diff --git a/lib/rdoc/generator/template/aliki/css/rdoc.css b/lib/rdoc/generator/template/aliki/css/rdoc.css
index 25a3f43076..8341a4ff37 100644
--- a/lib/rdoc/generator/template/aliki/css/rdoc.css
+++ b/lib/rdoc/generator/template/aliki/css/rdoc.css
@@ -70,6 +70,8 @@
   --color-accent-subtle: var(--color-primary-50);
   --color-code-bg: #f6f8fa;
   --color-code-border: var(--color-neutral-300);
+  --color-sig-bg: var(--color-neutral-100);
+  --color-sig-border: var(--color-primary-200);
   --color-nav-bg: #fff;
   --color-nav-text: var(--color-neutral-700);
   --color-th-background: var(--color-neutral-100);
@@ -203,6 +205,8 @@
   --color-accent-subtle-hover: rgb(235 84 79 / 20%);
   --color-code-bg: var(--color-neutral-800);
   --color-code-border: var(--color-neutral-700);
+  --color-sig-bg: #211f1e; /* between neutral-900 and neutral-800 */
+  --color-sig-border: var(--color-accent-primary);
   --color-nav-bg: var(--color-neutral-900);
   --color-nav-text: var(--color-neutral-50);
   --color-th-background: var(--color-background-tertiary);
@@ -1282,6 +1286,7 @@ main .method-description .method-calls-super {
 }
 
 main .method-detail {
+  position: relative;
   margin-bottom: 2.5em;
 }
 
@@ -1292,16 +1297,34 @@ main .method-detail:target {
 }
 
 main .method-header {
-  display: inline-block;
-  max-width: calc(100% - 6em); /* 6em is the width of the source code toggle */
+  background: var(--color-sig-bg);
+  border-left: 3px solid var(--color-sig-border);
+  border-radius: var(--radius-md);
+  padding: var(--space-3);
+  padding-right: 6em;
 }
 
 main .method-heading {
-  position: relative;
+  display: flex;
+  flex-direction: column;
+  align-items: flex-start;
   font-family: var(--font-code);
   font-size: var(--font-size-lg);
   font-weight: var(--font-weight-semibold);
-  margin-bottom: var(--space-3);
+  line-height: var(--line-height-normal);
+}
+
+main .method-heading a {
+  color: inherit;
+  text-decoration: none;
+}
+
+main .method-heading a:hover {
+  color: var(--color-accent-primary);
+}
+
+main .method-heading .method-callseq {
+  display: block;
 }
 
 main .method-heading .method-name {
@@ -1313,7 +1336,9 @@ main .method-heading .method-args {
 }
 
 main .method-controls {
-  float: right;
+  position: absolute;
+  top: var(--space-3);
+  right: var(--space-3);
 }
 
 main .method-controls summary {
@@ -1356,14 +1381,19 @@ main .method-controls summary:active {
   border-color: var(--color-primary-500);
 }
 
-main .method-description,
-main .aliases {
-  margin-top: 0.75em;
+main .method-description {
   color: var(--color-text-primary);
+  line-height: var(--line-height-relaxed);
+}
+
+main .method-header ~ .method-description {
+  margin-top: var(--space-5);
+  padding-left: var(--space-2);
 }
 
 main .aliases {
-  padding-top: 4px;
+  margin-top: var(--space-4);
+  padding-top: var(--space-1);
   font-style: italic;
   cursor: default;
 }
@@ -1410,9 +1440,18 @@ main .attribute-access-type {
     white-space: nowrap;
   }
 
+  main .method-heading {
+    font-size: var(--font-size-base);
+  }
+
+  main .method-header {
+    padding: var(--space-2);
+    padding-right: var(--space-2);
+  }
+
   main .method-controls {
-    margin-top: 10px;
-    float: none;
+    position: static;
+    margin-top: var(--space-2);
   }
 }
 
diff --git a/lib/rdoc/markdown.kpeg b/lib/rdoc/markdown.kpeg
index d95a88a823..8d24cc097f 100644
--- a/lib/rdoc/markdown.kpeg
+++ b/lib/rdoc/markdown.kpeg
@@ -1249,7 +1249,7 @@ RawNoteBlock = @StartList:a
 # Markdown extensions added by RDoc follow
 
 CodeFence = &{ github? }
-            Ticks3 (@Sp StrChunk:format)? Spnl < (
+            Ticks3 (@Sp StrChunk:format)? @Sp @Newline? < (
               ( !"`" Nonspacechar )+ |
               !Ticks3 /`+/ |
               Spacechar |
diff --git a/lib/rdoc/markdown.rb b/lib/rdoc/markdown.rb
index e4d0ae9ff6..45954fd1cc 100644
--- a/lib/rdoc/markdown.rb
+++ b/lib/rdoc/markdown.rb
@@ -15570,7 +15570,7 @@ def _RawNoteBlock
     return _tmp
   end
 
