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

70 files changed, 192 insertions, 192 deletions

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index 96a1ff04a9..d1ad7e7139 100644
--- a/files/pt-pt/conflicting/web/progressive_web_apps/responsive/responsive_design_building_blocks/index.html
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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@@ -95,7 +95,7 @@ original_slug: Web/Progressive_web_apps/Responsivo
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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 <div id="SL_alert_cont"> </div>
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@@ -40,7 +40,7 @@ original_slug: Glossário/Compilar
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@@ -54,7 +54,7 @@ original_slug: Glossário/Hipertexto
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index 45284b8764..44c2f1535b 100644
--- a/files/pt-pt/learn/html/howto/index.html
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-<p><span style="display: none;"> </span><span style="display: none;"> </span><span style="display: none;"> </span><span style="display: none;"> </span> </p>
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index d1aab102ec..d6b77c0bcb 100644
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@@ -546,7 +546,7 @@ window.addEventListener("load", drawOutput);
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index 8693cf24a5..5f7c0c37b9 100644
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@@ -284,7 +284,7 @@ and HTML5 Apps. It also documents Mozilla products, like Firefox OS."&gt;
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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@@ -307,7 +307,7 @@ This is the second.
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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@@ -476,7 +476,7 @@ tfoot {
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-<div id="SL_alert_bbl" style="display: none;">
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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@@ -584,7 +584,7 @@ original_slug: Learn/HTML/Tables/Basicos
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 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/learn/html/tables/index.html b/files/pt-pt/learn/html/tables/index.html
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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@@ -58,7 +58,7 @@ translation_of: Learn/HTML/Tables
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-<div id="SL_alert_bbl" style="display: none;">
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 <div id="SL_alert_cont"> </div>
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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@@ -89,7 +89,7 @@ original_slug: Learn/HTML/Tables/Avaliacao_Estruturar_os_dados_dos_planetas
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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 <div id="SL_alert_cont"> </div>
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index c032772810..686bc9d07d 100644
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 <div id="SL_alert_cont"> </div>
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+++ b/files/pt-pt/mozilla/add-ons/webextensions/api/sidebaraction/index.html
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 <div id="SL_balloon_obj" style="display: block;">
-<div class="SL_ImTranslatorLogo" id="SL_button" style="display: none;"> </div>
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
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@@ -114,7 +114,7 @@ translation_of: Mozilla/Add-ons/WebExtensions/API/sidebarAction
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style=""> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/mozilla/add-ons/webextensions/user_interface/popups/index.html b/files/pt-pt/mozilla/add-ons/webextensions/user_interface/popups/index.html
index 043afd3ad5..7d7c1d469e 100644
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+++ b/files/pt-pt/mozilla/add-ons/webextensions/user_interface/popups/index.html
@@ -19,7 +19,7 @@ original_slug: Mozilla/Add-ons/WebExtensions/interface_do_utilizador/Popups
 
 <p>Quando o usuário clica no botão, a janela popup é exibida. Quando o usuário clica em qualquer lugar fora do popup, ele é fechado. O popup pode ser fechado via programação usando a função <code><a href="https://developer.mozilla.org/en-US/docs/Web/API/Window/close">window.close()</a></code> em um script sendo executado no popup. Entretanto, você não pode abrir o popup via programação a partir do código JavaScript da extensão: ele somente se abre em resposta a uma ação do usuário.</p>
 
-<p>Você pode definir um atalho de teclado que abre o popup usando <code>"_execute_browser_action"</code> and <code>"_execute_page_action"</code>. Veja a documentação da chave <code><a href="/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/commands">commands</a></code><span style="display: none;">      </span> no manifest.json.</p>
+<p>Você pode definir um atalho de teclado que abre o popup usando <code>"_execute_browser_action"</code> and <code>"_execute_page_action"</code>. Veja a documentação da chave <code><a href="/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/commands">commands</a></code><span class="hidden">      </span> no manifest.json.</p>
 
 <h2 id="Especificar_uma_janela">Especificar uma janela</h2>
 
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 <h2 id="Emissões_de_ephemera">Emissões de ephemera</h2>
 
