diff --git a/phpBB/assets/javascript/core.js b/phpBB/assets/javascript/core.js
index 36e881f5fd..6285a16734 100644
--- a/phpBB/assets/javascript/core.js
+++ b/phpBB/assets/javascript/core.js
@@ -27,7 +27,10 @@ phpbb.isTouch = (window && typeof window.ontouchstart !== 'undefined');
  */
 phpbb.loadingIndicator = function() {
 	if (!$loadingIndicator) {
-		$loadingIndicator = $('<div />', { id: 'loading_indicator' });
+		$loadingIndicator = $('<div />', { 
+			id: 'loading_indicator', 
+			class: 'loading_indicator', 
+		});
 		$loadingIndicator.appendTo('#page-footer');
 	}
 
diff --git a/phpBB/styles/prosilver/template/mcp_header.html b/phpBB/styles/prosilver/template/mcp_header.html
index 69239887e3..424bb36858 100644
--- a/phpBB/styles/prosilver/template/mcp_header.html
+++ b/phpBB/styles/prosilver/template/mcp_header.html
@@ -21,14 +21,14 @@
 
 	<div style="width: 100%;">
 
-	<div id="cp-menu">
-		<div id="navigation" role="navigation">
+	<div id="cp-menu" class="cp-menu">
+		<div id="navigation" class="navigation" role="navigation">
 			<ul>
 			<!-- BEGIN l_block1 -->
 			<!-- IF l_block1.S_SELECTED -->
 				<!-- BEGIN l_block2 -->
 				<!-- IF l_block1.l_block2.S_SELECTED -->
-				<li id="active-subsection"><a href="{l_block1.l_block2.U_TITLE}"><span>{l_block1.l_block2.L_TITLE}<!-- IF l_block1.l_block2.ADD_ITEM --> ({l_block1.l_block2.ADD_ITEM})<!-- ENDIF --></span></a></li>
+				<li id="active-subsection" class="active-subsection"><a href="{l_block1.l_block2.U_TITLE}"><span>{l_block1.l_block2.L_TITLE}<!-- IF l_block1.l_block2.ADD_ITEM --> ({l_block1.l_block2.ADD_ITEM})<!-- ENDIF --></span></a></li>
 				<!-- ELSE -->
 				<li><a href="{l_block1.l_block2.U_TITLE}"><span>{l_block1.l_block2.L_TITLE}<!-- IF l_block1.l_block2.ADD_ITEM --> ({l_block1.l_block2.ADD_ITEM})<!-- ENDIF --></span></a></li>
 				<!-- ENDIF -->
@@ -39,7 +39,7 @@
 		</div>
 	</div>
 
-	<div id="cp-main" class="mcp-main panel-container">
+	<div id="cp-main" class="cp-main mcp-main panel-container">
 		<!-- IF MESSAGE -->
 		<div class="content">
 			<h2 class="message-title">{L_MESSAGE}</h2>
diff --git a/phpBB/styles/prosilver/template/mcp_post.html b/phpBB/styles/prosilver/template/mcp_post.html
index 81d1be795e..0354cdd3ca 100644
--- a/phpBB/styles/prosilver/template/mcp_post.html
+++ b/phpBB/styles/prosilver/template/mcp_post.html
@@ -106,7 +106,7 @@
 			</p>
 		<!-- ENDIF -->
 
-		<div class="content" id="post_details">
+		<div id="post_details" class="content post_details">
 			{POST_PREVIEW}
 		</div>
 
diff --git a/phpBB/styles/prosilver/template/mcp_topic.html b/phpBB/styles/prosilver/template/mcp_topic.html
index c21b676370..5a6922858a 100644
--- a/phpBB/styles/prosilver/template/mcp_topic.html
+++ b/phpBB/styles/prosilver/template/mcp_topic.html
@@ -11,7 +11,7 @@
 	<!-- DEFINE $SHOW_PANEL = 'display-panel' -->
 <!-- ENDIF -->
 
-<div id="minitabs" class="sub-panels" data-show-panel="{$SHOW_PANEL}" role="tablist">
+<div id="minitabs" class="minitabs sub-panels" data-show-panel="{$SHOW_PANEL}" role="tablist">
 	<ul>
 		<li id="display-panel-tab" class="tab<!-- IF not S_MERGE_VIEW --> activetab<!-- ENDIF -->">
 			<a href="#minitabs" data-subpanel="display-panel" role="tab" aria-controls="display-panel">{L_DISPLAY_OPTIONS}</a>
@@ -87,12 +87,12 @@
 <div class="panel">
 	<div class="inner">
 
-	<h3 id="review">
+	<h3 id="review" class="review">
 		<span class="right-box"><a href="#review" onclick="viewableArea(getElementById('topicreview'), true); var rev_text = getElementById('review').getElementsByTagName('a').item(0).firstChild; if (rev_text.data == '{LA_EXPAND_VIEW}'){rev_text.data = '{LA_COLLAPSE_VIEW}'; } else if (rev_text.data == '{LA_COLLAPSE_VIEW}'){rev_text.data = '{LA_EXPAND_VIEW}'};">{L_EXPAND_VIEW}</a></span>
 		{L_TOPIC_REVIEW}{L_COLON} <!-- EVENT mcp_topic_topic_title_before -->{TOPIC_TITLE}<!-- EVENT mcp_topic_topic_title_after -->
 	</h3>
 
-	<div id="topicreview">
+	<div id="topicreview" class="topicreview">
 		<!-- BEGIN postrow -->
 		<div class="post <!-- IF postrow.S_ROW_COUNT is odd -->bg1<!-- ELSE -->bg2<!-- ENDIF -->">
 			<div class="inner">
diff --git a/phpBB/styles/prosilver/template/memberlist_body.html b/phpBB/styles/prosilver/template/memberlist_body.html
index 3d61b7656f..20f46af90d 100644
--- a/phpBB/styles/prosilver/template/memberlist_body.html
+++ b/phpBB/styles/prosilver/template/memberlist_body.html
@@ -48,7 +48,7 @@
 	<div class="forumbg forumbg-table">
 		<div class="inner">
 
-		<table class="table1" id="memberlist">
+		<table class="table1 memberlist" id="memberlist">
 		<thead>
 		<tr>
 			<th class="name" data-dfn="{L_RANK}{L_COMMA_SEPARATOR}<!-- IF S_SHOW_GROUP and .memberrow -->{L_GROUP_LEADER}<!-- ELSE -->{L_USERNAME}<!-- ENDIF -->"><span class="rank-img"><a href="{U_SORT_RANK}">{L_RANK}</a></span><a href="{U_SORT_USERNAME}"><!-- IF S_SHOW_GROUP and .memberrow -->{L_GROUP_LEADER}<!-- ELSE -->{L_USERNAME}<!-- ENDIF --></a></th>
diff --git a/phpBB/styles/prosilver/template/navbar_header.html b/phpBB/styles/prosilver/template/navbar_header.html
index faf48e0b05..b2dd87d1c8 100644
--- a/phpBB/styles/prosilver/template/navbar_header.html
+++ b/phpBB/styles/prosilver/template/navbar_header.html
@@ -3,7 +3,7 @@
 
 	<ul id="nav-main" class="linklist bulletin" role="menubar">
 
-		<li id="quick-links" class="small-icon responsive-menu dropdown-container<!-- IF not S_DISPLAY_QUICK_LINKS and not S_DISPLAY_SEARCH --> hidden<!-- ENDIF -->" data-skip-responsive="true">
+		<li id="quick-links" class="quick-links small-icon responsive-menu dropdown-container<!-- IF not S_DISPLAY_QUICK_LINKS and not S_DISPLAY_SEARCH --> hidden<!-- ENDIF -->" data-skip-responsive="true">
 			<a href="#" class="responsive-menu-link dropdown-trigger">{L_QUICK_LINKS}</a>
 			<div class="dropdown hidden">
 				<div class="pointer"><div class="pointer-inner"></div></div>
diff --git a/phpBB/styles/prosilver/template/overall_footer.html b/phpBB/styles/prosilver/template/overall_footer.html
index ecba72f6f4..a90aad15f2 100644
--- a/phpBB/styles/prosilver/template/overall_footer.html
+++ b/phpBB/styles/prosilver/template/overall_footer.html
@@ -3,7 +3,7 @@
 
 <!-- EVENT overall_footer_page_body_after -->
 
-<div id="page-footer" role="contentinfo">
+<div id="page-footer" class="page-footer" role="contentinfo">
 	<!-- INCLUDE navbar_footer.html -->
 
