diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 208e9d724e..6256534eb7 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -27,3 +27,7 @@ jobs:
         bundler-cache: true
     - name: Run rubocop
       run: bundle exec rubocop
+    - name: Run herb linter
+      # npx should be available by default so we don't need `setup-node` action
+      # Don't lint erb files outside of lib as the current directory also includes vendor/bundle
+      run: npx @herb-tools/linter "lib/**/*.rhtml"
diff --git a/.vscode/extensions.json b/.vscode/extensions.json
new file mode 100644
index 0000000000..d49e5d015d
--- /dev/null
+++ b/.vscode/extensions.json
@@ -0,0 +1,5 @@
+{
+    "recommendations": [
+        "marcoroth.herb-lsp"
+    ]
+}
diff --git a/lib/rdoc/generator/template/darkfish/_footer.rhtml b/lib/rdoc/generator/template/darkfish/_footer.rhtml
index 9791b42901..620cf01484 100644
--- a/lib/rdoc/generator/template/darkfish/_footer.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_footer.rhtml
@@ -1,5 +1,5 @@
 <footer id="validator-badges" role="contentinfo">
-  <p><a href="https://validator.w3.org/check/referer">Validate</a>
-  <p>Generated by <a href="https://ruby.github.io/rdoc/">RDoc</a> <%= RDoc::VERSION %>.
-  <p>Based on <a href="http://deveiate.org/projects/Darkfish-RDoc/">Darkfish</a> by <a href="http://deveiate.org">Michael Granger</a>.
+  <p><a href="https://validator.w3.org/check/referer">Validate</a></p>
+  <p>Generated by <a href="https://ruby.github.io/rdoc/">RDoc</a> <%= RDoc::VERSION %>.</p>
+  <p>Based on <a href="http://deveiate.org/projects/Darkfish-RDoc/">Darkfish</a> by <a href="http://deveiate.org">Michael Granger</a>.</p>
 </footer>
diff --git a/lib/rdoc/generator/template/darkfish/_head.rhtml b/lib/rdoc/generator/template/darkfish/_head.rhtml
index 7376fc390e..eeae0acb03 100644
--- a/lib/rdoc/generator/template/darkfish/_head.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_head.rhtml
@@ -1,34 +1,34 @@
 <meta charset="<%= @options.charset %>">
-<meta name="viewport" content="width=device-width, initial-scale=1" />
+<meta name="viewport" content="width=device-width, initial-scale=1">
 
 <title><%= h @title %></title>
 
-<%- if defined?(klass) -%>
+<%- if defined?(klass) %>
   <meta name="keywords" content="ruby,<%= h "#{klass.type},#{klass.full_name}" %>">
 
-  <%- if klass.comment.empty? -%>
+  <%- if klass.comment.empty? %>
     <meta name="description" content="Documentation for the <%= h "#{klass.full_name} #{klass.type}" %>">
-  <%- else -%>
+  <%- else %>
     <meta name="description" content="<%= h "#{klass.type} #{klass.full_name}: #{excerpt(klass.comment)}" %>">
-  <%- end -%>
-<%- elsif defined?(file) -%>
+  <%- end %>
+<%- elsif defined?(file) %>
   <meta name="keywords" content="ruby,documentation,<%= h file.page_name %>">
   <meta name="description" content="<%= h "#{file.page_name}: #{excerpt(file.comment)}" %>">
-<%- elsif @title -%>
+<%- elsif @title %>
   <meta name="keywords" content="ruby,documentation,<%= h @title %>">
 
   <%- if @options.main_page and
       main_page = @files.find { |f| f.full_name == @options.main_page } then %>
     <meta name="description" content="<%= h "#{@title}: #{excerpt(main_page.comment)}" %>">
-  <%- else -%>
+  <%- else %>
     <meta name="description" content="Documentation for <%= h @title %>">
-  <%- end -%>
-<%- end -%>
+  <%- end %>
+<%- end %>
 
-<%- if canonical_url = @options.canonical_root -%>
+<%- if canonical_url = @options.canonical_root %>
 <% canonical_url = current.canonical_url if defined?(current) %>
 <link rel="canonical" href="<%= canonical_url %>">
-<%- end -%>
+<%- end %>
 