 <ul>
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+ <li><a href="https://twitter.com/mozhacks" title="https://twitter.com/mozhacks"><span id="cke_bm_286S" class="hidden"> </span></a><a href="http://twitter.com/MozDevNet">@MozDevNet</a>: Curated feed of new pages, significant updates, and other news about Mozilla Developer Network.</li>
  <li><a href="https://twitter.com/mozhacks" title="https://twitter.com/mozhacks">@MozHacks</a>: Tweets about new web technologies, great HTML5 apps, and Firefox features.</li>
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--- a/files/pt-pt/tools/page_inspector/how_to/work_with_animations/index.html
+++ b/files/pt-pt/tools/page_inspector/how_to/work_with_animations/index.html
@@ -67,7 +67,7 @@ original_slug: Tools/Page_Inspector/How_to/Trabalhar_com_animacoes
  <li>Each element had two properties animated:
   <ul>
    <li><code><a href="/en-US/docs/Web/CSS/width">width</a></code> and <code><a href="/en-US/docs/Web/CSS/opacity">opacity</a></code> for the channel name</li>
-   <li><code><a href="/en-US/docs/Web/CSS/filter">filter</a></code> and <code><a href="/en-US/docs/Web/CSS/transform">transform</a></code> for the icon.<span style="display: none;"> </span><span style="display: none;"> </span><span style="display: none;"> </span></li>
+   <li><code><a href="/en-US/docs/Web/CSS/filter">filter</a></code> and <code><a href="/en-US/docs/Web/CSS/transform">transform</a></code> for the icon.<span class="hidden"> </span><span class="hidden"> </span><span class="hidden"> </span></li>
   </ul>
  </li>
  <li>The <code>filter</code> property had a delay of 0.25 seconds applied to it.</li>
diff --git a/files/pt-pt/tools/page_inspector/keyboard_shortcuts/index.html b/files/pt-pt/tools/page_inspector/keyboard_shortcuts/index.html
index daa382cf26..07699f08e9 100644
--- a/files/pt-pt/tools/page_inspector/keyboard_shortcuts/index.html
+++ b/files/pt-pt/tools/page_inspector/keyboard_shortcuts/index.html
@@ -13,9 +13,9 @@ original_slug: Tools/Page_Inspector/atalhos_de_teclado
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; display: none; opacity: 1; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -27,7 +27,7 @@ original_slug: Tools/Page_Inspector/atalhos_de_teclado
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/tools/performance/call_tree/index.html b/files/pt-pt/tools/performance/call_tree/index.html
index 517e5ccdcf..4096b5d59d 100644
--- a/files/pt-pt/tools/performance/call_tree/index.html
+++ b/files/pt-pt/tools/performance/call_tree/index.html
@@ -113,9 +113,9 @@ original_slug: Tools/Desempenho/Arvore_de_Chamada
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 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 1; display: none; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
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 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -127,7 +127,7 @@ original_slug: Tools/Desempenho/Arvore_de_Chamada
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
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 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/tools/performance/index.html b/files/pt-pt/tools/performance/index.html
index 2b6d828b1d..02d62da901 100644
--- a/files/pt-pt/tools/performance/index.html
+++ b/files/pt-pt/tools/performance/index.html
@@ -105,9 +105,9 @@ original_slug: Tools/Desempenho
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-<div id="SL_shadow_translation_result2" style="display: none;"></div>
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-<div id="SL_shadow_translator" style="display: none;">
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@@ -119,7 +119,7 @@ original_slug: Tools/Desempenho
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
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-<div id="SL_alert_bbl" style="display: none;">
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diff --git a/files/pt-pt/tools/performance/waterfall/index.html b/files/pt-pt/tools/performance/waterfall/index.html
index dd58c2d7d5..ba31aa2693 100644
--- a/files/pt-pt/tools/performance/waterfall/index.html
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@@ -483,9 +483,9 @@ function calculatePrimes() {
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -497,7 +497,7 @@ function calculatePrimes() {
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/tools/settings/index.html b/files/pt-pt/tools/settings/index.html
index 88d25ff615..2f76fb3b10 100644
--- a/files/pt-pt/tools/settings/index.html
+++ b/files/pt-pt/tools/settings/index.html
@@ -164,9 +164,9 @@ original_slug: Tools/Configurações
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
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@@ -178,7 +178,7 @@ original_slug: Tools/Configurações
