupbox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: groupbox; -webkit-appearance: groupbox; color: black; }</pre>
 
@@ -246,7 +246,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>listbox</code></td>
    <td>
-    <div id="sampleListBox" style="display: none;">
+    <div id="sampleListBox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: listbox; -webkit-appearance: listbox; height:20px; color: black; }</pre>
 
@@ -259,7 +259,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>listitem</code></td>
    <td>
-    <div id="sampleListItem" style="display: none;">
+    <div id="sampleListItem" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: listitem; -webkit-appearance: listitem; color: black; }</pre>
 
@@ -272,7 +272,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menuarrow</code></td>
    <td>
-    <div id="sampleMenuArrow" style="display: none;">
+    <div id="sampleMenuArrow" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menuarrow; -webkit-appearance: menuarrow; color: black; }</pre>
 
@@ -285,7 +285,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menubar</code></td>
    <td>
-    <div id="sampleMenubar" style="display: none;">
+    <div id="sampleMenubar" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menubar; -webkit-appearance: menubar; color: balck; }</pre>
 
@@ -298,7 +298,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menucheckbox</code></td>
    <td>
-    <div id="sampleMenuCheckbox" style="display: none;">
+    <div id="sampleMenuCheckbox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menucheckbox; -webkit-appearance: menucheckbox; color: black; }</pre>
 
@@ -311,7 +311,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menuimage</code></td>
    <td>
-    <div id="sampleMenuImage" style="display: none;">
+    <div id="sampleMenuImage" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menuimage; -webkit-appearance: menuimage; color: black; }</pre>
 
@@ -324,7 +324,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menuitem</code></td>
    <td>
-    <div id="sampleMenuItem" style="display: none;">
+    <div id="sampleMenuItem" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menuitem; -webkit-appearance: menuitem; color: black; }</pre>
 
@@ -337,7 +337,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menuitemtext</code></td>
    <td>
-    <div id="sampleMenuItemText" style="display: none;">
+    <div id="sampleMenuItemText" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menuitemtext; -webkit-appearance: menuitemtext; color: black; }</pre>
 
@@ -350,7 +350,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menulist</code></td>
    <td>
-    <div id="sampleMenuList" style="display: none;">
+    <div id="sampleMenuList" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menulist; -webkit-appearance: menulist; color: black; }</pre>
 
@@ -363,7 +363,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menulist-button</code></td>
    <td>
-    <div id="sampleMenuListButton" style="display: none;">
+    <div id="sampleMenuListButton" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menulist-button; -webkit-appearance: menulist-button; color: black; }</pre>
 
@@ -376,7 +376,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menulist-text</code></td>
    <td>
-    <div id="sampleMenuListText" style="display: none;">
+    <div id="sampleMenuListText" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menulist-text; -webkit-appearance: menulist-text; color: black; }</pre>
 
@@ -389,7 +389,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menulist-textfield</code></td>
    <td>
-    <div id="sampleMenuListTextfield" style="display: none;">
+    <div id="sampleMenuListTextfield" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menulist-textfield; -webkit-appearance: menulist-textfield; color: black; }</pre>
 
@@ -402,7 +402,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menupopup</code></td>
    <td>
-    <div id="sampleMenuPopup" style="display: none;">
+    <div id="sampleMenuPopup" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menupopup; -webkit-appearance: menupopup; color: black; }</pre>
 
@@ -415,7 +415,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menuradio</code></td>
    <td>
-    <div id="sampleMenuRadio" style="display: none;">
+    <div id="sampleMenuRadio" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menuradio; -webkit-appearance: menuradio; color: black; }</pre>
 
@@ -428,7 +428,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>menuseparator</code></td>
    <td>
-    <div id="sampleMenuSeparator" style="display: none;">
+    <div id="sampleMenuSeparator" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: menuseparator; -webkit-appearance: menuseparator; color: transparent; }</pre>
 
@@ -441,7 +441,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>meterbar</code></td>
    <td>
-    <div id="sampleMeterbar" style="display: none;">
+    <div id="sampleMeterbar" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: meterbar; -webkit-appearance: meterbar; color: black; }</pre>
 
@@ -454,7 +454,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>meterchunk</code></td>
    <td>
-    <div id="sampleMeterchunk" style="display: none;">
+    <div id="sampleMeterchunk" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: meterchunk; -webkit-appearance: meterchunk; color: black; }</pre>
 
@@ -467,7 +467,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>progressbar</code></td>
    <td>
-    <div id="sampleProgressBar" style="display: none;">
+    <div id="sampleProgressBar" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: progressbar; -webkit-appearance: progressbar; color: black; }</pre>
 
@@ -480,7 +480,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>progressbar-vertical</code></td>
    <td>
-    <div id="sampleProgressBarVertical" style="display: none;">
+    <div id="sampleProgressBarVertical" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: progressbar-vertical; -webkit-appearance: preogressbar-vertical; color: transparent; }</pre>
 