 <script type="text/javascript">
   var rdoc_rel_prefix = "<%= h asset_rel_prefix %>/";
@@ -43,6 +43,6 @@
 
 <link href="<%= h asset_rel_prefix %>/css/fonts.css" rel="stylesheet">
 <link href="<%= h asset_rel_prefix %>/css/rdoc.css" rel="stylesheet">
-<%- @options.template_stylesheets.each do |stylesheet| -%>
+<%- @options.template_stylesheets.each do |stylesheet| %>
 <link href="<%= h asset_rel_prefix %>/<%= File.basename stylesheet %>" rel="stylesheet">
-<%- end -%>
+<%- end %>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_extends.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_extends.rhtml
index 067bd62edd..b83c1ef29c 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_extends.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_extends.rhtml
@@ -3,13 +3,13 @@
   <h3>Extended With Modules</h3>
 
   <ul class="link-list">
-    <%- klass.extends.each do |ext| -%>
-  <%- unless String === ext.module then -%>
-    <li><a class="extend" href="<%= klass.aref_to ext.module.path %>"><%= ext.module.full_name %></a>
-  <%- else -%>
-    <li><span class="extend"><%= ext.name %></span>
-  <%- end -%>
-  <%- end -%>
+  <%- klass.extends.each do |ext| %>
+  <%- unless String === ext.module then %>
+    <li><a class="extend" href="<%= klass.aref_to ext.module.path %>"><%= ext.module.full_name %></a></li>
+  <%- else %>
+    <li><span class="extend"><%= ext.name %></span></li>
+  <%- end %>
+  <%- end %>
   </ul>
 </div>
-<%- end -%>
+<%- end %>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_includes.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_includes.rhtml
index 04846f84fb..cc2255f861 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_includes.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_includes.rhtml
@@ -3,13 +3,13 @@
   <h3>Included Modules</h3>
 
   <ul class="link-list">
-  <%- klass.includes.each do |inc| -%>
-  <%- unless String === inc.module then -%>
-    <li><a class="include" href="<%= klass.aref_to inc.module.path %>"><%= inc.module.full_name %></a>
-  <%- else -%>
-    <li><span class="include"><%= inc.name %></span>
-  <%- end -%>
-  <%- end -%>
+  <%- klass.includes.each do |inc| %>
+  <%- unless String === inc.module then %>
+    <li><a class="include" href="<%= klass.aref_to inc.module.path %>"><%= inc.module.full_name %></a></li>
+  <%- else %>
+    <li><span class="include"><%= inc.name %></span></li>
+  <%- end %>
+  <%- end %>
   </ul>
 </div>
-<%- end -%>
+<%- end %>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_installed.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_installed.rhtml
index faed7e0a94..b20310556a 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_installed.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_installed.rhtml
@@ -2,14 +2,15 @@
   <h3>Documentation</h3>
 