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/tools/tools_toolbox/index.html b/files/pt-pt/tools/tools_toolbox/index.html
index 9376aefb14..f1fd212ad2 100644
--- a/files/pt-pt/tools/tools_toolbox/index.html
+++ b/files/pt-pt/tools/tools_toolbox/index.html
@@ -100,9 +100,9 @@ translation_of: Tools/Tools_Toolbox
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; display: none; opacity: 1;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -114,7 +114,7 @@ translation_of: Tools/Tools_Toolbox
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/tools/web_console/console_messages/index.html b/files/pt-pt/tools/web_console/console_messages/index.html
index c311345d46..c4e251e0ed 100644
--- a/files/pt-pt/tools/web_console/console_messages/index.html
+++ b/files/pt-pt/tools/web_console/console_messages/index.html
@@ -394,9 +394,9 @@ doStuff();</pre>
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
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@@ -408,7 +408,7 @@ doStuff();</pre>
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/canvas_api/index.html b/files/pt-pt/web/api/canvas_api/index.html
index 379440ef0c..2118f051c5 100644
--- a/files/pt-pt/web/api/canvas_api/index.html
+++ b/files/pt-pt/web/api/canvas_api/index.html
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
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@@ -181,7 +181,7 @@ window.addEventListener('load', drawCanvas);
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
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 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/document_object_model/index.html b/files/pt-pt/web/api/document_object_model/index.html
index 87bcf85174..eecf95b04f 100644
--- a/files/pt-pt/web/api/document_object_model/index.html
+++ b/files/pt-pt/web/api/document_object_model/index.html
@@ -425,9 +425,9 @@ original_slug: DOM/DOM_Reference
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
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@@ -439,7 +439,7 @@ original_slug: DOM/DOM_Reference
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 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/geolocation/index.html b/files/pt-pt/web/api/geolocation/index.html
index 39a22949bb..3e3387d0b4 100644
--- a/files/pt-pt/web/api/geolocation/index.html
+++ b/files/pt-pt/web/api/geolocation/index.html
@@ -142,9 +142,9 @@ translation_of: Web/API/Geolocation
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: 0% 0% repeat scroll rgba(0, 0, 0, 0); display: none; opacity: 1; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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-<div id="SL_shadow_translator" style="display: none;">
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@@ -156,7 +156,7 @@ translation_of: Web/API/Geolocation
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 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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-<div id="SL_shadow_translator" style="display: none;">
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@@ -145,7 +145,7 @@ original_slug: Web/API/API_transmissoes_multimedia
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-<div id="SL_alert_bbl" style="display: none;">
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 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/sharedworker/index.html b/files/pt-pt/web/api/sharedworker/index.html
index 5f7babaa6f..bf476434fb 100644
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-<div id="SL_shadow_translation_result2" style="display: none;"></div>
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-<div id="SL_shadow_translator" style="display: none;">
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@@ -133,7 +133,7 @@ myWorker.port.onmessage = function(e) {
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-<div id="SL_alert_bbl" style="display: none;">
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+++ b/files/pt-pt/web/api/web_workers_api/functions_and_classes_available_to_workers/index.html
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
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@@ -380,7 +380,7 @@ translation_of: Web/API/Web_Workers_API/Functions_and_classes_available_to_worke
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 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
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 <div id="SL_alert_cont"> </div>
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-<div id="SL_alert_bbl" style="display: none;">
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 <div id="SL_alert_cont"> </div>
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    </td>
    <td class="SL_td">
-    <div id="SL_bbl_font_patch" style="display: none;"> </div>
+    <div id="SL_bbl_font_patch" class="hidden"> </div>
 