-  # CodeFence = &{ github? } Ticks3 (@Sp StrChunk:format)? Spnl < ((!"`" Nonspacechar)+ | !Ticks3 /`+/ | Spacechar | @Newline)+ > Ticks3 @Sp @Newline* { verbatim = RDoc::Markup::Verbatim.new text               verbatim.format = format.intern if format.instance_of?(String)               verbatim             }
+  # CodeFence = &{ github? } Ticks3 (@Sp StrChunk:format)? @Sp @Newline? < ((!"`" Nonspacechar)+ | !Ticks3 /`+/ | Spacechar | @Newline)+ > Ticks3 @Sp @Newline* { verbatim = RDoc::Markup::Verbatim.new text               verbatim.format = format.intern if format.instance_of?(String)               verbatim             }
   def _CodeFence
 
     _save = self.pos
@@ -15612,31 +15612,41 @@ def _CodeFence
         self.pos = _save
         break
       end
-      _tmp = apply(:_Spnl)
+      _tmp = _Sp()
       unless _tmp
         self.pos = _save
         break
       end
-      _text_start = self.pos
       _save4 = self.pos
-
+      _tmp = _Newline()
+      unless _tmp
+        _tmp = true
+        self.pos = _save4
+      end
+      unless _tmp
+        self.pos = _save
+        break
+      end
+      _text_start = self.pos
       _save5 = self.pos
-      while true # choice
-        _save6 = self.pos
 
+      _save6 = self.pos
+      while true # choice
         _save7 = self.pos
+
+        _save8 = self.pos
         while true # sequence
-          _save8 = self.pos
+          _save9 = self.pos
           _tmp = match_string("`")
           _tmp = _tmp ? nil : true
-          self.pos = _save8
+          self.pos = _save9
           unless _tmp
-            self.pos = _save7
+            self.pos = _save8
             break
           end
           _tmp = apply(:_Nonspacechar)
           unless _tmp
-            self.pos = _save7
+            self.pos = _save8
           end
           break
         end # end sequence
@@ -15644,19 +15654,19 @@ def _CodeFence
         if _tmp
           while true
 
-            _save9 = self.pos
+            _save10 = self.pos
             while true # sequence
-              _save10 = self.pos
+              _save11 = self.pos
               _tmp = match_string("`")
               _tmp = _tmp ? nil : true
-              self.pos = _save10
+              self.pos = _save11
               unless _tmp
-                self.pos = _save9
+                self.pos = _save10
                 break
               end
               _tmp = apply(:_Nonspacechar)
               unless _tmp
-                self.pos = _save9
+                self.pos = _save10
               end
               break
             end # end sequence
@@ -15665,59 +15675,59 @@ def _CodeFence
           end
           _tmp = true
         else
-          self.pos = _save6
+          self.pos = _save7
         end
         break if _tmp
-        self.pos = _save5
+        self.pos = _save6
 
-        _save11 = self.pos
+        _save12 = self.pos
         while true # sequence
-          _save12 = self.pos
+          _save13 = self.pos
           _tmp = apply(:_Ticks3)
           _tmp = _tmp ? nil : true
-          self.pos = _save12
+          self.pos = _save13
           unless _tmp
-            self.pos = _save11
+            self.pos = _save12
             break
           end
           _tmp = scan(/\G(?-mix:`+)/)
           unless _tmp
-            self.pos = _save11
+            self.pos = _save12
           end
           break
         end # end sequence
 
         break if _tmp
-        self.pos = _save5
+        self.pos = _save6
         _tmp = apply(:_Spacechar)
         break if _tmp
-        self.pos = _save5
+        self.pos = _save6
         _tmp = _Newline()
         break if _tmp
-        self.pos = _save5
+        self.pos = _save6
         break
       end # end choice
 
       if _tmp
         while true
 
-          _save13 = self.pos
+          _save14 = self.pos
           while true # choice
-            _save14 = self.pos
-
             _save15 = self.pos
+
+            _save16 = self.pos
             while true # sequence
-              _save16 = self.pos
+              _save17 = self.pos
               _tmp = match_string("`")
               _tmp = _tmp ? nil : true
-              self.pos = _save16
+              self.pos = _save17
               unless _tmp
-                self.pos = _save15
+                self.pos = _save16
                 break
               end
               _tmp = apply(:_Nonspacechar)
               unless _tmp
-                self.pos = _save15
+                self.pos = _save16
               end
               break
             end # end sequence
@@ -15725,19 +15735,19 @@ def _CodeFence
             if _tmp
               while true
 