   <ul>
-  <%- installed.each do |name, href, exists, type, _| -%>
-    <%- next if type == :extra -%>
+  <%- installed.each do |name, href, exists, type, _| %>
+    <%- next if type == :extra %>
     <li class="folder">
-    <%- if exists then -%>
+    <%- if exists then %>
       <a href="<%= href %>"><%= h name %></a>
-    <%- else -%>
+    <%- else %>
       <%= h name %>
-    <%- end -%>
-  <%- end -%>
+    <%- end %>
+    </li>
+  <%- end %>
   </ul>
 </div>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_methods.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_methods.rhtml
index d09216a0f6..67bf7c47aa 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_methods.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_methods.rhtml
@@ -2,9 +2,9 @@
   <div class="nav-section">
     <h3>Class Methods</h3>
     <ul class="link-list" role="directory">
-      <%- class_methods.each do |meth| -%>
-      <li <%- if meth.calls_super %>class="calls-super" <%- end %>><a href="#<%= meth.aref %>"><%= h meth.name -%></a></li>
-      <%- end -%>
+      <%- class_methods.each do |meth| %>
+      <li <%- if meth.calls_super %>class="calls-super" <%- end %>><a href="#<%= meth.aref %>"><%= h meth.name %></a></li>
+      <%- end %>
     </ul>
   </div>
 <% end %>
@@ -13,9 +13,9 @@
   <div class="nav-section">
     <h3>Instance Methods</h3>
     <ul class="link-list" role="directory">
-      <%- instance_methods.each do |meth| -%>
-      <li <%- if meth.calls_super %>class="calls-super" <%- end %>><a href="#<%= meth.aref %>"><%= h meth.name -%></a></li>
-      <%- end -%>
+      <%- instance_methods.each do |meth| %>
+      <li <%- if meth.calls_super %>class="calls-super" <%- end %>><a href="#<%= meth.aref %>"><%= h meth.name %></a></li>
+      <%- end %>
     </ul>
   </div>
 <% end %>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_pages.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_pages.rhtml
index 3f68f0c0dc..d6e0650abc 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_pages.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_pages.rhtml
@@ -1,32 +1,32 @@
 <%- simple_files = @files.select { |f| f.text? } %>
-<%- if defined?(current) -%>
-  <%- dir = current.full_name[%r{\A[^/]+(?=/)}] || current.page_name -%>
-<%- end -%>
-<%- unless simple_files.empty? then -%>
+<%- if defined?(current) %>
+  <%- dir = current.full_name[%r{\A[^/]+(?=/)}] || current.page_name %>
+<%- end %>
+<%- unless simple_files.empty? then %>
 <div id="fileindex-section" class="nav-section">
   <h3>Pages</h3>
 
   <ul class="link-list">
-  <%- simple_files.group_by do |f| -%>
-    <%- f.full_name[%r{\A[^/]+(?=/)}] || f.page_name -%>
-  <%- end.each do |n, files| -%>
-    <%- f = files.shift -%>
-    <%- if files.empty? -%>
-    <li><a href="<%= rel_prefix %>/<%= h f.path %>"><%= h f.page_name %></a>
-      <%- next -%>
-    <%- end -%>
-    <li><details<% if dir == n %> open<% end %>><summary><%
+  <%- simple_files.group_by do |f|
+    f.full_name[%r{\A[^/]+(?=/)}] || f.page_name
+  end.each do |n, files| %>
+    <%- f = files.shift %>
+    <%- if files.empty? %>
+    <li><a href="<%= rel_prefix %>/<%= h f.path %>"><%= h f.page_name %></a></li>
+      <%- next %>
+    <%- end %>
+    <li><details<%= ' open' if dir == n %>><summary><%
     if n == f.page_name
       %><a href="<%= rel_prefix %>/<%= h f.path %>"><%= h n %></a><%
     else
       %><%= h n %><% files.unshift(f)
     end %></summary>
     <ul class="link-list">
-    <%- files.each do |f| -%>
-      <li><a href="<%= rel_prefix %>/<%= h f.path %>"><%= h f.page_name %></a>
-    <%- end -%>
-    </ul></details>
-  <%- end -%>
+    <%- files.each do |f| %>
+      <li><a href="<%= rel_prefix %>/<%= h f.path %>"><%= h f.page_name %></a></li>
+    <%- end %>
+    </ul></details></li>
+  <%- end %>
   </ul>
 </div>
-<%- end -%>
+<%- end %>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_parent.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_parent.rhtml
index 6808b2bf87..497b4a669a 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_parent.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_parent.rhtml
@@ -1,6 +1,6 @@
-<%- if klass.type == 'class' && (ancestors = klass.super_classes).any? -%>
+<%- if klass.type == 'class' && (ancestors = klass.super_classes).any? %>
 <div id="parent-class-section" class="nav-section">
   <h3>Ancestors</h3>
   <%= generate_ancestor_list(ancestors, klass) %>
 </div>
-<%- end -%>
+<%- end %>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_sections.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_sections.rhtml
index 6dcd2ae81f..b275657c8e 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_sections.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_sections.rhtml
@@ -3,9 +3,9 @@
   <h3>Sections</h3>
 