     <div class="SL_font_on" id="SL_bbl_font" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;" title="Tamanho da fonte"> </div>
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@@ -1070,7 +1070,7 @@ onmessage = function(event) {
 
 <div id="SL_player2" style="display: none; height: 0px;"> </div>
 
-<div id="SL_alert100" style="display: none;">A função de fala é limitada a 200 caracteres</div>
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diff --git a/files/pt-pt/web/api/webgl_api/constants/index.html b/files/pt-pt/web/api/webgl_api/constants/index.html
index 28bbc9b265..2ebc509bcd 100644
--- a/files/pt-pt/web/api/webgl_api/constants/index.html
+++ b/files/pt-pt/web/api/webgl_api/constants/index.html
@@ -3943,9 +3943,9 @@ var vendor = gl.getParameter(debugInfo.UNMASKED_VENDOR_WEBGL);</pre>
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -3957,7 +3957,7 @@ var vendor = gl.getParameter(debugInfo.UNMASKED_VENDOR_WEBGL);</pre>
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/webgl_api/data/index.html b/files/pt-pt/web/api/webgl_api/data/index.html
index 2b86ccb293..b085643358 100644
--- a/files/pt-pt/web/api/webgl_api/data/index.html
+++ b/files/pt-pt/web/api/webgl_api/data/index.html
@@ -57,9 +57,9 @@ original_slug: Web/API/WebGL_API/Dados
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 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: none; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
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 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -71,7 +71,7 @@ original_slug: Web/API/WebGL_API/Dados
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/webgl_api/types/index.html b/files/pt-pt/web/api/webgl_api/types/index.html
index f70ff586bf..1228b2a17a 100644
--- a/files/pt-pt/web/api/webgl_api/types/index.html
+++ b/files/pt-pt/web/api/webgl_api/types/index.html
@@ -166,9 +166,9 @@ original_slug: Web/API/WebGL_API/Tipos
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 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 1; display: none; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
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 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -180,7 +180,7 @@ original_slug: Web/API/WebGL_API/Tipos
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/webgl_api/using_extensions/index.html b/files/pt-pt/web/api/webgl_api/using_extensions/index.html
index ea07fcd613..30d87afbcd 100644
--- a/files/pt-pt/web/api/webgl_api/using_extensions/index.html
+++ b/files/pt-pt/web/api/webgl_api/using_extensions/index.html
@@ -642,9 +642,9 @@ original_slug: Web/API/WebGL_API/Utilizar_Extensões
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 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 1; display: none; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -656,7 +656,7 @@ original_slug: Web/API/WebGL_API/Utilizar_Extensões
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/webglrenderingcontext/index.html b/files/pt-pt/web/api/webglrenderingcontext/index.html
index 7d9b4ef24e..e1558755ca 100644
--- a/files/pt-pt/web/api/webglrenderingcontext/index.html
+++ b/files/pt-pt/web/api/webglrenderingcontext/index.html
@@ -367,9 +367,9 @@ var gl = canvas.getContext('webgl');
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 1; display: none; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -381,7 +381,7 @@ var gl = canvas.getContext('webgl');
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/webrtc_api/index.html b/files/pt-pt/web/api/webrtc_api/index.html
index 4597aadd44..a9bc4acd29 100644
--- a/files/pt-pt/web/api/webrtc_api/index.html
+++ b/files/pt-pt/web/api/webrtc_api/index.html
@@ -207,9 +207,9 @@ original_slug: Web/API/API_WebRTC
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 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 1; display: none; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
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 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -221,7 +221,7 @@ original_slug: Web/API/API_WebRTC
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/window/open/index.html b/files/pt-pt/web/api/window/open/index.html
index bb64902182..0638235527 100644
--- a/files/pt-pt/web/api/window/open/index.html
+++ b/files/pt-pt/web/api/window/open/index.html
@@ -667,9 +667,9 @@ window.open("map.php", "BiggerMap");</pre>
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -681,7 +681,7 @@ window.open("map.php", "BiggerMap");</pre>
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/window/postmessage/index.html b/files/pt-pt/web/api/window/postmessage/index.html
index 50e5c91a5d..2787caaa32 100644
--- a/files/pt-pt/web/api/window/postmessage/index.html
+++ b/files/pt-pt/web/api/window/postmessage/index.html
@@ -256,9 +256,9 @@ window.addEventListener("message", receiveMessage, false);
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: block; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -270,7 +270,7 @@ window.addEventListener("message", receiveMessage, false);
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/api/worker/index.html b/files/pt-pt/web/api/worker/index.html
index cdeee23a8a..ee53553220 100644
--- a/files/pt-pt/web/api/worker/index.html
+++ b/files/pt-pt/web/api/worker/index.html
@@ -193,9 +193,9 @@ first.onchange = function() {
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 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: block; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -207,7 +207,7 @@ first.onchange = function() {
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/css/css_colors/color_picker_tool/index.html b/files/pt-pt/web/css/css_colors/color_picker_tool/index.html
index 8772d20f06..853610e804 100644
--- a/files/pt-pt/web/css/css_colors/color_picker_tool/index.html
+++ b/files/pt-pt/web/css/css_colors/color_picker_tool/index.html
@@ -9,7 +9,7 @@ tags:
 translation_of: Web/CSS/CSS_Colors/Color_picker_tool
 original_slug: Web/CSS/CSS_Colors/Ferramenta_selecao_cor
 ---
-<div style="display: none;">
+<div class="hidden">
 <h2 id="ColorPicker_Tool" name="ColorPicker_Tool">ColorPicker tool</h2>
 