-                _save17 = self.pos
+                _save18 = self.pos
                 while true # sequence
-                  _save18 = self.pos
+                  _save19 = self.pos
                   _tmp = match_string("`")
                   _tmp = _tmp ? nil : true
-                  self.pos = _save18
+                  self.pos = _save19
                   unless _tmp
-                    self.pos = _save17
+                    self.pos = _save18
                     break
                   end
                   _tmp = apply(:_Nonspacechar)
                   unless _tmp
-                    self.pos = _save17
+                    self.pos = _save18
                   end
                   break
                 end # end sequence
@@ -15746,36 +15756,36 @@ def _CodeFence
               end
               _tmp = true
             else
-              self.pos = _save14
+              self.pos = _save15
             end
             break if _tmp
-            self.pos = _save13
+            self.pos = _save14
 
-            _save19 = self.pos
+            _save20 = self.pos
             while true # sequence
-              _save20 = self.pos
+              _save21 = self.pos
               _tmp = apply(:_Ticks3)
               _tmp = _tmp ? nil : true
-              self.pos = _save20
+              self.pos = _save21
               unless _tmp
-                self.pos = _save19
+                self.pos = _save20
                 break
               end
               _tmp = scan(/\G(?-mix:`+)/)
               unless _tmp
-                self.pos = _save19
+                self.pos = _save20
               end
               break
             end # end sequence
 
             break if _tmp
-            self.pos = _save13
+            self.pos = _save14
             _tmp = apply(:_Spacechar)
             break if _tmp
-            self.pos = _save13
+            self.pos = _save14
             _tmp = _Newline()
             break if _tmp
-            self.pos = _save13
+            self.pos = _save14
             break
           end # end choice
 
@@ -15783,7 +15793,7 @@ def _CodeFence
         end
         _tmp = true
       else
-        self.pos = _save4
+        self.pos = _save5
       end
       if _tmp
         text = get_text(_text_start)
@@ -16677,7 +16687,7 @@ def _DefinitionListDefinition
   Rules[:_InlineNote] = rule_info("InlineNote", "&{ notes? } \"^[\" @StartList:a (!\"]\" Inline:l { a << l })+ \"]\" { ref = [:inline, @note_order.length]                @footnotes[ref] = paragraph a                 note_for ref              }")
   Rules[:_Notes] = rule_info("Notes", "(Note | SkipBlock)*")
   Rules[:_RawNoteBlock] = rule_info("RawNoteBlock", "@StartList:a (!@BlankLine !RawNoteReference OptionallyIndentedLine:l { a << l })+ < @BlankLine* > { a << text } { a }")
-  Rules[:_CodeFence] = rule_info("CodeFence", "&{ github? } Ticks3 (@Sp StrChunk:format)? Spnl < ((!\"`\" Nonspacechar)+ | !Ticks3 /`+/ | Spacechar | @Newline)+ > Ticks3 @Sp @Newline* { verbatim = RDoc::Markup::Verbatim.new text               verbatim.format = format.intern if format.instance_of?(String)               verbatim             }")
+  Rules[:_CodeFence] = rule_info("CodeFence", "&{ github? } Ticks3 (@Sp StrChunk:format)? @Sp @Newline? < ((!\"`\" Nonspacechar)+ | !Ticks3 /`+/ | Spacechar | @Newline)+ > Ticks3 @Sp @Newline* { verbatim = RDoc::Markup::Verbatim.new text               verbatim.format = format.intern if format.instance_of?(String)               verbatim             }")
   Rules[:_Table] = rule_info("Table", "&{ github? } TableHead:header TableLine:line TableRow+:body {           table = RDoc::Markup::Table.new(header, line, body)           parse_table_cells(table)         }")
   Rules[:_TableHead] = rule_info("TableHead", "TableItem2+:items \"|\"? @Newline { items }")
   Rules[:_TableRow] = rule_info("TableRow", "((TableItem:item1 TableItem2+:items { [item1, *items] }):row | TableItem2+:row) \"|\"? @Newline { row }")
diff --git a/test/rdoc/rdoc_markdown_test.rb b/test/rdoc/rdoc_markdown_test.rb
index fc96b2985c..5ffed64f78 100644
--- a/test/rdoc/rdoc_markdown_test.rb
+++ b/test/rdoc/rdoc_markdown_test.rb
@@ -1242,6 +1242,21 @@ def test_code_fence_with_unintended_array
     assert_equal expected, doc
   end
 
+  def test_code_fence_preserves_text_indentation
+    doc = parse <<~MD
+    ```ruby
+      foo()
+      bar()
+    ```
+    MD
+
+    expected = doc(
+      verb("  foo()\n  bar()\n").tap { |v| v.format = :ruby }
+    )
+
+    assert_equal expected, doc
+  end
+
   def test_gfm_table
     doc = parse <<~MD
     |      |                 |compare-ruby|built-ruby|