@@ -493,7 +493,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>progresschunk</code></td>
    <td>
-    <div id="sampleProgressChunk" style="display: none;">
+    <div id="sampleProgressChunk" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: progresschunk; -webkit-appearance: progresschunk; color: black; }</pre>
 
@@ -506,7 +506,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>progresschunk-vertical</code></td>
    <td>
-    <div id="sampleProgressChunkVertical" style="display: none;">
+    <div id="sampleProgressChunkVertical" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: progresschunk-vertical; -webkit-appearance: progresschunk-vertical; color: black; }</pre>
 
@@ -519,7 +519,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>radio</code></td>
    <td>
-    <div id="sampleRadio" style="display: none;">
+    <div id="sampleRadio" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: radio; -webkit-appearance: radio; color: black; }</pre>
 
@@ -532,7 +532,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>radio-container</code></td>
    <td>
-    <div id="sampleRadioContainer" style="display: none;">
+    <div id="sampleRadioContainer" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: radio-container; -webkit-appearance: radio-container; color: black; }</pre>
 
@@ -545,7 +545,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>radio-label</code></td>
    <td>
-    <div id="sampleRadioLabel" style="display: none;">
+    <div id="sampleRadioLabel" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: radio-label; -webkit-appearance: radio-label; color: black; }</pre>
 
@@ -558,7 +558,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>radiomenuitem</code></td>
    <td>
-    <div id="sampleRadioMenuItem" style="display: none;">
+    <div id="sampleRadioMenuItem" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: radiomenuitem; -webkit-appearance: radiomenuitem; color: black; }</pre>
 
@@ -571,7 +571,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>resizer</code></td>
    <td>
-    <div id="sampleResizer" style="display: none;">
+    <div id="sampleResizer" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: resizer; -webkit-appearance: resizer; color: transparent; }</pre>
 
@@ -584,7 +584,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>resizerpanel</code></td>
    <td>
-    <div id="sampleResizerPanel" style="display: none;">
+    <div id="sampleResizerPanel" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: resizerpanel; -webkit-appearance: resizerpanel; color: black; }</pre>
 
@@ -597,7 +597,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scale-horizontal</code></td>
    <td>
-    <div id="sampleScaleHorizontal" style="display: none;">
+    <div id="sampleScaleHorizontal" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scale-horizontal; -webkit-appearance: scale-horizontal; color: transparent; }</pre>
 
@@ -610,7 +610,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scalethumbend</code></td>
    <td>
-    <div id="sampleThumbEnd" style="display: none;">
+    <div id="sampleThumbEnd" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scalethumbend; -webkit-appearance: scalethumbend; color: black; }</pre>
 
@@ -623,7 +623,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scalethumb-horizontal</code></td>
    <td>
-    <div id="sampleScaleThumbHorizontal" style="display: none;">
+    <div id="sampleScaleThumbHorizontal" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scalethumb-horizontal; -webkit-appearance: scalethumb-horizontal; color: transparent; }</pre>
 
@@ -636,7 +636,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scalethumbstart</code></td>
    <td>
-    <div id="sampleScaleThumbStart" style="display: none;">
+    <div id="sampleScaleThumbStart" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scalethumbstart; -webkit-appearance: scalethumbstart; color: black; }</pre>
 
@@ -649,7 +649,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scalethumbtick</code></td>
    <td>
-    <div id="sampleScaleThumbTick" style="display: none;">
+    <div id="sampleScaleThumbTick" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scalethumbtick; -webkit-appearance: scalethumbtick; color: black; }</pre>
 
@@ -662,7 +662,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scalethumb-vertical</code></td>
    <td>
-    <div id="sampleScaleThumbVertical" style="display: none;">
+    <div id="sampleScaleThumbVertical" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scalethumb-vertical; -webkit-appearance: scalethumb-vertical; color: black; }</pre>
 
@@ -675,7 +675,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scale-vertical</code></td>
    <td>
-    <div id="sampleScaleVertical" style="display: none;">
+    <div id="sampleScaleVertical" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scale-vertical; -webkit-appearance: scale-vertical; color: transparent; }</pre>
 
@@ -688,7 +688,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbarbutton-down</code></td>
    <td>
-    <div id="sampleScrollbarButtonDown" style="display: none;">
+    <div id="sampleScrollbarButtonDown" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbarbutton-down; -webkit-appearance: scrollbarbutton-down; color: black; }</pre>
 
@@ -701,7 +701,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbarbutton-left</code></td>
    <td>
-    <div id="sampleScrollbarButtonLeft" style="display: none;">
+    <div id="sampleScrollbarButtonLeft" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbarbutton-left; -webkit-appearance: scrollbarbutton-left; color: black; }</pre>
 
@@ -714,7 +714,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbarbutton-right</code></td>
    <td>
-    <div id="sampleScrollbarButtonRight" style="display: none;">
+    <div id="sampleScrollbarButtonRight" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbarbutton-right; -webkit-appearance: scrollbarbutton-right; color: black; }</pre>
 