 	<div class="copyright">
@@ -15,8 +15,8 @@
 		<!-- IF U_ACP --><br /><strong><a href="{U_ACP}">{L_ACP}</a></strong><!-- ENDIF -->
 	</div>
 
-	<div id="darkenwrapper" data-ajax-error-title="{L_AJAX_ERROR_TITLE}" data-ajax-error-text="{L_AJAX_ERROR_TEXT}" data-ajax-error-text-abort="{L_AJAX_ERROR_TEXT_ABORT}" data-ajax-error-text-timeout="{L_AJAX_ERROR_TEXT_TIMEOUT}" data-ajax-error-text-parsererror="{L_AJAX_ERROR_TEXT_PARSERERROR}">
-		<div id="darken">&nbsp;</div>
+	<div id="darkenwrapper" class="darkenwrapper" data-ajax-error-title="{L_AJAX_ERROR_TITLE}" data-ajax-error-text="{L_AJAX_ERROR_TEXT}" data-ajax-error-text-abort="{L_AJAX_ERROR_TEXT_ABORT}" data-ajax-error-text-timeout="{L_AJAX_ERROR_TEXT_TIMEOUT}" data-ajax-error-text-parsererror="{L_AJAX_ERROR_TEXT_PARSERERROR}">
+		<div id="darken" class="darken">&nbsp;</div>
 	</div>
 
 	<div id="phpbb_alert" class="phpbb_alert" data-l-err="{L_ERROR}" data-l-timeout-processing-req="{L_TIMEOUT_PROCESSING_REQ}">
diff --git a/phpBB/styles/prosilver/template/overall_header.html b/phpBB/styles/prosilver/template/overall_header.html
index 40e735c5c2..33d2441035 100644
--- a/phpBB/styles/prosilver/template/overall_header.html
+++ b/phpBB/styles/prosilver/template/overall_header.html
@@ -71,13 +71,13 @@
 
 <!-- EVENT overall_header_body_before -->
 
-<div id="wrap">
-	<a id="top" class="anchor" accesskey="t"></a>
+<div id="wrap" class="wrap">
+	<a id="top" class="top-anchor" accesskey="t"></a>
 	<div id="page-header">
 		<div class="headerbar" role="banner">
 			<div class="inner">
 
-			<div id="site-description">
+			<div id="site-description" class="site-description">
 				<a id="logo" class="logo" href="<!-- IF U_SITE_HOME -->{U_SITE_HOME}<!-- ELSE -->{U_INDEX}<!-- ENDIF -->" title="<!-- IF U_SITE_HOME -->{L_SITE_HOME}<!-- ELSE -->{L_INDEX}<!-- ENDIF -->">{SITE_LOGO_IMG}</a>
 				<h1>{SITENAME}</h1>
 				<p>{SITE_DESCRIPTION}</p>
@@ -107,7 +107,7 @@
 	<!-- EVENT overall_header_page_body_before -->
 
 	<a id="start_here" class="anchor"></a>
-	<div id="page-body" role="main">
+	<div id="page-body" class="page-body" role="main">
 		<!-- IF S_BOARD_DISABLED and S_USER_LOGGED_IN and (U_MCP or U_ACP) -->
 		<div id="information" class="rules">
 			<div class="inner">
diff --git a/phpBB/styles/prosilver/template/posting_attach_body.html b/phpBB/styles/prosilver/template/posting_attach_body.html
index 81b2c2bf41..81e3186de1 100644
--- a/phpBB/styles/prosilver/template/posting_attach_body.html
+++ b/phpBB/styles/prosilver/template/posting_attach_body.html
@@ -17,11 +17,11 @@
 	</dl>
 	</fieldset>
 
-	<div id="attach-panel-multi">
+	<div id="attach-panel-multi" class="attach-panel-multi">
 		<input type="button" class="button2" value="{L_PLUPLOAD_ADD_FILES}" id="add_files" />
 	</div>
 
-	<div class="panel<!-- IF not .attach_row --> hidden<!-- ENDIF -->" id="file-list-container">
+	<div class="panel<!-- IF not .attach_row --> hidden<!-- ENDIF --> file-list-container" id="file-list-container">
 		<div class="inner">
 			<table class="table1 zebra-list fixed-width-table">
 				<thead>
@@ -32,7 +32,7 @@
 						<th class="attach-status">{L_PLUPLOAD_STATUS}</th>
 					</tr>
 				</thead>
-				<tbody class="responsive-skip-empty" id="file-list">
+				<tbody class="responsive-skip-empty file-list" id="file-list">
 					<tr class="attach-row" id="attach-row-tpl">
 							<td class="attach-name">
 								<span class="file-name ellipsis-text"></span>
diff --git a/phpBB/styles/prosilver/template/posting_buttons.html b/phpBB/styles/prosilver/template/posting_buttons.html
index 1555b12369..e357a56494 100644
--- a/phpBB/styles/prosilver/template/posting_buttons.html
+++ b/phpBB/styles/prosilver/template/posting_buttons.html
@@ -55,12 +55,12 @@
 <div id="colour_palette" style="display: none;">
 	<dl style="clear: left;">
 		<dt><label>{L_FONT_COLOR}{L_COLON}</label></dt>
-		<dd id="color_palette_placeholder" data-orientation="h" data-height="12" data-width="15" data-bbcode="true"></dd>
+		<dd id="color_palette_placeholder" class="color_palette_placeholder" data-orientation="h" data-height="12" data-width="15" data-bbcode="true"></dd>
 	</dl>
 </div>
 
 <!-- EVENT posting_editor_buttons_before -->
-<div id="format-buttons">
+<div id="format-buttons" class="format-buttons">
 	<input type="button" class="button2 bbcode-b" accesskey="b" name="addbbcode0" value=" B " style="font-weight:bold; width: 30px" onclick="bbstyle(0)" title="{L_BBCODE_B_HELP}" />
 	<input type="button" class="button2 bbcode-i" accesskey="i" name="addbbcode2" value=" i " style="font-style:italic; width: 30px" onclick="bbstyle(2)" title="{L_BBCODE_I_HELP}" />
 	<input type="button" class="button2 bbcode-u" accesskey="u" name="addbbcode4" value=" u " style="text-decoration: underline; width: 30px" onclick="bbstyle(4)" title="{L_BBCODE_U_HELP}" />
diff --git a/phpBB/styles/prosilver/template/posting_editor.html b/phpBB/styles/prosilver/template/posting_editor.html
index 484ca341c4..60d7b6c428 100644
--- a/phpBB/styles/prosilver/template/posting_editor.html
+++ b/phpBB/styles/prosilver/template/posting_editor.html
@@ -35,7 +35,7 @@
 
 	<!-- INCLUDE posting_buttons.html -->
 
-	<div id="smiley-box">
+	<div id="smiley-box" class="smiley-box">
 		<!-- EVENT posting_editor_smilies_before -->	
 		<!-- IF S_SMILIES_ALLOWED and .smiley -->
 			<strong>{L_SMILIES}</strong><br />
@@ -69,7 +69,7 @@
 
 	<!-- EVENT posting_editor_message_before -->
 
-	<div id="message-box">
+	<div id="message-box" class="message-box">
 		<textarea <!-- IF S_UCP_ACTION and not S_PRIVMSGS and not S_EDIT_DRAFT -->name="signature" id="signature" style="height: 9em;"<!-- ELSE -->name="message" id="message"<!-- ENDIF --> rows="15" cols="76" tabindex="4" onselect="storeCaret(this);" onclick="storeCaret(this);" onkeyup="storeCaret(this);" onfocus="initInsertions();" class="inputbox">{MESSAGE}{DRAFT_MESSAGE}{SIGNATURE}</textarea>
 	</div>
 
