diff --git a/src/librustdoc/html/markdown.rs b/src/librustdoc/html/markdown.rs
index 91733004e44c3..4170c73b24625 100644
--- a/src/librustdoc/html/markdown.rs
+++ b/src/librustdoc/html/markdown.rs
@@ -1442,7 +1442,6 @@ static DEFAULT_ID_MAP: Lazy<FxHashMap<Cow<'static, str>, usize>> = Lazy::new(||
 fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     let mut map = FxHashMap::default();
     // This is the list of IDs used in Javascript.
-    map.insert("help".into(), 1);
     map.insert("settings".into(), 1);
     map.insert("not-displayed".into(), 1);
     map.insert("alternative-display".into(), 1);
@@ -1455,7 +1454,6 @@ fn init_id_map() -> FxHashMap<Cow<'static, str>, usize> {
     map.insert("help-button".into(), 1);
     map.insert("main-content".into(), 1);
     map.insert("crate-search".into(), 1);
-    map.insert("render-detail".into(), 1);
     map.insert("toggle-all-docs".into(), 1);
     map.insert("all-types".into(), 1);
     map.insert("default-settings".into(), 1);
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index e8f069cdbfe0c..c6933a8254bc2 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -1733,13 +1733,12 @@ details.rustdoc-toggle[open] > summary.hideme > span {
 	display: none;
 }
 
-details.undocumented[open] > summary::before,
 details.rustdoc-toggle[open] > summary::before,
 details.rustdoc-toggle[open] > summary.hideme::before {
 	background-image: /* AUTOREPLACE: */url("toggle-minus.svg");
 }
 
-details.undocumented > summary::before, details.rustdoc-toggle > summary::before {
+details.rustdoc-toggle > summary::before {
 	background-image: /* AUTOREPLACE: */url("toggle-plus.svg");
 }
 
diff --git a/src/librustdoc/html/static/css/themes/ayu.css b/src/librustdoc/html/static/css/themes/ayu.css
index 73d18df76561b..142ce456c5213 100644
--- a/src/librustdoc/html/static/css/themes/ayu.css
+++ b/src/librustdoc/html/static/css/themes/ayu.css
@@ -174,13 +174,11 @@ body.source .example-wrap pre.rust a {
 }
 
 details.rustdoc-toggle > summary.hideme > span,
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	color: #999;
 }
 
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	filter: invert(100%);
 }
 
@@ -218,17 +216,6 @@ details.undocumented > summary::before {
 	background: none;
 }
 
-#help > div {
-	background: #14191f;
-	box-shadow: 0px 6px 20px 0px black;
-	border: none;
-	border-radius: 4px;
-}
-
-#help span.bottom, #help span.top {
-	border-color: #5c6773;
-}
-
 .rightside,
 .out-of-band {
 	color: grey;
diff --git a/src/librustdoc/html/static/css/themes/dark.css b/src/librustdoc/html/static/css/themes/dark.css
index 93dca51307f58..aeaca7515f962 100644
--- a/src/librustdoc/html/static/css/themes/dark.css
+++ b/src/librustdoc/html/static/css/themes/dark.css
@@ -148,13 +148,11 @@ body.source .example-wrap pre.rust a {
 }
 
 details.rustdoc-toggle > summary.hideme > span,
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	color: #999;
 }
 
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	filter: invert(100%);
 }
 
@@ -179,20 +177,6 @@ details.undocumented > summary::before {
 .stab.portability { background: #F3DFFF; border-color: #b07bdb; color: #2f2f2f; }
 .stab.portability > code { background: none; }
 
-#help > div {
-	background: #4d4d4d;
-	border-color: #bfbfbf;
-}
-
-#help span.bottom, #help span.top {
-	border-color: #bfbfbf;
-}
-
-#help dt {
-	border-color: #bfbfbf;
-	background: rgba(0,0,0,0);
-}
-
 .rightside,
 .out-of-band {
 	color: grey;
diff --git a/src/librustdoc/html/static/css/themes/light.css b/src/librustdoc/html/static/css/themes/light.css
index 73731bc8f9ff3..54d1a7b65d665 100644
--- a/src/librustdoc/html/static/css/themes/light.css
+++ b/src/librustdoc/html/static/css/themes/light.css
@@ -140,8 +140,7 @@ body.source .example-wrap pre.rust a {
 }
 
 details.rustdoc-toggle > summary.hideme > span,
-details.rustdoc-toggle > summary::before,
-details.undocumented > summary::before {
+details.rustdoc-toggle > summary::before {
 	color: #999;
 }
 
@@ -161,15 +160,6 @@ details.undocumented > summary::before {
 .stab.portability { background: #F3DFFF; border-color: #b07bdb; }
 .stab.portability > code { background: none; }
 
-#help > div {
-	background: #e9e9e9;
-	border-color: #bfbfbf;
-}
-
-#help span.bottom, #help span.top {
-	border-color: #bfbfbf;
-}
-
 .rightside,
 .out-of-band {
 	color: grey;