@@ -727,7 +727,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbarbutton-up</code></td>
    <td>
-    <div id="sampleScrollbarButtonUp" style="display: none;">
+    <div id="sampleScrollbarButtonUp" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbarbutton-up; -webkit-appearance: scrollbarbutton-up; color: black; }</pre>
 
@@ -740,7 +740,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbarthumb-horizontal</code></td>
    <td>
-    <div id="sampleScrollbarThumbHorizontal" style="display: none;">
+    <div id="sampleScrollbarThumbHorizontal" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbarthumb-horizontal; -webkit-appearance: scrollbarthumb-horizontal; color: black; }</pre>
 
@@ -753,7 +753,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbarthumb-vertical</code></td>
    <td>
-    <div id="sampleScrollbarThumbVertical" style="display: none;">
+    <div id="sampleScrollbarThumbVertical" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbarthumb-vertical; -webkit-appearance: scrollbarthumb-vertical; color: black; }</pre>
 
@@ -766,7 +766,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbartrack-horizontal</code></td>
    <td>
-    <div id="sampleScrollbarTrackHorizontal" style="display: none;">
+    <div id="sampleScrollbarTrackHorizontal" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbartrack-horizontal; -webkit-appearance: scrollbartrack-horizontal; color: black; }</pre>
 
@@ -779,7 +779,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>scrollbartrack-vertical</code></td>
    <td>
-    <div id="sampleScrollbarTrackVertical" style="display: none;">
+    <div id="sampleScrollbarTrackVertical" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: scrollbartrack-vertical; -webkit-appearance: scrollbarbartrack-vertical; color: black; }</pre>
 
@@ -792,7 +792,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>searchfield</code></td>
    <td>
-    <div id="sampleSearchField" style="display: none;">
+    <div id="sampleSearchField" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: searchfield; -webkit-appearance: searchfield; color: black; }</pre>
 
@@ -805,7 +805,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>separator</code></td>
    <td>
-    <div id="sampleSeparator" style="display: none;">
+    <div id="sampleSeparator" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: separator; -webkit-appearance: separator; color: transparent; }</pre>
 
@@ -818,7 +818,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>sheet</code></td>
    <td>
-    <div id="sampleSheet" style="display: none;">
+    <div id="sampleSheet" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: sheet; -webkit-appearance: sheet; color: black; }</pre>
 
@@ -831,7 +831,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>spinner</code></td>
    <td>
-    <div id="sampleSpinner" style="display: none;">
+    <div id="sampleSpinner" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: spinner; -webkit-appearance: spinner; color: transparent; }</pre>
 
@@ -844,7 +844,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>spinner-downbutton</code></td>
    <td>
-    <div id="sampleSpinnerDownbutton" style="display: none;">
+    <div id="sampleSpinnerDownbutton" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: spinner-downbutton; -webkit-appearance: spinner-downbutton; color: black; }</pre>
 
@@ -857,7 +857,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>spinner-textfield</code></td>
    <td>
-    <div id="sampleSpinnerTextfield" style="display: none;">
+    <div id="sampleSpinnerTextfield" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: spinner-textfield; -webkit-appearance: spinner-textfield; color: black; }</pre>
 
@@ -870,7 +870,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>spinner-upbutton</code></td>
    <td>
-    <div id="sampleSpinnerUpbutton" style="display: none;">
+    <div id="sampleSpinnerUpbutton" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: spinner-upbutton; -webkit-appearance: spinner-upbutton; color: black; }</pre>
 
@@ -883,7 +883,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>splitter</code></td>
    <td>
-    <div id="sampleSplitter" style="display: none;">
+    <div id="sampleSplitter" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: splitter; -webkit-appearance: splitter; color: transparent; }</pre>
 
@@ -896,7 +896,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>statusbar</code></td>
    <td>
-    <div id="sampleStatusBar" style="display: none;">
+    <div id="sampleStatusBar" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: statusbar; -webkit-appearance: statusbar; color: black; }</pre>
 
@@ -909,7 +909,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>statusbarpanel</code></td>
    <td>
-    <div id="sampleStatusBarPanel" style="display: none;">
+    <div id="sampleStatusBarPanel" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: statusbarpanel; -webkit-appearance: statusbarpanel; color: black; }</pre>
 
@@ -922,7 +922,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>tab</code></td>
    <td>
-    <div id="sampleTab" style="display: none;">
+    <div id="sampleTab" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: tab; -webkit-appearance: tab; height: 20px; color: black; }</pre>
 
@@ -935,7 +935,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>tabpanel</code></td>
    <td>
-    <div id="sampleTabPanel" style="display: none;">
+    <div id="sampleTabPanel" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: tabpanel; -webkit-appearance: tabpanel; color: black; }</pre>
 
@@ -948,7 +948,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>tabpanels</code></td>
    <td>
-    <div id="sampleTabPanels" style="display: none;">
+    <div id="sampleTabPanels" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: tabpanels; -webkit-appearance: tabpanels; color: black; }</pre>
 