@@ -102,13 +102,13 @@
 	<!-- ENDIF -->
 
 	<!-- IF not S_PRIVMSGS and not S_SHOW_DRAFTS and not $SIG_EDIT eq 1 -->
-		<div id="tabs" class="sub-panels" data-show-panel="<!-- IF SHOW_PANEL -->{SHOW_PANEL}<!-- ELSE -->options-panel<!-- ENDIF -->" role="tablist">
+		<div id="tabs" class="tabs sub-panels" data-show-panel="<!-- IF SHOW_PANEL -->{SHOW_PANEL}<!-- ELSE -->options-panel<!-- ENDIF -->" role="tablist">
 			<ul>
 				<li id="options-panel-tab" class="tab activetab"><a href="#tabs" data-subpanel="options-panel" role="tab" aria-controls="options-panel"><span>{L_OPTIONS}</span></a></li>
 				<!-- IF S_SHOW_ATTACH_BOX -->
 					<li id="attach-panel-tab" class="tab">
 						<a href="#tabs" data-subpanel="attach-panel" role="tab" aria-controls="attach-panel">
-							{L_ATTACHMENTS} <strong id="file-total-progress"><strong id="file-total-progress-bar"></strong></strong>
+							{L_ATTACHMENTS} <strong id="file-total-progress" class="file-total-progress"><strong id="file-total-progress-bar" class="file-total-progress-bar"></strong></strong>
 						</a>
 					</li>
 				<!-- ENDIF -->
diff --git a/phpBB/styles/prosilver/template/posting_topic_review.html b/phpBB/styles/prosilver/template/posting_topic_review.html
index fc7d0a2c63..9016e40ded 100644
--- a/phpBB/styles/prosilver/template/posting_topic_review.html
+++ b/phpBB/styles/prosilver/template/posting_topic_review.html
@@ -1,10 +1,10 @@
 
-<h3 id="review">
+<h3 id="review" class="review">
 	<span class="right-box"><a href="#review" onclick="viewableArea(getElementById('topicreview'), true); var rev_text = getElementById('review').getElementsByTagName('a').item(0).firstChild; if (rev_text.data == '{LA_EXPAND_VIEW}'){rev_text.data = '{LA_COLLAPSE_VIEW}'; } else if (rev_text.data == '{LA_COLLAPSE_VIEW}'){rev_text.data = '{LA_EXPAND_VIEW}'};">{L_EXPAND_VIEW}</a></span>
 	{L_TOPIC_REVIEW}{L_COLON} {TOPIC_TITLE}
 </h3>
 
-<div id="topicreview">
+<div id="topicreview" class="topicreview">
 <script type="text/javascript">
 // <![CDATA[
 	bbcodeEnabled = {S_BBCODE_ALLOWED};
diff --git a/phpBB/styles/prosilver/template/quickreply_editor.html b/phpBB/styles/prosilver/template/quickreply_editor.html
index 6a8846626e..c9ae52477e 100644
--- a/phpBB/styles/prosilver/template/quickreply_editor.html
+++ b/phpBB/styles/prosilver/template/quickreply_editor.html
@@ -9,7 +9,7 @@
 						<dd><input type="text" name="subject" id="subject" size="45" maxlength="124" tabindex="2" value="{SUBJECT}" class="inputbox autowidth" /></dd>
 					</dl>
 				<!-- EVENT quickreply_editor_message_before -->
-				<div id="message-box">
+				<div id="message-box" class="message-box">
 					<textarea style="height: 9em;" name="message" rows="7" cols="76" tabindex="3" class="inputbox"></textarea>
 				</div>
 				<!-- EVENT quickreply_editor_message_after -->
diff --git a/phpBB/styles/prosilver/template/simple_footer.html b/phpBB/styles/prosilver/template/simple_footer.html
index 123f8992f2..fd7bf0c6bd 100644
--- a/phpBB/styles/prosilver/template/simple_footer.html
+++ b/phpBB/styles/prosilver/template/simple_footer.html
@@ -5,10 +5,10 @@
 		<!-- IF DEBUG_OUTPUT --><br />{DEBUG_OUTPUT}<!-- ENDIF -->
 	</div>
 
-	<div id="darkenwrapper" data-ajax-error-title="{L_AJAX_ERROR_TITLE}" data-ajax-error-text="{L_AJAX_ERROR_TEXT}" data-ajax-error-text-abort="{L_AJAX_ERROR_TEXT_ABORT}" data-ajax-error-text-timeout="{L_AJAX_ERROR_TEXT_TIMEOUT}" data-ajax-error-text-parsererror="{L_AJAX_ERROR_TEXT_PARSERERROR}">
-		<div id="darken">&nbsp;</div>
+	<div id="darkenwrapper" class="darkenwrapper" data-ajax-error-title="{L_AJAX_ERROR_TITLE}" data-ajax-error-text="{L_AJAX_ERROR_TEXT}" data-ajax-error-text-abort="{L_AJAX_ERROR_TEXT_ABORT}" data-ajax-error-text-timeout="{L_AJAX_ERROR_TEXT_TIMEOUT}" data-ajax-error-text-parsererror="{L_AJAX_ERROR_TEXT_PARSERERROR}">
+		<div id="darken" class="darken">&nbsp;</div>
 	</div>
-	<div id="loading_indicator"></div>
+	<div id="loading_indicator" class="loading_indicator"></div>
 
 	<div id="phpbb_alert" class="phpbb_alert" data-l-err="{L_ERROR}" data-l-timeout-processing-req="{L_TIMEOUT_PROCESSING_REQ}">
 		<a href="#" class="alert_close"></a>
diff --git a/phpBB/styles/prosilver/template/simple_header.html b/phpBB/styles/prosilver/template/simple_header.html
index baa6223754..b7669d8bf0 100644
--- a/phpBB/styles/prosilver/template/simple_header.html
+++ b/phpBB/styles/prosilver/template/simple_header.html
@@ -48,6 +48,6 @@
 
 <!-- EVENT simple_header_body_before -->
 
-<div id="wrap">
-	<a id="top" class="anchor" accesskey="t"></a>
-	<div id="page-body" role="main">
+<div id="wrap" class="wrap">
+	<a id="top" class="top-anchor" accesskey="t"></a>
+	<div id="page-body" class="page-body" role="main">
diff --git a/phpBB/styles/prosilver/template/timezone_option.html b/phpBB/styles/prosilver/template/timezone_option.html
index b8be456489..728dc9487a 100644
--- a/phpBB/styles/prosilver/template/timezone_option.html
+++ b/phpBB/styles/prosilver/template/timezone_option.html
@@ -12,7 +12,7 @@
 	</dd>
 	<!-- ENDIF -->
 	<dd>
-		<select name="tz" id="timezone" class="autowidth tz_select">
+		<select name="tz" id="timezone" class="autowidth tz_select timezone">
 			<option value="">{L_SELECT_TIMEZONE}</option>
 			<!-- BEGIN timezone_select -->
 			<optgroup label="{timezone_select.LABEL}" data-tz-value="{timezone_select.VALUE}">
diff --git a/phpBB/styles/prosilver/template/ucp_avatar_options_local.html b/phpBB/styles/prosilver/template/ucp_avatar_options_local.html
index 2a0f403782..ac8d287e5a 100644
--- a/phpBB/styles/prosilver/template/ucp_avatar_options_local.html
+++ b/phpBB/styles/prosilver/template/ucp_avatar_options_local.html
@@ -6,7 +6,7 @@
 </select></label>
 <input type="submit" value="{L_GO}" name="avatar_local_go" class="button2" />
 
-<div id="gallery">
+<div id="gallery" class="gallery">
 <!-- BEGIN avatar_local_row -->
 <!-- BEGIN avatar_local_col -->
 	<label for="av-{avatar_local_row.S_ROW_COUNT}-{avatar_local_row.avatar_local_col.S_ROW_COUNT}"><img src="{avatar_local_row.avatar_local_col.AVATAR_IMAGE}" alt="" /><br />
diff --git a/phpBB/styles/prosilver/template/ucp_groups_manage.html b/phpBB/styles/prosilver/template/ucp_groups_manage.html
index 3b805c4862..b5e8eaf1e8 100644
--- a/phpBB/styles/prosilver/template/ucp_groups_manage.html
+++ b/phpBB/styles/prosilver/template/ucp_groups_manage.html
@@ -58,7 +58,7 @@
 			<input name="group_colour" type="text" id="group_colour" value="{GROUP_COLOUR}" size="6" maxlength="6" class="inputbox narrow" />
 			<span style="background-color: #{GROUP_COLOUR};">&nbsp;&nbsp;&nbsp;</span>
 			[ <a href="#" id="color_palette_toggle">{L_COLOUR_SWATCH}</a> ]
-			<div id="color_palette_placeholder" class="hidden" data-orientation="h" data-height="12" data-width="15" data-target="#group_colour"></div>
+			<div id="color_palette_placeholder" class="color_palette_placeholder hidden" data-orientation="h" data-height="12" data-width="15" data-target="#group_colour"></div>
 		</dd>
 	</dl>
 	<dl>
diff --git a/phpBB/styles/prosilver/template/ucp_header.html b/phpBB/styles/prosilver/template/ucp_header.html
index a17f145cbc..de7579999f 100644
--- a/phpBB/styles/prosilver/template/ucp_header.html
+++ b/phpBB/styles/prosilver/template/ucp_header.html
@@ -19,15 +19,15 @@
 