 <h3 id="HTML">HTML</h3>
diff --git a/files/pt-pt/web/css/display/index.html b/files/pt-pt/web/css/display/index.html
index 43db53135e..db3e3150d1 100644
--- a/files/pt-pt/web/css/display/index.html
+++ b/files/pt-pt/web/css/display/index.html
@@ -626,9 +626,9 @@ display: unset;
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -640,7 +640,7 @@ display: unset;
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/events/index.html b/files/pt-pt/web/events/index.html
index c778cec718..191f5abb6f 100644
--- a/files/pt-pt/web/events/index.html
+++ b/files/pt-pt/web/events/index.html
@@ -3000,9 +3000,9 @@ original_slug: Web/Eventos
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: 0% 0% repeat scroll rgba(0, 0, 0, 0); opacity: 1; display: none; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -3014,7 +3014,7 @@ original_slug: Web/Eventos
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/guide/events/index.html b/files/pt-pt/web/guide/events/index.html
index 7d55886a4e..88b9c2f2c8 100644
--- a/files/pt-pt/web/guide/events/index.html
+++ b/files/pt-pt/web/guide/events/index.html
@@ -53,9 +53,9 @@ original_slug: Web/Guide/Eventos
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; display: none; opacity: 1;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
diff --git a/files/pt-pt/web/html/applying_color/index.html b/files/pt-pt/web/html/applying_color/index.html
index fd91bc88b8..75c0e0f32b 100644
--- a/files/pt-pt/web/html/applying_color/index.html
+++ b/files/pt-pt/web/html/applying_color/index.html
@@ -503,7 +503,7 @@ colorPicker.addEventListener("change", function(event) {
 
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-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -515,7 +515,7 @@ colorPicker.addEventListener("change", function(event) {
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/html/link_types/index.html b/files/pt-pt/web/html/link_types/index.html
index a91d1c85a0..7d26dd44bf 100644
--- a/files/pt-pt/web/html/link_types/index.html
+++ b/files/pt-pt/web/html/link_types/index.html
@@ -532,9 +532,9 @@ original_slug: Web/HTML/Tipos_de_hiperligacao
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: block; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -546,7 +546,7 @@ original_slug: Web/HTML/Tipos_de_hiperligacao
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/javascript/reference/statements/throw/index.html b/files/pt-pt/web/javascript/reference/statements/throw/index.html
index ffea8a688e..59a0e32938 100644
--- a/files/pt-pt/web/javascript/reference/statements/throw/index.html
+++ b/files/pt-pt/web/javascript/reference/statements/throw/index.html
@@ -195,9 +195,9 @@ e = verifyZipCode('95060 1234');  // returns 95060 1234
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-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -209,7 +209,7 @@ e = verifyZipCode('95060 1234');  // returns 95060 1234
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/security/insecure_passwords/index.html b/files/pt-pt/web/security/insecure_passwords/index.html
index e559b838d8..31344bf0ac 100644
--- a/files/pt-pt/web/security/insecure_passwords/index.html
+++ b/files/pt-pt/web/security/insecure_passwords/index.html
@@ -77,9 +77,9 @@ original_slug: Web/Seguranca/Palavras-passe_inseguras
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; display: none; opacity: 1; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -91,7 +91,7 @@ original_slug: Web/Seguranca/Palavras-passe_inseguras
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/security/secure_contexts/index.html b/files/pt-pt/web/security/secure_contexts/index.html
index d2de69988c..23ad21540d 100644
--- a/files/pt-pt/web/security/secure_contexts/index.html
+++ b/files/pt-pt/web/security/secure_contexts/index.html
@@ -125,7 +125,7 @@ translation_of: Web/Security/Secure_Contexts
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: block; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
 <div id="SL_shadow_translator">
 <div id="SL_planshet">
diff --git a/files/pt-pt/web/svg/applying_svg_effects_to_html_content/index.html b/files/pt-pt/web/svg/applying_svg_effects_to_html_content/index.html
index 6b97eae267..ad5df9bdda 100644
--- a/files/pt-pt/web/svg/applying_svg_effects_to_html_content/index.html
+++ b/files/pt-pt/web/svg/applying_svg_effects_to_html_content/index.html
@@ -180,7 +180,7 @@ pre.target:hover { filter:url(#f3); }
 