@@ -961,7 +961,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>tab-scroll-arrow-back</code></td>
    <td>
-    <div id="sampleTabScrollArrowBack" style="display: none;">
+    <div id="sampleTabScrollArrowBack" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: tab-scroll-arrow-back; -webkit-appearance: tab-scroll-arrow-back; color: black; }</pre>
 
@@ -974,7 +974,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>tab-scroll-arrow-forward</code></td>
    <td>
-    <div id="sampleTabScrollArrowForward" style="display: none;">
+    <div id="sampleTabScrollArrowForward" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: tab-scroll-arrow-forward; -webkit-appearance: tab-scroll-arrow-forward; color: black; }</pre>
 
@@ -987,7 +987,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>textfield</code></td>
    <td>
-    <div id="sampleTextField" style="display: none;">
+    <div id="sampleTextField" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: textfield; -webkit-appearance: textfield; color: black; }</pre>
 
@@ -1000,7 +1000,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>textfield-multiline</code></td>
    <td>
-    <div id="sampleTextfieldMultiline" style="display: none;">
+    <div id="sampleTextfieldMultiline" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: textfield-multiline; -webkit-appearance: textfield-multiline; color: black; }</pre>
 
@@ -1013,7 +1013,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>toolbar</code></td>
    <td>
-    <div id="sampleToolbar" style="display: none;">
+    <div id="sampleToolbar" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: toolbar; -webkit-appearance: toolbar; color: black; }</pre>
 
@@ -1026,7 +1026,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>toolbarbutton</code></td>
    <td>
-    <div id="sampleToolbarButton" style="display: none;">
+    <div id="sampleToolbarButton" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: toolbarbutton; -webkit-appearance: toolbarbutton; color: black; }</pre>
 
@@ -1039,7 +1039,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>toolbarbutton-dropdown</code></td>
    <td>
-    <div id="sampleToolbarButtonDropdown" style="display: none;">
+    <div id="sampleToolbarButtonDropdown" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: toolbarbutton-dropdown; -webkit-appearance: toolbarbutton-dropdown; color: black; }</pre>
 
@@ -1052,7 +1052,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>toolbargripper</code></td>
    <td>
-    <div id="sampleToolbarGripper" style="display: none;">
+    <div id="sampleToolbarGripper" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: toolbargripper; -webkit-appearance: toolbargripper; color: black; }</pre>
 
@@ -1065,7 +1065,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>toolbox</code></td>
    <td>
-    <div id="sampleToolbox" style="display: none;">
+    <div id="sampleToolbox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: toolbox; -webkit-appearance: toolbox; color: black; }</pre>
 
@@ -1078,7 +1078,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>tooltip</code></td>
    <td>
-    <div id="sampleTooltip" style="display: none;">
+    <div id="sampleTooltip" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: tooltip; -webkit-appearance: tooltip; color: black; }</pre>
 
@@ -1091,7 +1091,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treeheader</code></td>
    <td>
-    <div id="sampleTreeHeader" style="display: none;">
+    <div id="sampleTreeHeader" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treeheader; -webkit-appearance: treeheader; color: black; }</pre>
 
@@ -1104,7 +1104,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treeheadercell</code></td>
    <td>
-    <div id="sampleTreeHeaderCell" style="display: none;">
+    <div id="sampleTreeHeaderCell" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treeheadercell; -webkit-appearance: treeheadercell; height:20px; color: black; }</pre>
 
@@ -1117,7 +1117,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treeheadersortarrow</code></td>
    <td>
-    <div id="sampleTreeHeaderSortArrow" style="display: none;">
+    <div id="sampleTreeHeaderSortArrow" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treeheadersortarrow; -webkit-appearance: treeheadersortarrow; color: black; }</pre>
 
@@ -1130,7 +1130,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treeitem</code></td>
    <td>
-    <div id="sampleTreeItem" style="display: none;">
+    <div id="sampleTreeItem" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treeitem; -webkit-appearance: treeitem; color: black; }</pre>
 
@@ -1143,7 +1143,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treeline</code></td>
    <td>
-    <div id="sampleTreeLine" style="display: none;">
+    <div id="sampleTreeLine" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treeline; -webkit-appearance: treeline; color: black; }</pre>
 
@@ -1156,7 +1156,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treetwisty</code></td>
    <td>
-    <div id="sampleTreeTwisty" style="display: none;">
+    <div id="sampleTreeTwisty" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treetwisty; -webkit-appearance: treetwisty; color: transparent; }</pre>
 
@@ -1169,7 +1169,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treetwistyopen</code></td>
    <td>
-    <div id="sampleTreeTwistyOpen" style="display: none;">
+    <div id="sampleTreeTwistyOpen" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treetwistyopen; -webkit-appearance: treetwistyopen; color: transparent; }</pre>
 