 	<div style="width: 100%;">
 
-	<div id="cp-menu">
-		<div id="navigation" role="navigation">
+	<div id="cp-menu" class="cp-menu">
+		<div id="navigation" class="navigation" role="navigation">
 
 		<!-- IF S_PRIVMSGS -->
 			<!-- BEGIN t_block2 -->
 				<!-- IF S_PRIVMSGS and not t_block2.S_LAST_ROW -->
 				<ul>
 					<!-- IF t_block2.S_SELECTED -->
-						<li id="active-subsection"><a href="{t_block2.U_TITLE}"><span>{t_block2.L_TITLE}</span></a></li>
+						<li id="active-subsection" class="active-subsection"><a href="{t_block2.U_TITLE}"><span>{t_block2.L_TITLE}</span></a></li>
 					<!-- ELSE -->
 						<li><a href="{t_block2.U_TITLE}"><span>{t_block2.L_TITLE}</span></a></li>
 					<!-- ENDIF -->
@@ -39,7 +39,7 @@
 			<!-- BEGIN folder -->
 				<!-- IF folder.S_FIRST_ROW --><ul><!-- ENDIF -->
 				<!-- IF folder.S_CUR_FOLDER -->
-					<li id="active-subsection"><a href="{folder.U_FOLDER}"><!-- IF folder.UNREAD_MESSAGES > 0 --><strong>{folder.FOLDER_NAME} ({folder.UNREAD_MESSAGES})</strong><!-- ELSE -->{folder.FOLDER_NAME}<!-- ENDIF --></a></li>
+					<li id="active-subsection" class="active-subsection"><a href="{folder.U_FOLDER}"><!-- IF folder.UNREAD_MESSAGES > 0 --><strong>{folder.FOLDER_NAME} ({folder.UNREAD_MESSAGES})</strong><!-- ELSE -->{folder.FOLDER_NAME}<!-- ENDIF --></a></li>
 				<!-- ELSE -->
 					<li><a href="{folder.U_FOLDER}"><span><!-- IF folder.UNREAD_MESSAGES > 0 --><strong>{folder.FOLDER_NAME} ({folder.UNREAD_MESSAGES})</strong><!-- ELSE -->{folder.FOLDER_NAME}<!-- ENDIF --></span></a></li>
 				<!-- ENDIF -->
@@ -52,7 +52,7 @@
 		<!-- BEGIN t_block2 -->
 			<!-- IF (S_PRIVMSGS and t_block2.S_LAST_ROW) or not S_PRIVMSGS -->
 				<!-- IF t_block2.S_SELECTED -->
-					<li id="active-subsection"><a href="{t_block2.U_TITLE}"><span>{t_block2.L_TITLE}</span></a></li>
+					<li id="active-subsection" class="active-subsection"><a href="{t_block2.U_TITLE}"><span>{t_block2.L_TITLE}</span></a></li>
 				<!-- ELSE -->
 					<li><a href="{t_block2.U_TITLE}"><span>{t_block2.L_TITLE}</span></a></li>
 				<!-- ENDIF -->
@@ -98,4 +98,4 @@
 
 	</div>
 
-	<div id="cp-main" class="ucp-main panel-container">
+	<div id="cp-main" class="cp main ucp-main panel-container">
diff --git a/phpBB/styles/prosilver/template/ucp_pm_history.html b/phpBB/styles/prosilver/template/ucp_pm_history.html
index f4dc1c3b34..8ecded85ca 100644
--- a/phpBB/styles/prosilver/template/ucp_pm_history.html
+++ b/phpBB/styles/prosilver/template/ucp_pm_history.html
@@ -1,11 +1,11 @@
 
-<h3 id="review">
+<h3 id="review" class="review">
 	<span class="right-box"><a href="#review" onclick="viewableArea(getElementById('topicreview'), true); var rev_text = getElementById('review').getElementsByTagName('a').item(0).firstChild; if (rev_text.data == '{LA_EXPAND_VIEW}'){rev_text.data = '{LA_COLLAPSE_VIEW}'; } else if (rev_text.data == '{LA_COLLAPSE_VIEW}'){rev_text.data = '{LA_EXPAND_VIEW}'};">{L_EXPAND_VIEW}</a></span>
 	{L_MESSAGE_HISTORY}{L_COLON}
 </h3>
 
 <!-- EVENT ucp_pm_history_review_before -->
-<div id="topicreview">
+<div id="topicreview" class="topicreview">
 	<script type="text/javascript">
 	// <![CDATA[
 		bbcodeEnabled = {S_BBCODE_ALLOWED};
diff --git a/phpBB/styles/prosilver/template/ucp_pm_viewmessage_print.html b/phpBB/styles/prosilver/template/ucp_pm_viewmessage_print.html
index 55d81b4e69..70beec8256 100644
--- a/phpBB/styles/prosilver/template/ucp_pm_viewmessage_print.html
+++ b/phpBB/styles/prosilver/template/ucp_pm_viewmessage_print.html
@@ -10,8 +10,8 @@
 <!-- EVENT ucp_pm_viewmessage_print_head_append -->
 </head>
 <body id="phpbb">
-<div id="wrap">
-	<a id="top" class="anchor" accesskey="t"></a>
+<div id="wrap" class="wrap">
+	<a id="top" class="top-anchor" accesskey="t"></a>
 
 	<div id="page-header">
 		<h1>{SITENAME}</h1>
@@ -20,7 +20,7 @@
 		<h2>{L_PRIVATE_MESSAGING}</h2>
 	</div>
 
-	<div id="page-body">
+	<div id="page-body" class="page-body">
 		<div class="page-number">{PAGE_NUMBER}</div>
 			<div class="post">
 				<h3>{SUBJECT}</h3>
@@ -38,7 +38,7 @@
 			<hr />
 	</div>
 
-	<div id="page-footer">
+	<div id="page-footer" class="page-footer">
 		<div class="page-number">{S_TIMEZONE}<br />{PAGE_NUMBER}</div>
 		<div class="copyright">Powered by phpBB&reg; Forum Software &copy; phpBB Limited<br />https://www.phpbb.com/</div>
 	</div>
diff --git a/phpBB/styles/prosilver/template/viewtopic_print.html b/phpBB/styles/prosilver/template/viewtopic_print.html
index f65f1ab542..796111dd3c 100644
--- a/phpBB/styles/prosilver/template/viewtopic_print.html
+++ b/phpBB/styles/prosilver/template/viewtopic_print.html
@@ -10,8 +10,8 @@
 <!-- EVENT viewtopic_print_head_append -->
 </head>
 <body id="phpbb">
-<div id="wrap">
-	<a id="top" class="anchor" accesskey="t"></a>
+<div id="wrap" class="wrap">
+	<a id="top" class="top-anchor" accesskey="t"></a>
 
 	<div id="page-header">
 		<h1>{SITENAME}</h1>
@@ -21,7 +21,7 @@
 		<p><a href="{U_TOPIC}">{U_TOPIC}</a></p>
 	</div>
 
-	<div id="page-body">
+	<div id="page-body" class="page-body">
 		<div class="page-number">{PAGE_NUMBER}</div>
 		<!-- BEGIN postrow -->
 			<div class="post">
@@ -34,7 +34,7 @@
 		<!-- END postrow -->
 	</div>
 
-	<div id="page-footer">
+	<div id="page-footer" class="page-footer">
 		<div class="page-number">{S_TIMEZONE}<br />{PAGE_NUMBER}</div>
 		<div class="copyright">Powered by phpBB&reg; Forum Software &copy; phpBB Limited<br />https://www.phpbb.com/</div>
 	</div>
diff --git a/phpBB/styles/prosilver/theme/bidi.css b/phpBB/styles/prosilver/theme/bidi.css
index 47d4823fdb..c9063c9411 100644
--- a/phpBB/styles/prosilver/theme/bidi.css
+++ b/phpBB/styles/prosilver/theme/bidi.css
@@ -27,11 +27,11 @@
 
 /* Site Description
 --------------------------------------------- */
-.rtl #site-description {
+.rtl .site-description {
 	float: right;
 }
 