 <p>{{EmbedLiveSample('Example_Filtering', 650, 200)}}</p>
 
-<p style="display: none;"><a class="button liveSample" href="/files/3329/filterdemo.xhtml">View this example live</a></p>
+<p class="hidden"><a class="button liveSample" href="/files/3329/filterdemo.xhtml">View this example live</a></p>
 
 <h3 id="Example_Blurred_Text">Example: Blurred Text</h3>
 
@@ -225,7 +225,7 @@ pre.target:hover { filter:url(#f3); }
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: block; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
 <div id="SL_shadow_translator">
 <div id="SL_planshet">
diff --git a/files/pt-pt/web/svg/namespaces_crash_course/example/index.html b/files/pt-pt/web/svg/namespaces_crash_course/example/index.html
index 9a319f0673..7650c9e2fb 100644
--- a/files/pt-pt/web/svg/namespaces_crash_course/example/index.html
+++ b/files/pt-pt/web/svg/namespaces_crash_course/example/index.html
@@ -318,9 +318,9 @@ cy='150' r='7' fill='#0000ff' fill-opacity='0.5'/&gt;
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: block; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -332,7 +332,7 @@ cy='150' r='7' fill='#0000ff' fill-opacity='0.5'/&gt;
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/svg/namespaces_crash_course/index.html b/files/pt-pt/web/svg/namespaces_crash_course/index.html
index 54a6d077b4..25941a6733 100644
--- a/files/pt-pt/web/svg/namespaces_crash_course/index.html
+++ b/files/pt-pt/web/svg/namespaces_crash_course/index.html
@@ -189,9 +189,9 @@ image.setAttributeNS(XLink_NS, 'xlink:href', 'flower.png');
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 1; display: none; left: -8px; top: -25px;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -203,7 +203,7 @@ image.setAttributeNS(XLink_NS, 'xlink:href', 'flower.png');
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/svg/tutorial/svg_in_html_introduction/index.html b/files/pt-pt/web/svg/tutorial/svg_in_html_introduction/index.html
index d8cfd63791..c1c37212b9 100644
--- a/files/pt-pt/web/svg/tutorial/svg_in_html_introduction/index.html
+++ b/files/pt-pt/web/svg/tutorial/svg_in_html_introduction/index.html
@@ -103,9 +103,9 @@ img.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href", "move.png");
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: none; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -117,7 +117,7 @@ img.setAttributeNS("http://www.w3.org/1999/xlink", "xlink:href", "move.png");
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>
diff --git a/files/pt-pt/web/xml/xml_introduction/index.html b/files/pt-pt/web/xml/xml_introduction/index.html
index b397f39c4b..ff94cb49c2 100644
--- a/files/pt-pt/web/xml/xml_introduction/index.html
+++ b/files/pt-pt/web/xml/xml_introduction/index.html
@@ -128,9 +128,9 @@ original_slug: Web/XML/Introducao_a_XML
 <div id="SL_balloon_obj" style="display: block;">
 <div class="SL_ImTranslatorLogo" id="SL_button" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%; opacity: 0; display: none; left: -8px; top: -25px; transition: visibility 2s ease 0s, opacity 2s linear 0s;"> </div>
 
-<div id="SL_shadow_translation_result2" style="display: none;"> </div>
+<div id="SL_shadow_translation_result2" class="hidden"> </div>
 
-<div id="SL_shadow_translator" style="display: none;">
+<div id="SL_shadow_translator" class="hidden">
 <div id="SL_planshet">
 <div id="SL_arrow_up" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
@@ -142,7 +142,7 @@ original_slug: Web/XML/Introducao_a_XML
 <div class="SL_BL_LABLE_ON" id="SL_P2" title="Translator">T</div>
 </div>
 
-<div id="SL_alert_bbl" style="display: none;">
+<div id="SL_alert_bbl" class="hidden">
 <div id="SLHKclose" style="background: rgba(0, 0, 0, 0)  repeat scroll 0% 0%;"> </div>
 
 <div id="SL_alert_cont"> </div>