@@ -1182,7 +1182,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>treeview</code></td>
    <td>
-    <div id="sampleTreeView" style="display: none;">
+    <div id="sampleTreeView" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: treeview; -webkit-appearance: treeview; color: black; }</pre>
 
@@ -1195,7 +1195,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-mac-unified-toolbar</code></td>
    <td>
-    <div id="sampleMacUnifiedToolbar" style="display: none;">
+    <div id="sampleMacUnifiedToolbar" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-mac-unified-toolbar; color: black; }</pre>
 
@@ -1208,7 +1208,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td>{{ gecko_minversion_inline("2.0") }} <code>-moz-win-borderless-glass</code></td>
    <td>
-    <div id="sampleWinBorderlessGlass" style="display: none;">
+    <div id="sampleWinBorderlessGlass" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-borderless-glass; color: black; }</pre>
 
@@ -1221,7 +1221,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-win-browsertabbar-toolbox</code></td>
    <td>
-    <div id="sampleWinBrowsertabbarToolbox" style="display: none;">
+    <div id="sampleWinBrowsertabbarToolbox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-browsertabbar-toolbox; color: black; }</pre>
 
@@ -1234,7 +1234,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-win-communicationstext</code></td>
    <td>
-    <div id="sampleWinCommunicationstext" style="display: none;">
+    <div id="sampleWinCommunicationstext" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-communicationstext; color: black; }</pre>
 
@@ -1247,7 +1247,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-win-communications-toolbox</code></td>
    <td>
-    <div id="sampleWinCommunicationsToolbox" style="display: none;">
+    <div id="sampleWinCommunicationsToolbox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-communications-toolbox; color: black; }</pre>
 
@@ -1260,7 +1260,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td>{{gecko_minversion_inline("6.0")}} <code>-moz-win-exclude-glass</code></td>
    <td>
-    <div id="sampleWinExcludeGlass" style="display: none;">
+    <div id="sampleWinExcludeGlass" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-exclude-glass; color: black; }</pre>
 
@@ -1273,7 +1273,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-win-glass</code></td>
    <td>
-    <div id="sampleWinGlass" style="display: none;">
+    <div id="sampleWinGlass" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-glass; color: black; }</pre>
 
@@ -1286,7 +1286,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-win-mediatext</code></td>
    <td>
-    <div id="sampleWinMediaText" style="display: none;">
+    <div id="sampleWinMediaText" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-mediatext; color: black; }</pre>
 
@@ -1299,7 +1299,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-win-media-toolbox</code></td>
    <td>
-    <div id="sampleWinMediaToolbox" style="display: none;">
+    <div id="sampleWinMediaToolbox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-win-media-toolbox; color: black; }</pre>
 
@@ -1312,7 +1312,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-button-box</code></td>
    <td>
-    <div id="sampleWindowButtonBox" style="display: none;">
+    <div id="sampleWindowButtonBox" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-button-box; color: black; }</pre>
 
@@ -1325,7 +1325,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-button-box-maximized</code></td>
    <td>
-    <div id="sampleWindowButtonBoxMaximized" style="display: none;">
+    <div id="sampleWindowButtonBoxMaximized" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-button-box-maximized; color: black; }</pre>
 
@@ -1338,7 +1338,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-button-close</code></td>
    <td>
-    <div id="sampleWindowButtonClose" style="display: none;">
+    <div id="sampleWindowButtonClose" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-button-close; color: black; }</pre>
 
@@ -1351,7 +1351,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-button-maximize</code></td>
    <td>
-    <div id="sampleWindowButtonMaximize" style="display: none;">
+    <div id="sampleWindowButtonMaximize" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-button-maximize; color: black; }</pre>
 
@@ -1364,7 +1364,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-button-minimize</code></td>
    <td>
-    <div id="sampleWindowButtonMinimize" style="display: none;">
+    <div id="sampleWindowButtonMinimize" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-button-minimize; color: black; }</pre>
 
@@ -1377,7 +1377,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-button-restore</code></td>
    <td>
-    <div id="sampleWindowButtonRestore" style="display: none;">
+    <div id="sampleWindowButtonRestore" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-button-restore; color: black; }</pre>
 
@@ -1390,7 +1390,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-frame-bottom</code></td>
    <td>
-    <div id="sampleWindowFrameBottom" style="display: none;">
+    <div id="sampleWindowFrameBottom" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-frame-bottom; color: black; }</pre>
 
@@ -1403,7 +1403,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-frame-left</code></td>
    <td>
-    <div id="sampleWindowFrameLeft" style="display: none;">
+    <div id="sampleWindowFrameLeft" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-frame-left; color: black; }</pre>
 
@@ -1416,7 +1416,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-frame-right</code></td>
    <td>
-    <div id="sampleWindowFrameRight" style="display: none;">
+    <div id="sampleWindowFrameRight" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-frame-right; color: black; }</pre>
 
@@ -1429,7 +1429,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-titlebar</code></td>
    <td>
-    <div id="sampleWindowTitlebar" style="display: none;">
+    <div id="sampleWindowTitlebar" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-titlebar; color: black; }</pre>
 
