Rollup merge of #99812 - GuillaumeGomez:fix-headings-colors, r=jsha,notriddle

Fix headings colors

Fixes #99797.

![image](https://user-images.githubusercontent.com/3050060/181260966-49faf9d3-f6b8-4de4-bc7d-ed9f0467cf68.png)

cc `@jsha`
r? `@notriddle`

2 files changed, 2 insertions, 6 deletions

diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 02515771349..aecc9aa879a 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -167,7 +167,7 @@ h2, h3, h4 {
 h2,
 .top-doc .docblock > h3,
 .top-doc .docblock > h4 {
-	border-bottom: 1px solid;
+	border-bottom: 1px solid var(--headings-border-bottom-color);
 }
 h3.code-header {
 	font-size: 1.125rem; /* 18px */
@@ -652,7 +652,7 @@ h2.location a {
 }
 
 .top-doc .docblock h2 { font-size: 1.375rem; }
-.top-doc .docblock h3 { font-size: 1.25; }
+.top-doc .docblock h3 { font-size: 1.25rem; }
 .top-doc .docblock h4,
 .top-doc .docblock h5 {
 	font-size: 1.125rem;
diff --git a/src/librustdoc/html/static/css/themes/dark.css b/src/librustdoc/html/static/css/themes/dark.css
index 62d9eaa02e6..a550eb1c130 100644
--- a/src/librustdoc/html/static/css/themes/dark.css
+++ b/src/librustdoc/html/static/css/themes/dark.css
@@ -42,10 +42,6 @@ input:focus + .slider {
 	background-color: #0a042f !important;
 }
 
-.docblock h1, .docblock h2, .docblock h3, .docblock h4, .docblock h5, .docblock h6 {
-	border-bottom-color: #DDD;
-}
-
 .docblock table td, .docblock table th {
 	border-color: #ddd;
 }