-.rtl #site-description h1 {
+.rtl .site-description h1 {
 	margin-left: 0;
 }
 
@@ -268,16 +268,7 @@
 
 /* Miscellaneous styles
 ---------------------------------------- */
-.rtl #forum-permissions {
-	float: left;
-	padding-right: 5px;
-	padding-left: 0;
-	margin-right: 5px;
-	margin-left: 0;
-	text-align: left;
-}
-
-.rtl #quick-links {
+.rtl .quick-links {
 	margin-left: 7px;
 	margin-right: 0;
 }
@@ -471,7 +462,7 @@ li.breadcrumbs span:first-child > a {
 
 /* Topic review panel
 ----------------------------------------*/
-.rtl #topicreview {
+.rtl .topicreview {
 	padding-right: 0;
 	padding-left: 5px;
 }
@@ -687,20 +678,20 @@ li.breadcrumbs span:first-child > a {
 
 /* Main CP box
 ----------------------------------------*/
-.rtl #cp-menu {
+.rtl .cp-menu {
 	float: right;
 }
 
-.rtl #cp-main {
+.rtl .cp-main {
 	float: right;
 }
 
-.rtl #cp-main .panel ol {
+.rtl .cp-main .panel ol {
 	margin-right: 2em;
 	margin-left: 0;
 }
 
-.rtl #cp-main .buttons {
+.rtl .cp-main .buttons {
 	margin-right: 0;
 	margin-left: 0;
 }
@@ -711,52 +702,52 @@ li.breadcrumbs span:first-child > a {
 
 /* CP tabbed menu
 ----------------------------------------*/
-.rtl #tabs {
+.rtl .tabs {
 	margin-left: 0;
 	margin-right: 7px;
 }
 
-.rtl #tabs .tab {
+.rtl .tabs .tab {
 	float: right;
 }
 
-.rtl #tabs .tab > a {
+.rtl .tabs .tab > a {
 	margin-left: 1px;
 	margin-right: 0;
 }
 
 /* Mini tabbed menu used in MCP
 ----------------------------------------*/
-.rtl #minitabs {
+.rtl .minitabs {
 	float: left;
 	margin-right: 0;
 	margin-left: 7px;
 }
 
-.rtl #minitabs .tab {
+.rtl .minitabs .tab {
 	float: left;
 }
 
-.rtl #minitabs .tab > a {
+.rtl .minitabs .tab > a {
 	margin-right: 2px;
 	margin-left: 0;
 }
 
 /* Responsive tabs
 ----------------------------------------*/
-.rtl #tabs .dropdown {
+.rtl .tabs .dropdown {
 	margin-left: -2px;
 }
 
-.rtl #tabs .dropdown li {
+.rtl .tabs .dropdown li {
 	text-align: left;
 }
 
-.rtl #minitabs .dropdown {
+.rtl .minitabs .dropdown {
 	margin-left: -4px;
 }
 
-.rtl #minitabs .dropdown li {
+.rtl .minitabs .dropdown li {
 	text-align: right;
 }
 
@@ -764,7 +755,7 @@ li.breadcrumbs span:first-child > a {
 ----------------------------------------*/
 @media only screen and (max-width: 900px), only screen and (max-device-width: 900px)
 {
-	.rtl #cp-menu, .rtl #navigation, .rtl #cp-main {
+	.rtl .cp-menu, .rtl .navigation, .rtl .cp-main {
 		float: none;
 	}
 }
@@ -774,7 +765,7 @@ li.breadcrumbs span:first-child > a {
 
 /* Preferences pane layout
 ----------------------------------------*/
-.rtl #cp-main h2 {
+.rtl .cp-main h2 {
 	margin-left: 0;
 	margin-right: 10px;
 }
@@ -815,7 +806,7 @@ li.breadcrumbs span:first-child > a {
 }
 
 /* Avatar gallery */
-.rtl #gallery label {
+.rtl .gallery label {
 	float: right;
 }
 
@@ -823,7 +814,7 @@ li.breadcrumbs span:first-child > a {
 ----------------------------------------*/
 @media only screen and (max-width: 900px), only screen and (max-device-width: 900px)
 {
-	.rtl #cp-menu, .rtl #navigation, .rtl #cp-main {
+	.rtl .cp-menu, .rtl .navigation, .rtl .cp-main {
 		float: none;
 	}
 }
@@ -935,7 +926,7 @@ li.breadcrumbs span:first-child > a {
 ----------------------------------------*/
 
 /* Emoticons panel */
-.rtl #smiley-box {
+.rtl .smiley-box {
 	float: left;
 }
 
@@ -984,7 +975,7 @@ li.breadcrumbs span:first-child > a {
 ---------------------------------------- */
 
 /** Reference: Bug #27155 */
-.rtl #wrap, .rtl .headerbar, .rtl #site-description, .rtl .navbar {
+.rtl .wrap, .rtl .headerbar, .rtl .site-description, .rtl .navbar {
 	position: relative;
 }
 
diff --git a/phpBB/styles/prosilver/theme/buttons.css b/phpBB/styles/prosilver/theme/buttons.css
index c62ee832f2..144852647d 100644
--- a/phpBB/styles/prosilver/theme/buttons.css
+++ b/phpBB/styles/prosilver/theme/buttons.css
@@ -61,7 +61,7 @@
 	margin-right: 5px;
 }
 
-#jumpbox .dropdown-select {
+.jumpbox .dropdown-select {
 	margin: 0;
 }
 
diff --git a/phpBB/styles/prosilver/theme/colours.css b/phpBB/styles/prosilver/theme/colours.css
index a4c1925cc7..7e7827154f 100644
--- a/phpBB/styles/prosilver/theme/colours.css
+++ b/phpBB/styles/prosilver/theme/colours.css
@@ -42,7 +42,7 @@ hr {
 
 /* Round cornered boxes and backgrounds
 ---------------------------------------- */
-#wrap {
+.wrap {
 	background-color: #FFF;
 	border-color: #E6E9ED;
 }
@@ -771,7 +771,7 @@ Colours and backgrounds for cp.css
 /* Main CP box
 ----------------------------------------*/
 
-.panel-container h3, .panel-container hr, #cp-menu hr {
+.panel-container h3, .panel-container hr, .cp-menu hr {
 	border-color: #A4B3BF;
 }
 
@@ -793,25 +793,25 @@ ul.cplist {
 	border-bottom-color: #333333;
 }
 
-#cp-main .pm-message {
+.cp-main .pm-message {
 	border-color: #DBDEE2;
 	background-color: #FFFFFF;
 }
 
 /* CP tabbed menu
 ----------------------------------------*/
-#tabs .tab > a {
+.tabs .tab > a {
 	background: #BACCD9;
 	color: #536482;
 }
 
-#tabs .tab > a:hover {
+.tabs .tab > a:hover {
 	background: #DDEDFB;
 	color: #D31141;
 }
 
-#tabs .activetab > a,
-#tabs .activetab > a:hover {
+.tabs .activetab > a,
+.tabs .activetab > a:hover {
 	background-color: #CADCEB; /* Old browsers */ /* FF3.6+ */
 	background-image: -webkit-linear-gradient(top, #E2F2FF 0%, #CADCEB 100%);
 	background-image: linear-gradient(to bottom, #E2F2FF 0%,#CADCEB 100%); /* W3C */
@@ -821,18 +821,18 @@ ul.cplist {
 	color: #333333;
 }
 
-#tabs .activetab > a:hover {
+.tabs .activetab > a:hover {
 	color: #000000;
 }
 
 /* Mini tabbed menu used in MCP
 ----------------------------------------*/
-#minitabs .tab > a {
+.minitabs .tab > a {
 	background-color: #E1EBF2;
 }
 
-#minitabs .activetab > a,
-#minitabs .activetab > a:hover {
+.minitabs .activetab > a,
+.minitabs .activetab > a:hover {
 	background-color: #F9F9F9;
 	color: #333333;
 }
@@ -851,7 +851,7 @@ ul.cplist {
 ----------------------------------------*/
 
 /* Link styles for the sub-section links */
-#navigation a {
+.navigation a {
 	color: #333;
 	background: #CADCEB; /* Old browsers */ /* FF3.6+ */
 	background: -webkit-linear-gradient(left, #B4C4D1 50%, #CADCEB 100%);
@@ -859,26 +859,26 @@ ul.cplist {
 	filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#B4C4D1', endColorstr='#CADCEB',GradientType=1 ); /* IE6-9 */
 }
 