   <ul class="link-list" role="directory">
-    <%- klass.sort_sections.each do |section| -%>
+    <%- klass.sort_sections.each do |section| %>
       <li><a href="#<%= section.aref %>"><%= h section.title %></a></li>
-    <%- end -%>
+    <%- end %>
   </ul>
 </div>
-<%- end -%>
+<%- end %>
diff --git a/lib/rdoc/generator/template/darkfish/_sidebar_table_of_contents.rhtml b/lib/rdoc/generator/template/darkfish/_sidebar_table_of_contents.rhtml
index b1e047b5f7..7561e4c05a 100644
--- a/lib/rdoc/generator/template/darkfish/_sidebar_table_of_contents.rhtml
+++ b/lib/rdoc/generator/template/darkfish/_sidebar_table_of_contents.rhtml
@@ -9,31 +9,31 @@
 <div class="nav-section">
   <h3>Table of Contents</h3>
 
-    <%- display_link = proc do |heading| -%>
+    <%- display_link = proc do |heading| %>
       <a href="#<%= heading.label current %>"><%= heading.plain_html %></a>
-    <%- end -%>
+    <%- end %>
 
-    <%- list_siblings = proc do -%>
-      <%- level = table.first&.level -%>
-      <%- while table.first && table.first.level >= level -%>
-        <%- heading = table.shift -%>
-        <%- if table.first.nil? || table.first.level <= heading.level -%>
-          <li><% display_link.call heading -%>
-        <%- else -%>
+    <%- list_siblings = proc do %>
+      <%- level = table.first&.level %>
+      <%- while table.first && table.first.level >= level %>
+        <%- heading = table.shift %>
+        <%- if table.first.nil? || table.first.level <= heading.level %>
+          <li><% display_link.call heading %></li>
+        <%- else %>
           <li>
             <details open>
-              <summary><%- display_link.call heading -%></summary>
+              <summary><%- display_link.call heading %></summary>
               <ul class="link-list" role="directory">
                 <% list_siblings.call %>
               </ul>
             </details>
           </li>
-        <%- end -%>
-      <%- end -%>
-    <%- end -%>
+        <%- end %>
+      <%- end %>
+    <%- end %>
 
   <ul class="link-list" role="directory">
     <% list_siblings.call %>
   </ul>
 </div>
-<%- end -%>
+<%- end %>
diff --git a/lib/rdoc/generator/template/darkfish/class.rhtml b/lib/rdoc/generator/template/darkfish/class.rhtml
index 628945d886..67a60e3f4e 100644
--- a/lib/rdoc/generator/template/darkfish/class.rhtml
+++ b/lib/rdoc/generator/template/darkfish/class.rhtml
@@ -17,10 +17,10 @@
   <%= render '_footer.rhtml' %>
 </nav>
 
-<main role="main" aria-labelledby="<%=h klass.aref %>">
+<main role="main" aria-labelledby="<%= h klass.aref %>">
   <%# If nesting level is 1, breadcrumb list is not needed %>
   <% if breadcrumb.size > 1 %>
-    <ol role="navigation" aria-label="breadcrumb" class="breadcrumb">
+    <ol role="navigation" aria-label="Breadcrumb navigation" class="breadcrumb">
       <% breadcrumb.each do |namespace| %>
       <li>
         <% if namespace[:self] %>
@@ -33,7 +33,7 @@
     </ol>
   <% end %>
 
-  <h1 id="<%=h klass.aref %>" class="anchor-link <%= klass.type %>">
+  <h1 id="<%= h klass.aref %>" class="anchor-link <%= klass.type %>">
     <%= klass.type %> <%= klass.full_name %>
   </h1>
 
@@ -41,9 +41,9 @@
     <%= klass.description %>
   </section>
 
-  <%- klass.each_section do |section, constants, attributes| -%>
+  <%- klass.each_section do |section, constants, attributes| %>
   <section id="<%= section.aref %>" class="documentation-section anchor-link">
-    <%- if section.title then -%>
+    <%- if section.title then %>
     <header class="documentation-section-title">
       <h2>
         <%= section.title %>
@@ -52,45 +52,46 @@
         <a href="#top">&uarr; top</a>
       </span>
     </header>
-    <%- end -%>
+    <%- end %>
 