@@ -1442,7 +1442,7 @@ translation_of: Web/CSS/appearance
   <tr>
    <td><code>-moz-window-titlebar-maximized</code></td>
    <td>
-    <div id="sampleWindowTitlebarMaximized" style="display: none;">
+    <div id="sampleWindowTitlebarMaximized" class="hidden">
     <pre class="brush:css">
  div {-moz-appearance: -moz-window-titlebar-maximized; color: black; }</pre>
 
diff --git a/files/de/web/css/css_background_and_borders/border-image_generator/index.html b/files/de/web/css/css_background_and_borders/border-image_generator/index.html
index ff2740480a..7e223feb3d 100644
--- a/files/de/web/css/css_background_and_borders/border-image_generator/index.html
+++ b/files/de/web/css/css_background_and_borders/border-image_generator/index.html
@@ -8,7 +8,7 @@ translation_of: Web/CSS/CSS_Background_and_Borders/Border-image_generator
 ---
 <p>Dieses Werkzeug kann dazu verwendet werden, CSS3 {{cssxref("border-image")}} Werte zu erzeugen.</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h2 id="Border_Image_Generator" name="Border_Image_Generator">Border Image Generator</h2>
 
 <h3 id="HTML_Content">HTML Content</h3>
diff --git a/files/de/web/css/css_background_and_borders/border-radius_generator/index.html b/files/de/web/css/css_background_and_borders/border-radius_generator/index.html
index 0193a207e7..ced3cae5ad 100644
--- a/files/de/web/css/css_background_and_borders/border-radius_generator/index.html
+++ b/files/de/web/css/css_background_and_borders/border-radius_generator/index.html
@@ -8,7 +8,7 @@ translation_of: Web/CSS/CSS_Background_and_Borders/Border-radius_generator
 ---
 <p>Dieses Werkzeug kann dazu verwendet werden, CSS3 {{cssxref("border-radius")}} Effekte zu erzeugen.</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h2 id="border-radius-generator" name="border-radius-generator">border-radius</h2>
 
 <h3 id="HTML_Content">HTML Content</h3>
diff --git a/files/de/web/css/css_background_and_borders/box-shadow_generator/index.html b/files/de/web/css/css_background_and_borders/box-shadow_generator/index.html
index 0737e34004..9ced969467 100644
--- a/files/de/web/css/css_background_and_borders/box-shadow_generator/index.html
+++ b/files/de/web/css/css_background_and_borders/box-shadow_generator/index.html
@@ -10,7 +10,7 @@ original_slug: Web/CSS/CSS_Boxmodell/Box-shadow_generator
 ---
 <p>Dieses Werkzeug erlaubt es, CSS {{cssxref("box-shadow")}} Effekte zu erstellen, um Schlagschatteneffekte zu CSS Objekten hinzuzufügen.</p>
 
-<div style="display: none;">
+<div class="hidden">
 <h2 id="box-shadow_generator" name="box-shadow_generator">box-shadow generator</h2>
 
 <h3 id="HTML_Content">HTML Content</h3>
@@ -1178,7 +1178,7 @@ body {
 
 <h3 id="JavaScript_Content">JavaScript Content</h3>
 
-<pre class="brush: js"><code class="language-js">
+<pre class="brush: js">
 
 'use strict';
 
@@ -2877,7 +2877,7 @@ var BoxShadow = (function BoxShadow() {
 })();
 
 
-</code></pre>
+</pre>
 </div>
 
 <div>{{ EmbedLiveSample('box-shadow_generator', '100%', '1100px', '') }}</div>
diff --git a/files/de/web/css/css_colors/color_picker_tool/index.html b/files/de/web/css/css_colors/color_picker_tool/index.html
index ae206cc90a..e0f80ba4ed 100644
--- a/files/de/web/css/css_colors/color_picker_tool/index.html
+++ b/files/de/web/css/css_colors/color_picker_tool/index.html
@@ -11,7 +11,7 @@ tags:
 translation_of: Web/CSS/CSS_Colors/Color_picker_tool
 original_slug: Web/CSS/CSS_Colors/farbauswahl_werkzeug
 ---
-<div style="display: none;">
+<div class="hidden">
 <h2 id="ColorPicker_Tool" name="ColorPicker_Tool">ColorPicker tool</h2>
 
 <h3 id="HTML_Content">HTML Content</h3>
diff --git a/files/de/web/css/filter/index.html b/files/de/web/css/filter/index.html
index 04901d5c3a..21612a2036 100644
--- a/files/de/web/css/filter/index.html
+++ b/files/de/web/css/filter/index.html
@@ -76,7 +76,7 @@ img {
 <pre class="brush: css">filter: blur(5px)
 </pre>
 
-<div id="blur_example" style="display: none;">
+<div id="blur_example" class="hidden">
 <pre class="brush: html">  &lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -171,7 +171,7 @@ table.standard-table td {
   &lt;/filter&gt;
 &lt;/svg&gt;</pre>
 