-.rtl #navigation a {
+.rtl .navigation a {
 	background: #B4C4D1; /* Old browsers */ /* FF3.6+ */
 	background: -webkit-linear-gradient(left, #CADCEB 50%, #B4C4D1 100%);
 	background: linear-gradient(to right, #CADCEB 50%,#B4C4D1 100%); /* W3C */
 	filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#CADCEB', endColorstr='#B4C4D1',GradientType=1 ); /* IE6-9 */
 }
 
-#navigation a:hover {
+.navigation a:hover {
 	background: #AABAC6;
 	color: #BC2A4D;
 	filter: progid:DXImageTransform.Microsoft.gradient(enabled = false);
 }
 
-#navigation #active-subsection a {
+.navigation .active-subsection a {
 	background: #F9F9F9;
 	color: #D31141;
 	filter: progid:DXImageTransform.Microsoft.gradient(enabled = false);
 }
 
-#navigation #active-subsection a:hover {
+.navigation .active-subsection a:hover {
 	color: #D31141;
 }
 
@@ -899,7 +899,7 @@ ul.cplist {
 	background-color: #F9F9F9;
 }
 
-#cp-main .pm {
+.cp-main .pm {
 	background-color: #FFFFFF;
 }
 
@@ -942,12 +942,12 @@ dl.mini dt {
 }
 
 /* Avatar gallery */
-#gallery label {
+.gallery label {
 	background: #FFFFFF;
 	border-color: #CCC;
 }
 
-#gallery label:hover {
+.gallery label:hover {
 	background-color: #EEE;
 }
 
@@ -999,15 +999,15 @@ fieldset.quick-login input.inputbox {
 /* Posting page styles
 ----------------------------------------*/
 
-#message-box textarea {
+.message-box textarea {
 	color: #333333;
 }
 
-#message-box textarea.drag-n-drop {
+.message-box textarea.drag-n-drop {
 	outline-color: rgba(102, 102, 102, 0.5);
 }
 
-#message-box textarea.drag-n-drop-highlight {
+.message-box textarea.drag-n-drop-highlight {
 	outline-color: rgba(17, 163, 234, 0.5);
 }
 
@@ -1107,11 +1107,11 @@ input.disabled {
 .phpbb_alert .alert_close {
 	background-image: url("./images/alert_close.png");
 }
-#darken {
+.darken {
 	background-color: #000000;
 }
 
-#loading_indicator {
+.loading_indicator {
 	background-color: #000000;
 	background-image: url("./images/loading.gif");
 }
diff --git a/phpBB/styles/prosilver/theme/common.css b/phpBB/styles/prosilver/theme/common.css
index 35e0ab4935..827dcb1703 100644
--- a/phpBB/styles/prosilver/theme/common.css
+++ b/phpBB/styles/prosilver/theme/common.css
@@ -126,7 +126,7 @@ ol ol ul, ol ul ul, ul ol ul, ul ul ul {
 
 /* Main blocks
 ---------------------------------------- */
-#wrap {
+.wrap {
 	border: 1px solid transparent;
 	border-radius: 8px;
 	margin: 0 auto;
@@ -136,21 +136,21 @@ ol ol ul, ol ul ul, ul ol ul, ul ul ul {
 }
 
 @media only screen and (max-width: 1220px), only screen and (max-device-width: 1220px) {
-	#wrap {
+	.wrap {
 		margin: 0 12px;
 	}
 }
 
-#page-body {
+.page-body {
 	margin: 4px 0;
 	clear: both;
 }
 
-#page-footer {
+.page-footer {
 	clear: both;
 }
 
-#page-footer h3 {
+.page-footer h3 {
 	margin-top: 20px;
 }
 
@@ -165,12 +165,12 @@ ol ol ul, ol ul ul, ul ol ul, ul ul ul {
 }
 
 /* Site description and logo */
-#site-description {
+.site-description {
 	float: left;
 	width: 65%;
 }
 
-#site-description h1 {
+.site-description h1 {
 	margin-right: 0;
 }
 
@@ -231,7 +231,7 @@ ul.linklist {
 	margin: 0;
 }
 
-#cp-main .panel {
+.cp-main .panel {
 	padding: 5px 10px;
 }
 
@@ -275,7 +275,7 @@ ul.linklist li.responsive-menu {
 	margin: 0 5px;
 }
 
-ul.linklist li.responsive-menu a.responsive-menu-link {
+ul.linklist .responsive-menu-link {
 	display: inline-block;
 	margin: 0 5px;
 	font-size: 1.455em;
@@ -285,7 +285,7 @@ ul.linklist li.responsive-menu a.responsive-menu-link {
 	text-decoration: none;
 }
 
-ul.linklist li.responsive-menu a.responsive-menu-link:before {
+ul.linklist .responsive-menu-link:before {
 	content: '';
 	position: absolute;
 	left: 0;
@@ -491,6 +491,9 @@ ul.linklist.bulletin > li.no-bulletin:before {
 	padding: 5px;
 }
 
+.jumpbox {
+	margin: 5px 0;
+}
 
 .jumpbox .dropdown li {
 	border-top: 1px solid transparent;
@@ -619,10 +622,6 @@ table.table1 {
 	width: 100%;
 }
 
-#ucp-main table.table1 {
-	padding: 2px;
-}
-
 table.table1 thead th {
 	font-weight: normal;
 	text-transform: uppercase;
@@ -691,7 +690,7 @@ table.info tbody th {
 	margin: 0 -1px;
 }
 
-#color_palette_placeholder table {
+.color_palette_placeholder table {
 	border-collapse: separate;
 	border-spacing: 1px;
 }
@@ -941,13 +940,13 @@ fieldset.fields1 dl.pmlist dd.recipients {
 	font-size: 1.1em;
 }
 
-#darkenwrapper {
+.darkenwrapper {
 	display: none;
 	position: relative;
 	z-index: 44;
 }
 
-#darken {
+.darken {
 	position: fixed;
 	left: 0;
 	top: 0;
@@ -957,7 +956,7 @@ fieldset.fields1 dl.pmlist dd.recipients {
 	z-index: 45;
 }
 
-#loading_indicator {
+.loading_indicator {
 	background: center center no-repeat;
 	border-radius: 5px;
 	display: none;
@@ -974,15 +973,6 @@ fieldset.fields1 dl.pmlist dd.recipients {
 
 /* Miscellaneous styles
 ---------------------------------------- */
-#forum-permissions {
-	float: right;
-	width: auto;
-	padding-left: 5px;
-	margin-left: 5px;
-	margin-top: 10px;
-	text-align: right;
-}
-
 .copyright {
 	padding: 5px;
 	text-align: center;
@@ -1040,15 +1030,12 @@ form > p.post-notice strong {
 	line-height: 20px;
 }
 
-#jumpbox {
-	margin: 5px 0;
-}
-
 .stat-block {
 	clear: both;
 }
 
-#top {
+.top-anchor {
+	display: block;
 	position: absolute;
 	top: -20px;
 }
@@ -1067,8 +1054,8 @@ ul.linklist:after,
 .action-bar:after,
 .notification_text:after,
 .tabs-container:after,
-#tabs > ul:after,
-#minitabs > ul:after,
+.tabs > ul:after,
+.minitabs > ul:after,
 .postprofile .avatar-container:after {
 	clear: both;
 	content: '';
@@ -1243,11 +1230,11 @@ ul.linklist:after,
 /* Navbar specific list items
 ----------------------------------------*/
 
-#quick-links {
+.linklist .quick-links {
 	margin: 0 7px 0 0;
 }
 
-#quick-links a.responsive-menu-link {
+.linklist .quick-links .responsive-menu-link {
 	display: block;
 	font-size: inherit;
 	line-height: inherit;
@@ -1255,12 +1242,12 @@ ul.linklist:after,
 	width: auto;
 }
 
-#quick-links a.responsive-menu-link:before {
+.linklist .quick-links .responsive-menu-link:before {
 	font-size: 1.455em;
 	line-height: 16.5px;
 }
 
-.compact #quick-links a.responsive-menu-link {
+.compact .quick-links .responsive-menu-link {
 	width: 0;
 	overflow: hidden;
 	white-space: nowrap;
diff --git a/phpBB/styles/prosilver/theme/content.css b/phpBB/styles/prosilver/theme/content.css
index 758cc8a771..1c2bc1bb3c 100644
--- a/phpBB/styles/prosilver/theme/content.css
+++ b/phpBB/styles/prosilver/theme/content.css
@@ -282,28 +282,28 @@ dd.option {
 
 /* Topic review panel
 ----------------------------------------*/
-#review {
+.panel .review {
 	margin-top: 2em;
 }
 