-    <%- if section.comment then -%>
+    <%- if section.comment then %>
     <div>
       <%= section.description %>
     </div>
-    <%- end -%>
+    <%- end %>
 
-    <%- unless constants.empty? then -%>
+    <%- unless constants.empty? then %>
     <section class="constants-list">
       <header>
         <h3>Constants</h3>
       </header>
       <dl>
-      <%- constants.each do |const| -%>
-        <dt id="<%= const.name %>"><%= const.name %>
-        <%- if const.comment then -%>
+      <%- constants.each do |const| %>
+        <dt id="<%= const.name %>"><%= const.name %></dt>
+        <%- if const.comment then %>
         <dd>
-          <%- if const.mixin_from then -%>
+          <%- if const.mixin_from then %>
             <div class="mixin-from">
-              Included from <a href="<%= klass.aref_to(const.mixin_from.path)%>"><%= const.mixin_from.full_name %></a>
+              Included from <a href="<%= klass.aref_to(const.mixin_from.path) %>"><%= const.mixin_from.full_name %></a>
             </div>
-          <%- end -%>
+          <%- end %>
           <%= const.description.strip %>
-        <%- else -%>
-        <dd class="missing-docs">(Not documented)
-        <%- end -%>
-      <%- end -%>
+        </dd>
+        <%- else %>
+        <dd class="missing-docs">(Not documented)</dd>
+        <%- end %>
+      <%- end %>
       </dl>
     </section>
-    <%- end -%>
+    <%- end %>
 
-    <%- unless attributes.empty? then -%>
-    <section class="attribute-method-details" class="method-section">
+    <%- unless attributes.empty? then %>
+    <section class="attribute-method-details method-section">
       <header>
         <h3>Attributes</h3>
       </header>
 
-      <%- attributes.each do |attrib| -%>
+      <%- attributes.each do |attrib| %>
       <div id="<%= attrib.aref %>" class="method-detail anchor-link">
         <div class="method-heading attribute-method-heading">
           <a href="#<%= attrib.aref %>" title="Link to this attribute">
@@ -100,21 +101,21 @@
         </div>
 
         <div class="method-description">
-        <%- if attrib.mixin_from then -%>
+        <%- if attrib.mixin_from then %>
           <div class="mixin-from">
-            <%= attrib.singleton ? "Extended" : "Included" %> from <a href="<%= klass.aref_to(attrib.mixin_from.path)%>"><%= attrib.mixin_from.full_name %></a>
+            <%= attrib.singleton ? "Extended" : "Included" %> from <a href="<%= klass.aref_to(attrib.mixin_from.path) %>"><%= attrib.mixin_from.full_name %></a>
           </div>
-        <%- end -%>
-        <%- if attrib.comment then -%>
+        <%- end %>
+        <%- if attrib.comment then %>
         <%= attrib.description.strip %>
-        <%- else -%>
-        <p class="missing-docs">(Not documented)
-        <%- end -%>
+        <%- else %>
+        <p class="missing-docs">(Not documented)</p>
+        <%- end %>
         </div>
       </div>
-      <%- end -%>
+      <%- end %>
     </section>
-    <%- end -%>
+    <%- end %>
 
     <%- klass.methods_by_type(section).each do |type, visibilities|
        next if visibilities.empty?
@@ -125,11 +126,11 @@
          <h3><%= visibility.to_s.capitalize %> <%= type.capitalize %> Methods</h3>
        </header>
 