-<div id="brightness_example" style="display: none;">
+<div id="brightness_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -267,7 +267,7 @@ table.standard-table td {
 &lt;/svg&gt;
 </pre>
 
-<div id="contrast_example" style="display: none;">
+<div id="contrast_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -379,7 +379,7 @@ table.standard-table td {
 &lt;/svg&gt;
 </pre>
 
-<div id="shadow_example" style="display: none;">
+<div id="shadow_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -465,7 +465,7 @@ table.standard-table td {
 
 <pre class="brush: css">filter: grayscale(100%)</pre>
 
-<div id="grayscale_example" style="display: none;">
+<div id="grayscale_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -549,7 +549,7 @@ table.standard-table td {
 
 <pre class="brush: css">filter: hue-rotate(90deg)</pre>
 
-<div id="huerotate_example" style="display: none;">
+<div id="huerotate_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -630,7 +630,7 @@ table.standard-table td {
 
 <pre class="brush: css">filter: invert(100%)</pre>
 
-<div id="invert_example" style="display: none;">
+<div id="invert_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -714,7 +714,7 @@ table.standard-table td {
 
 <pre class="brush: css">filter: opacity(50%)</pre>
 
-<div id="opacity_example" style="display: none;">
+<div id="opacity_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -796,7 +796,7 @@ table.standard-table td {
 
 <pre class="brush: css">filter: saturate(200%)</pre>
 
-<div id="saturate_example" style="display: none;">
+<div id="saturate_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -877,7 +877,7 @@ table.standard-table td {
 
 <pre class="brush: css">filter: sepia(100%)</pre>
 
-<div id="sepia_example" style="display: none;">
+<div id="sepia_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
@@ -961,7 +961,7 @@ table.standard-table td {
 
 <pre class="brush: css">filter: contrast(175%) brightness(3%)</pre>
 
-<div id="combination_example" style="display: none;">
+<div id="combination_example" class="hidden">
 <pre class="brush: html">&lt;table class="standard-table"&gt;
   &lt;thead&gt;
     &lt;tr&gt;
diff --git a/files/de/web/css/gradient/index.html b/files/de/web/css/gradient/index.html
index dcec7d40b2..a9f0423ad3 100644
--- a/files/de/web/css/gradient/index.html
+++ b/files/de/web/css/gradient/index.html
@@ -21,7 +21,7 @@ translation_of: Web/CSS/gradient
 <ul>
  <li id="linear-gradient"><em>Lineare Farbverläufe</em>, erzeugt durch die {{cssxref("linear-gradient()")}} Funktion, wo die Farbe weich entlang einer imaginären Linie verläuft.
 
-  <pre class="brush: html" style="display: none;">Ein durch einen Farbverlauf erzeugter Regenbogen
+  <pre class="brush: html" class="hidden">Ein durch einen Farbverlauf erzeugter Regenbogen
 </pre>
 
   <pre class="brush: css">body {
@@ -35,7 +35,7 @@ background: linear-gradient(to right,red,orange,yellow, green, blue,indigo,viole
   <p>{{EmbedLiveSample('linear-gradient', 600, 20)}}</p>
  </li>
  <li id="radial-gradient"><em>Radiale Farbverläufe</em>, erzeugt durch die {{cssxref("radial-gradient()")}} Funktion. Je weiter sich ein Punkt vom Ursprung entfernt befindet, desto weiter entfernt ist er von der Originalfarbe.
-  <pre class="brush: html" style="display: none;">Radialer Farbverlauf
+  <pre class="brush: html" class="hidden">Radialer Farbverlauf
   </pre>
 
   <pre class="brush: css">body {
@@ -47,7 +47,7 @@ background: radial-gradient(red, yellow, rgb(30, 144, 255));
   <p>{{EmbedLiveSample('radial-gradient', 600, 20)}}</p>
  </li>
  <li id="repeating-gradient"><em>Wiederholende Farbverläufe</em>, welche lineare oder radiale Farbverläufe fester Größe sind, die sich solange wiederholen bis die gesamte Box gefüllt ist.
-  <pre class="brush: html" style="display: none;">Wiederholender Farbverlauf
+  <pre class="brush: html" class="hidden">Wiederholender Farbverlauf
 </pre>
 
   <pre class="brush: css">body {
diff --git a/files/de/web/css/resize/index.html b/files/de/web/css/resize/index.html
index 82162a06bf..930ecf5f8c 100644
--- a/files/de/web/css/resize/index.html
+++ b/files/de/web/css/resize/index.html
@@ -88,9 +88,8 @@ resize: unset;
 }  </pre>
 
 <div id="Disabling_resizability_of_textareas">
-<pre class="brush: html notranslate" style="display: none;">&lt;textarea&gt;Type some text here.&lt;/textarea&gt;</pre>
 