-#topicreview {
+.topicreview {
 	padding-right: 5px;
 	overflow: auto;
 	height: 300px;
 }
 
-#topicreview .postbody {
+.topicreview .postbody {
 	width: auto;
 	float: none;
 	margin: 0;
 	height: auto;
 }
 
-#topicreview .post {
+.topicreview .post {
 	height: auto;
 }
 
-#topicreview h2 {
+.topicreview h2 {
 	border-bottom-width: 0;
 }
 
@@ -313,7 +313,7 @@ dd.option {
 
 /* MCP Post details
 ----------------------------------------*/
-#post_details {
+.post_details {
 	/* This will only work in IE7+, plus the others */
 	overflow: auto;
 	max-height: 300px;
@@ -829,7 +829,7 @@ table.fixed-width-table {
 
 /* Show scrollbars for items with overflow on iOS devices
 ----------------------------------------*/
-.postbody .content::-webkit-scrollbar, #topicreview::-webkit-scrollbar, #post_details::-webkit-scrollbar, .codebox code::-webkit-scrollbar, .attachbox dd::-webkit-scrollbar, .attach-image::-webkit-scrollbar, .dropdown-extended ul::-webkit-scrollbar {
+.postbody .content::-webkit-scrollbar, .topicreview::-webkit-scrollbar, .post_details::-webkit-scrollbar, .codebox code::-webkit-scrollbar, .attachbox dd::-webkit-scrollbar, .attach-image::-webkit-scrollbar, .dropdown-extended ul::-webkit-scrollbar {
 	width: 8px;
 	height: 8px;
 	-webkit-appearance: none;
@@ -837,7 +837,7 @@ table.fixed-width-table {
 	border-radius: 3px;
 }
 
-.postbody .content::-webkit-scrollbar-thumb, #topicreview::-webkit-scrollbar-thumb, #post_details::-webkit-scrollbar-thumb, .codebox code::-webkit-scrollbar-thumb, .attachbox dd::-webkit-scrollbar-thumb, .attach-image::-webkit-scrollbar-thumb, .dropdown-extended ul::-webkit-scrollbar-thumb {
+.postbody .content::-webkit-scrollbar-thumb, .topicreview::-webkit-scrollbar-thumb, .post_details::-webkit-scrollbar-thumb, .codebox code::-webkit-scrollbar-thumb, .attachbox dd::-webkit-scrollbar-thumb, .attach-image::-webkit-scrollbar-thumb, .dropdown-extended ul::-webkit-scrollbar-thumb {
 	background: rgba(0, 0, 0, .3);
 	border-radius: 3px;
 }
diff --git a/phpBB/styles/prosilver/theme/cp.css b/phpBB/styles/prosilver/theme/cp.css
index 8a223f653f..d54c948343 100644
--- a/phpBB/styles/prosilver/theme/cp.css
+++ b/phpBB/styles/prosilver/theme/cp.css
@@ -4,19 +4,19 @@
 
 /* Main CP box
 ----------------------------------------*/
-#cp-menu {
+.cp-menu {
 	float:left;
 	width: 19%;
 	margin-top: 1em;
 	margin-bottom: 5px;
 }
 
-#cp-main {
+.cp-main {
 	float: left;
 	width: 81%;
 }
 
-#cp-main .content {
+.cp-main .content {
 	padding: 0;
 }
 
@@ -59,7 +59,7 @@ ul.cplist {
 	border-bottom: none;
 }
 
-#cp-main .pm-message {
+.cp-main .pm-message {
 	border: 1px solid transparent;
 	margin: 10px 0;
 	width: auto;
@@ -70,7 +70,7 @@ ul.cplist {
 	padding-bottom: 5px;
 }
 
-#cp-main .postbody h3, #cp-main .box2 h3 {
+.cp-main .postbody h3, .cp-main .box2 h3 {
 	margin-top: 0;
 }
 
@@ -78,11 +78,11 @@ ul.cplist {
 	font-size: 1.1em;
 }
 
-#cp-main .buttons {
+.cp-main .buttons {
 	margin-left: 0;
 }
 
-#cp-main ul.linklist {
+.cp-main ul.linklist {
 	margin: 0;
 }
 
@@ -98,18 +98,18 @@ ul.cplist {
 
 /* CP tabs shared
 ----------------------------------------*/
-#tabs, #minitabs {
+.tabs, .minitabs {
 	line-height: normal;
 }
 
-#tabs > ul, #minitabs > ul {
+.tabs > ul, .minitabs > ul {
 	list-style: none;
 	margin: 0;
 	padding: 0;
 	position: relative;
 }
 
-#tabs .tab, #minitabs .tab {
+.tabs .tab, .minitabs .tab {
 	display: block;
 	float: left;
 	font-size: 1em;
@@ -117,7 +117,7 @@ ul.cplist {
 	line-height: 1.4em;
 }
 
-#tabs .tab > a, #minitabs .tab > a {
+.tabs .tab > a, .minitabs .tab > a {
 	display: block;
 	padding: 5px 9px;
 	position: relative;
@@ -128,39 +128,39 @@ ul.cplist {
 
 /* CP tabbed menu
 ----------------------------------------*/
-#tabs {
+.tabs {
 	margin: 20px 0 0 7px;
 }
 
-#tabs .tab > a {
+.tabs .tab > a {
 	border: 1px solid transparent;
 	border-radius: 4px 4px 0 0;
 	margin: 1px 1px 0 0;
 }
 
-#tabs .activetab > a {
+.tabs .activetab > a {
 	margin-top: 0;
 	padding-bottom: 7px;
 }
 
 /* Mini tabbed menu used in MCP
 ----------------------------------------*/
-#minitabs {
+.minitabs {
 	float: right;
 	margin: 15px 7px 0 0;
 	max-width: 50%;
 }
 
-#minitabs .tab {
+.minitabs .tab {
 	float: right;
 }
 
-#minitabs .tab > a {
+.minitabs .tab > a {
 	border-radius: 5px 5px 0 0;
 	margin-left: 2px;
 }
 
-#minitabs .tab > a:hover {
+.minitabs .tab > a:hover {
 	text-decoration: none;
 }
 
@@ -190,44 +190,44 @@ ul.cplist {
 	border-top: 0.375em double transparent;
 }
 
-#tabs .dropdown, #minitabs .dropdown {
+.tabs .dropdown, .minitabs .dropdown {
 	top: 20px;
 	margin-right: -2px;
 	font-size: 1.1em;
 	font-weight: normal;
 }
 
-#minitabs .dropdown {
+.minitabs .dropdown {
 	margin-right: -4px;
 }
 
-#tabs .dropdown-up .dropdown, #minitabs .dropdown-up .dropdown {
+.tabs .dropdown-up .dropdown, .minitabs .dropdown-up .dropdown {
 	bottom: 20px;
 	top: auto;
 }
 
-#tabs .dropdown li {
+.tabs .dropdown li {
 	text-align: right;
 }
 
-#minitabs .dropdown li {
+.minitabs .dropdown li {
 	text-align: left;
 }
 
 /* UCP navigation menu
 ----------------------------------------*/
 /* Container for sub-navigation list */
-#navigation {
+.navigation {
 	width: 100%;
 	padding-top: 36px;
 }
 
-#navigation ul {
+.navigation ul {
 	list-style: none;
 }
 
 /* Default list state */
-#navigation li {
+.navigation li {
 	display: inline;
 	font-weight: bold;
 	margin: 1px 0;
@@ -235,20 +235,20 @@ ul.cplist {
 }
 
 /* Link styles for the sub-section links */
-#navigation a {
+.navigation a {
 	display: block;
 	padding: 5px;
 	margin: 1px 0;
 	text-decoration: none;
 }
 
-#navigation a:hover {
+.navigation a:hover {
 	text-decoration: none;
 }
 
 /* Preferences pane layout
 ----------------------------------------*/
-#cp-main h2 {
+.cp-main h2 {
 	border-bottom: none;
 	padding: 0;
 	margin-left: 10px;
@@ -281,10 +281,6 @@ dl.mini dd {
 
 /* PM Styles
 ----------------------------------------*/
-#pm-menu {
-	line-height: 2.5em;
-}
-
 /* Defined rules list for PM options */
 ol.def-rules {
 	padding-left: 0;
@@ -327,7 +323,7 @@ ol.def-rules li {
 }
 