-    <%- methods.each do |method| -%>
+    <%- methods.each do |method| %>
       <div id="<%= method.aref %>" class="method-detail anchor-link <%= method.is_alias_for ? "method-alias" : '' %>">
         <div class="method-header">
-          <%- if (call_seq = method.call_seq) then -%>
-            <%- call_seq.strip.split("\n").each_with_index do |call_seq, i| -%>
+          <%- if (call_seq = method.call_seq) then %>
+            <%- call_seq.strip.split("\n").each_with_index do |call_seq, i| %>
               <div class="method-heading">
                 <a href="#<%= method.aref %>" title="Link to this method">
                   <span class="method-callseq">
@@ -139,49 +140,49 @@
                   </span>
                 </a>
               </div>
-            <%- end -%>
-          <%- elsif method.has_call_seq? then -%>
+            <%- end %>
+          <%- elsif method.has_call_seq? then %>
             <div class="method-heading">
               <a href="#<%= method.aref %>" title="Link to this method">
                 <span class="method-name"><%= h method.name %></span>
               </a>
             </div>
-          <%- else -%>
+          <%- else %>
             <div class="method-heading">
               <a href="#<%= method.aref %>" title="Link to this method">
                 <span class="method-name"><%= h method.name %></span>
                 <span class="method-args"><%= h method.param_seq %></span>
               </a>
             </div>
-          <%- end -%>
+          <%- end %>
         </div>
 
-        <%- if method.token_stream -%>
+        <%- if method.token_stream %>
           <div class="method-controls">
             <details class="method-source-toggle">
               <summary>Source</summary>
             </details>
           </div>
-        <%- end -%>
+        <%- end %>
 
-        <%- unless method.skip_description? then -%>
+        <%- unless method.skip_description? then %>
         <div class="method-description">
-          <%- if method.token_stream then -%>
+          <%- if method.token_stream then %>
           <div class="method-source-code" id="<%= method.html_name %>-source">
             <pre><%= method.markup_code %></pre>
           </div>
-          <%- end -%>
-          <%- if method.mixin_from then -%>
+          <%- end %>
+          <%- if method.mixin_from then %>
             <div class="mixin-from">
-              <%= method.singleton ? "Extended" : "Included" %> from <a href="<%= klass.aref_to(method.mixin_from.path)%>"><%= method.mixin_from.full_name %></a>
+              <%= method.singleton ? "Extended" : "Included" %> from <a href="<%= klass.aref_to(method.mixin_from.path) %>"><%= method.mixin_from.full_name %></a>
             </div>
-          <%- end -%>
-          <%- if method.comment then -%>
+          <%- end %>
+          <%- if method.comment then %>
           <%= method.description.strip %>
-          <%- else -%>
-          <p class="missing-docs">(Not documented)
-          <%- end -%>
-          <%- if method.calls_super then -%>
+          <%- else %>
+          <p class="missing-docs">(Not documented)</p>
+          <%- end %>
+          <%- if method.calls_super then %>
             <div class="method-calls-super">
               Calls superclass method
               <%=
@@ -189,11 +190,11 @@
                   method.formatter.link(method.superclass_method.full_name, method.superclass_method.full_name) : nil
               %>
             </div>
-          <%- end -%>
+          <%- end %>
         </div>
-        <%- end -%>
+        <%- end %>
 
-        <%- unless method.aliases.empty? then -%>
+        <%- unless method.aliases.empty? then %>
         <div class="aliases">
           Also aliased as: <%= method.aliases.map do |aka|
             if aka.parent then # HACK lib/rexml/encodings
@@ -203,19 +204,20 @@
             end
           end.join ", " %>
         </div>
-        <%- end -%>
+        <%- end %>
 
-        <%- if method.is_alias_for then -%>
+        <%- if method.is_alias_for then %>
         <div class="aliases">
           Alias for: <a href="<%= klass.aref_to method.is_alias_for.path %>"><%= h method.is_alias_for.name %></a>
         </div>
-        <%- end -%>
+        <%- end %>
       </div>
 