-<pre class="brush: css notranslate" style="display: none;">textarea {
+<pre class="brush: css notranslate" class="hidden">textarea {
   resize: none; /* Disables resizability */
 }  </pre>
 </div>
diff --git a/files/de/web/css/tools/cubic_bezier_generator/index.html b/files/de/web/css/tools/cubic_bezier_generator/index.html
index a385d685be..a401f734aa 100644
--- a/files/de/web/css/tools/cubic_bezier_generator/index.html
+++ b/files/de/web/css/tools/cubic_bezier_generator/index.html
@@ -7,7 +7,7 @@ tags:
 translation_of: Web/CSS/Tools/Cubic_Bezier_Generator
 ---
 <div id="Tool">
-<div style="display: none;">
+<div class="hidden">
 <pre class="brush:html">&lt;html&gt;
     &lt;canvas id="bezier" width="336" height="336"&gt;
     &lt;/canvas&gt;
diff --git a/files/de/web/css/tools/linear-gradient_generator/index.html b/files/de/web/css/tools/linear-gradient_generator/index.html
index bc5f7b2465..dbdafdfe28 100644
--- a/files/de/web/css/tools/linear-gradient_generator/index.html
+++ b/files/de/web/css/tools/linear-gradient_generator/index.html
@@ -6,7 +6,7 @@ tags:
   - Werkzeuge
 translation_of: Web/CSS/Tools/Linear-gradient_Generator
 ---
-<div style="display: none;">
+<div class="hidden">
 <h2 id="linear-gradient_generator" name="linear-gradient_generator">linear-gradient generator</h2>
 
 <h3 id="HTML_Content">HTML Content</h3>
diff --git a/files/de/web/javascript/reference/global_objects/math/cos/index.html b/files/de/web/javascript/reference/global_objects/math/cos/index.html
index 300908a90b..e8e5c3bf86 100644
--- a/files/de/web/javascript/reference/global_objects/math/cos/index.html
+++ b/files/de/web/javascript/reference/global_objects/math/cos/index.html
@@ -10,7 +10,7 @@ translation_of: Web/JavaScript/Reference/Global_Objects/Math/cos
 ---
 <div>{{JSRef}}</div>
 
-<p>Die <strong><code>Math.cos()</code></strong> Funktion gibt den <span class="seoSummary">{{interwiki("wikipedia", "Cosinus")}}</span> eines Winkels zurück. Der Winkel muss im <span class="seoSummary">{{interwiki("wikipedia", "Bogenmaß")}}</span> angegeben werden. Der Wert ist <math style="display: inline;"> <mstyle displaystyle="true"> <mfrac> <msub> <mrow> <mtext>length</mtext> </mrow> <mrow> <mrow> <mtext>adjacent</mtext> </mrow> </mrow> </msub> <msub> <mrow> <mtext>length</mtext> </mrow> <mrow> <mrow> <mtext>hypotenuse</mtext> </mrow> </mrow> </msub> </mfrac> </mstyle> </math>.<span style="display: none;"> </span></p>
+<p>Die <strong><code>Math.cos()</code></strong> Funktion gibt den <span class="seoSummary">{{interwiki("wikipedia", "Cosinus")}}</span> eines Winkels zurück. Der Winkel muss im <span class="seoSummary">{{interwiki("wikipedia", "Bogenmaß")}}</span> angegeben werden. Der Wert ist <math style="display: inline;"> <mstyle displaystyle="true"> <mfrac> <msub> <mrow> <mtext>length</mtext> </mrow> <mrow> <mrow> <mtext>adjacent</mtext> </mrow> </mrow> </msub> <msub> <mrow> <mtext>length</mtext> </mrow> <mrow> <mrow> <mtext>hypotenuse</mtext> </mrow> </mrow> </msub> </mfrac> </mstyle> </math>.<span class="hidden"> </span></p>
 
 <div>{{EmbedInteractiveExample("pages/js/math-cos.html")}}</div>
 
diff --git a/files/de/web/javascript/reference/global_objects/promise/index.html b/files/de/web/javascript/reference/global_objects/promise/index.html
index 9e9756ac65..31b7e276a4 100644
--- a/files/de/web/javascript/reference/global_objects/promise/index.html
+++ b/files/de/web/javascript/reference/global_objects/promise/index.html
@@ -90,7 +90,6 @@ new Promise(function(resolve, reject) { ... });</pre>
 
 <h3 id="Einen_Promise_erstellen">Einen Promise erstellen</h3>
 
-<pre class="brush: html notranslate" style="display: none;">&lt;button id="btn"&gt;Make a promise!&lt;/button&gt;
 &lt;div id="log"&gt;&lt;/div&gt;
 </pre>
 
@@ -134,7 +133,7 @@ function testPromise() {
 }
 </pre>
 
-<pre class="brush:js notranslate" style="display: none;">if ("Promise" in window) {
+<pre class="brush:js notranslate" class="hidden">if ("Promise" in window) {
   btn = document.getElementById("btn");
    btn.addEventListener("click",testPromise);
 }