 /* Avatar gallery */
-#gallery label {
+.gallery label {
 	position: relative;
 	float: left;
 	margin: 10px;
@@ -341,35 +337,35 @@ ol.def-rules li {
 ----------------------------------------*/
 @media only screen and (max-width: 900px), only screen and (max-device-width: 900px)
 {
-	.nojs #tabs a span, .nojs #minitabs a span {
+	.nojs .tabs a span, .nojs .minitabs a span {
 		max-width: 40px;
 		overflow: hidden;
 		text-overflow: ellipsis;
 		letter-spacing: -.5px;
 	}
 
-	#cp-menu, #navigation, #cp-main {
+	.cp-menu, .navigation, .cp-main {
 		float: none;
 		width: auto;
 		margin: 0;
 	}
 
-	#navigation {
+	.navigation {
 		padding: 0;
 		margin: 0 auto;
 		max-width: 320px;
 	}
 
-	#navigation a {
+	.navigation a {
 		background-image: none;
 	}
 
-	#navigation li:first-child a {
+	.navigation li:first-child a {
 		border-top-left-radius: 5px;
 		border-top-right-radius: 5px;
 	}
 
-	#navigation li:last-child a {
+	.navigation li:last-child a {
 		border-bottom-left-radius: 5px;
 		border-bottom-right-radius: 5px;
 	}
diff --git a/phpBB/styles/prosilver/theme/forms.css b/phpBB/styles/prosilver/theme/forms.css
index 27b33f74aa..2ece0cda69 100644
--- a/phpBB/styles/prosilver/theme/forms.css
+++ b/phpBB/styles/prosilver/theme/forms.css
@@ -96,7 +96,7 @@ fieldset.fields1 div {
 }
 
 /* Set it back to 0px for the reCaptcha divs: PHPBB3-9587 */
-fieldset.fields1 #recaptcha_widget_div div, fieldset.fields1 .live-search div {
+fieldset.fields1 .live-search div {
 	margin-bottom: 0;
 }
 
@@ -138,7 +138,7 @@ dd textarea {
 }
 
 /* Hover effects */
-#timezone {
+.timezone {
 	width: 95%;
 }
 
@@ -222,20 +222,20 @@ fieldset.submit-buttons input {
 ----------------------------------------*/
 
 /* Buttons used in the editor */
-#format-buttons {
+.format-buttons {
 	margin: 15px 0 2px 0;
 }
 
-#format-buttons input, #format-buttons select {
+.format-buttons input, .format-buttons select {
 	vertical-align: middle;
 }
 
 /* Main message box */
-#message-box {
+.message-box {
 	width: 80%;
 }
 
-#message-box textarea {
+.message-box textarea {
 	font-family: "Trebuchet MS", Verdana, Helvetica, Arial, sans-serif;
 	width: 450px;
 	height: 270px;
@@ -253,12 +253,12 @@ fieldset.submit-buttons input {
 }
 
 /* Emoticons panel */
-#smiley-box {
+.smiley-box {
 	width: 18%;
 	float: right;
 }
 
-#smiley-box img {
+.smiley-box img {
 	margin: 3px;
 }
 
diff --git a/phpBB/styles/prosilver/theme/plupload.css b/phpBB/styles/prosilver/theme/plupload.css
index 7d4092c3fe..bbbf7ebe53 100644
--- a/phpBB/styles/prosilver/theme/plupload.css
+++ b/phpBB/styles/prosilver/theme/plupload.css
@@ -1,9 +1,9 @@
-#attach-panel-multi {
+.attach-panel-multi {
 	display: none;
 	margin-bottom: 1em;
 }
 
-#file-list td {
+.file-list td {
 	vertical-align: middle;
 }
 
@@ -32,11 +32,11 @@
 	float: right;
 }
 
-#attach-row-tpl, .nojs .file-inline-bbcode {
+.nojs .file-inline-bbcode {
 	display: none;
 }
 
-#file-total-progress {
+.file-total-progress {
 	height: 2px;
 	display: block;
 	position: relative;
@@ -50,7 +50,7 @@
 	width: 50px;
 }
 
-.file-progress-bar, #file-total-progress-bar {
+.file-progress-bar, .file-total-progress-bar {
 	background-color: green;
 	display: block;
 	height: 100%;
diff --git a/phpBB/styles/prosilver/theme/print.css b/phpBB/styles/prosilver/theme/print.css
index 34129c92e8..a3295ac367 100644
--- a/phpBB/styles/prosilver/theme/print.css
+++ b/phpBB/styles/prosilver/theme/print.css
@@ -19,14 +19,14 @@ a:link		{ color: #000000; text-decoration: none; }
 a:visited	{ color: #000000; text-decoration: none; }
 a:active	{ color: #000000; text-decoration: none; }
 
-img, .noprint, #sub-header, #sub-footer, .navbar, .box1, .divider, .signature { display: none; }
+img, .noprint, .navbar, .box1, .divider, .signature { display: none; }
 /* Display smilies (Bug #47265) */
 .content img {
 	display: inline;
 }
 
 /* Container for the main body */
-#wrap {
+.wrap {
 	margin: 0 2em;
 }
 
diff --git a/phpBB/styles/prosilver/theme/responsive.css b/phpBB/styles/prosilver/theme/responsive.css
index 8653042a69..a32d907b46 100644
--- a/phpBB/styles/prosilver/theme/responsive.css
+++ b/phpBB/styles/prosilver/theme/responsive.css
@@ -16,7 +16,7 @@ body {
 	padding: 0;
 }
 
-#wrap {
+.wrap {
 	border: none;
 	border-radius: 0;
 	margin: 0;
@@ -32,13 +32,13 @@ body {
 	margin-right: -5px;
 }
 
-#cp-main .forabg, #cp-main .forumdb, #cp-main .post, #cp-main .panel {
+.cp-main .forabg, .cp-main .forumdb, .cp-main .post, .cp-main .panel {
 	border-radius: 7px;
 }
 
 /* Logo block
 ----------------------------------------*/
-#site-description {
+.site-description {
 	float: none;
 	width: auto;
 	text-align: center;
@@ -51,7 +51,7 @@ body {
 	padding: 10px;
 }
 
-#site-description h1, #site-description p {
+.site-description h1, .site-description p {
 	text-align: inherit;
 	float: none;
 	margin: 5px;
@@ -60,7 +60,7 @@ body {
 	text-overflow: ellipsis;
 }
 
-#site-description p, .search-header {
+.site-description p, .search-header {
 	display: none;
 }
 
@@ -254,7 +254,7 @@ table.responsive span.rank-img {
 	padding-right: 5px;
 }
 
-table.responsive#memberlist td:first-child input[type="checkbox"] {
+table.responsive.memberlist td:first-child input[type="checkbox"] {
 	float: right;
 }
 
@@ -269,7 +269,7 @@ fieldset dd, fieldset.fields1 dd, fieldset.fields2 dd {
 	margin-left: 20px;
 }
 
-textarea, dd textarea, #message-box textarea {
+textarea, dd textarea, .message-box textarea {
 	width: 100%;
 	-moz-box-sizing: border-box;
 	box-sizing: border-box;
@@ -289,12 +289,12 @@ dl.pmlist dd:first-of-type {
 	padding-left: 20px;
 }
 
-#smiley-box, #message-box {
+.smiley-box, .message-box {
 	float: none;
 	width: auto;
 }
 
-#smiley-box {
+.smiley-box {
 	margin-top: 5px;
 }
 
@@ -359,13 +359,6 @@ fieldset.quick-login label[for="autologin"] {
 		width: 100%;
 	}
 
-	#recaptcha_challenge_image,
-	#recaptcha_response_field,
-	.recaptchatable #recaptcha_image {
-		width: 100% !important;
-		height: auto !important;
-	}
-
 	.recaptchatable tr td:last-child {
 		display: none;
 	}
@@ -518,7 +511,7 @@ dl.mini dd.pm-legend {
 	min-width: 200px;
 }
 
-#topicreview {
+.topicreview {
 	margin: 0 -5px;
 	padding: 0 5px;
 }
diff --git a/phpBB/styles/prosilver/theme/tweaks.css b/phpBB/styles/prosilver/theme/tweaks.css
index 4bd9d2099f..ba82551f85 100644
--- a/phpBB/styles/prosilver/theme/tweaks.css
+++ b/phpBB/styles/prosilver/theme/tweaks.css
@@ -36,6 +36,6 @@ dd label input { vertical-align: text-bottom\9; }
 	background-image: url("./images/bg_list.gif");
 }
 
-#tabs .tab > a {
+.tabs .tab > a {
 	border-radius: 0;
 }