-    <%- end -%>
+    <%- end %>
     </section>
   <%- end
      end %>
   </section>
-<%- end -%>
+<%- end %>
 </main>
+</body>
diff --git a/lib/rdoc/generator/template/darkfish/index.rhtml b/lib/rdoc/generator/template/darkfish/index.rhtml
index beaab9570f..d2ebcf69f7 100644
--- a/lib/rdoc/generator/template/darkfish/index.rhtml
+++ b/lib/rdoc/generator/template/darkfish/index.rhtml
@@ -17,7 +17,8 @@
 <main role="main">
 <%- if @main_page %>
   <%= @main_page.description %>
-<%- else -%>
-  <p>This is the API documentation for <%= h @title %>.
-<%- end -%>
+<%- else %>
+  <p>This is the API documentation for <%= h @title %>.</p>
+<%- end %>
 </main>
+</body>
diff --git a/lib/rdoc/generator/template/darkfish/page.rhtml b/lib/rdoc/generator/template/darkfish/page.rhtml
index fb33eba6fd..9c5ae99716 100644
--- a/lib/rdoc/generator/template/darkfish/page.rhtml
+++ b/lib/rdoc/generator/template/darkfish/page.rhtml
@@ -13,6 +13,7 @@
   <%= render '_footer.rhtml' %>
 </nav>
 
-<main role="main" aria-label="Page <%=h file.full_name%>">
+<main role="main" aria-label="Page <%= h file.full_name %>">
 <%= file.description %>
 </main>
+</body>
diff --git a/lib/rdoc/generator/template/darkfish/servlet_not_found.rhtml b/lib/rdoc/generator/template/darkfish/servlet_not_found.rhtml
index 098b589add..a7a63162e1 100644
--- a/lib/rdoc/generator/template/darkfish/servlet_not_found.rhtml
+++ b/lib/rdoc/generator/template/darkfish/servlet_not_found.rhtml
@@ -16,5 +16,6 @@
 <main role="main">
   <h1>Not Found</h1>
 
-  <p><%= message %>
+  <p><%= message %></p>
 </main>
+</body>
diff --git a/lib/rdoc/generator/template/darkfish/servlet_root.rhtml b/lib/rdoc/generator/template/darkfish/servlet_root.rhtml
index 373e0006d9..7785024653 100644
--- a/lib/rdoc/generator/template/darkfish/servlet_root.rhtml
+++ b/lib/rdoc/generator/template/darkfish/servlet_root.rhtml
@@ -20,46 +20,46 @@
   <h1>Local RDoc Documentation</h1>
 
   <p>Here you can browse local documentation from the ruby standard library and
-  your installed gems.
+  your installed gems.</p>
 
-<%- extra_dirs = installed.select { |_, _, _, type,| type == :extra } -%>
-<%- unless extra_dirs.empty? -%>
+<%- extra_dirs = installed.select { |_, _, _, type,| type == :extra } %>
+<%- unless extra_dirs.empty? %>
   <h2>Extra Documentation Directories</h2>
 
   <p>The following additional documentation directories are available:</p>
 
   <ol>
-  <%- extra_dirs.each do |name, href, exists, _, path| -%>
+  <%- extra_dirs.each do |name, href, exists, _, path| %>
     <li>
-    <%- if exists -%>
+    <%- if exists %>
       <a href="<%= href %>"><%= h name %></a> (<%= h path %>)
-    <%- else -%>
+    <%- else %>
       <%= h name %> (<%= h path %>; <i>not available</i>)
-    <%- end -%>
+    <%- end %>
     </li>
-  <%- end -%>
+  <%- end %>
   </ol>
-<%- end -%>
+<%- end %>
 
-<%- gems = installed.select { |_, _, _, type,| type == :gem } -%>
-<%- missing = gems.reject { |_, _, exists,| exists } -%>
-<%- unless missing.empty? then -%>
+<%- gems = installed.select { |_, _, _, type,| type == :gem } %>
+<%- missing = gems.reject { |_, _, exists,| exists } %>
+<%- unless missing.empty? %>
   <h2>Missing Gem Documentation</h2>
 
   <p>You are missing documentation for some of your installed gems.
   You can install missing documentation for gems by running
   <kbd>gem rdoc --all</kbd>.  After installing the missing documentation you
   only need to reload this page.  The newly created documentation will
-  automatically appear.
+  automatically appear.</p>
 
   <p>You can also install documentation for a specific gem by running one of
-  the following commands.
+  the following commands.</p>
 
   <ul>
-  <%- names = missing.map { |name,| name.sub(/-([^-]*)$/, '') }.uniq -%>
-  <%- names.each do |name| -%>
-    <li><kbd>gem rdoc <%=h name %></kbd>
-  <%- end -%>
+  <%- missing.map { |name,| name.sub(/-([^-]*)$/, '') }.uniq.each do |name| %>
+    <li><kbd>gem rdoc <%= h name %></kbd></li>
+  <%- end %>
   </ul>
-<%- end -%>
+<%- end %>
 </main>
+</body>
diff --git a/lib/rdoc/generator/template/darkfish/table_of_contents.rhtml b/lib/rdoc/generator/template/darkfish/table_of_contents.rhtml
index 2cd2207836..7cd8da15d9 100644
--- a/lib/rdoc/generator/template/darkfish/table_of_contents.rhtml
+++ b/lib/rdoc/generator/template/darkfish/table_of_contents.rhtml
@@ -13,11 +13,11 @@
 <main role="main">
 <h1 class="class"><%= h @title %></h1>
 
-<%- simple_files = @files.select { |f| f.text? } -%>
-<%- unless simple_files.empty? then -%>
+<%- simple_files = @files.select { |f| f.text? } %>
+<%- unless simple_files.empty? then %>
 <h2 id="pages">Pages</h2>
 <ul>
-<%- simple_files.sort.each do |file| -%>
+<%- simple_files.sort.each do |file| %>
   <li class="file">
     <a href="<%= h file.path %>"><%= h file.page_name %></a>
 <%
@@ -25,19 +25,19 @@
    table = file.parse(file.comment).table_of_contents
    unless table.empty? then %>
     <ul>
-<%- table.each do |heading| -%>
-      <li><a href="<%= h file.path %>#<%= heading.aref %>"><%= heading.plain_html %></a>
-<%-   end -%>
+    <%- table.each do |heading| %>
+      <li><a href="<%= h file.path %>#<%= heading.aref %>"><%= heading.plain_html %></a></li>
+    <%- end %>
     </ul>
-<%- end -%>
+<%- end %>
   </li>
-  <%- end -%>
+  <%- end %>
 </ul>
-<%- end -%>
+<%- end %>
 
 <h2 id="classes">Classes and Modules</h2>
 <ul>
-<%- @modsort.each do |klass| -%>
+<%- @modsort.each do |klass| %>
   <li class="<%= klass.type %>">
     <a href="<%= klass.path %>"><%= klass.full_name %></a>
 <%- table = []
@@ -46,14 +46,14 @@
 
    unless table.empty? then %>
     <ul>
-<%- table.each do |item| -%>
-<%-   label = item.respond_to?(:label) ? item.label(klass) : item.aref -%>
-      <li><a href="<%= klass.path %>#<%= label %>"><%= item.plain_html %></a>
-<%- end -%>
+<%- table.each do |item| %>
+<%-   label = item.respond_to?(:label) ? item.label(klass) : item.aref %>
+      <li><a href="<%= klass.path %>#<%= label %>"><%= item.plain_html %></a></li>
+<%- end %>
     </ul>
-<%- end -%>
+<%- end %>
   </li>
-<%- end -%>
+<%- end %>
 </ul>
 
 <h2 id="methods">Methods</h2>
@@ -65,6 +65,8 @@
     <a href="<%= method.path %>"><%= h method.pretty_name %></a>
     &mdash;
     <span class="container"><%= method.parent.full_name %></span>
-<%- end -%>
+  </li>
+<%- end %>
 </ul>
 </main>
+</body>
diff --git a/test/rdoc/rdoc_generator_darkfish_test.rb b/test/rdoc/rdoc_generator_darkfish_test.rb
index 80c2bf0c44..fd13c8cc69 100644
--- a/test/rdoc/rdoc_generator_darkfish_test.rb
+++ b/test/rdoc/rdoc_generator_darkfish_test.rb
@@ -121,7 +121,7 @@ def test_generate
       klassnav
     )
     assert_match(
-      %r[<li>\s*<a href=\S+>Heading 1.1.1.1</a>\s*</ul>\s*</details>\s*</li>]m,
+      %r[<li>\s*<a href=\S+>Heading 1.1.1.1</a>\s*</li>\s*</ul>\s*</details>\s*</li>]m,
       klassnav
     )