diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 66f888a1c2b..28cb8ae48e2 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -1080,8 +1080,11 @@ body.blur > :not(#help) {
 
 .impl-items .srclink, .impl .srclink, .methods .srclink {
 	/* Override header settings otherwise it's too bold */
-	font-size: 1.0625rem;
 	font-weight: normal;
+	font-size: 1rem;
+}
+.impl .srclink {
+	font-size: 1.0625rem;
 }
 
 .rightside {
diff --git a/src/librustdoc/html/static/css/themes/ayu.css b/src/librustdoc/html/static/css/themes/ayu.css
index 38040eeca52..6ed7845e83a 100644
--- a/src/librustdoc/html/static/css/themes/ayu.css
+++ b/src/librustdoc/html/static/css/themes/ayu.css
@@ -351,11 +351,8 @@ a.test-arrow:hover {
 	color: #999;
 }
 
-:target, :target > * {
-	background: rgba(255, 236, 164, 0.06);
-}
-
 :target {
+	background: rgba(255, 236, 164, 0.06);
 	border-right: 3px solid rgba(255, 180, 76, 0.85);
 }
 
diff --git a/src/librustdoc/html/static/css/themes/dark.css b/src/librustdoc/html/static/css/themes/dark.css
index f4181e431c8..64b6eb6696b 100644
--- a/src/librustdoc/html/static/css/themes/dark.css
+++ b/src/librustdoc/html/static/css/themes/dark.css
@@ -295,11 +295,8 @@ a.test-arrow:hover{
 	color: #999;
 }
 
-:target, :target > * {
-	background-color: #494a3d;
-}
-
 :target {
+	background-color: #494a3d;
 	border-right: 3px solid #bb7410;
 }
 
diff --git a/src/librustdoc/html/static/css/themes/light.css b/src/librustdoc/html/static/css/themes/light.css
index 176f63098a4..dbacc9f3073 100644
--- a/src/librustdoc/html/static/css/themes/light.css
+++ b/src/librustdoc/html/static/css/themes/light.css
@@ -284,11 +284,8 @@ a.test-arrow:hover{
 	color: #999;
 }
 
-:target, :target > * {
-	background: #FDFFD3;
-}
-
 :target {
+	background: #FDFFD3;
 	border-right: 3px solid #AD7C37;
 }
 
diff --git a/src/test/rustdoc-gui/src-font-size.goml b/src/test/rustdoc-gui/src-font-size.goml
new file mode 100644
index 00000000000..b0b2f122afd
--- /dev/null
+++ b/src/test/rustdoc-gui/src-font-size.goml
@@ -0,0 +1,12 @@
+// This test ensures that the "[src]" have the same font size as their headers
+// to avoid having some weird height difference in the background when the element
+// is selected.
+goto: file://|DOC_PATH|/test_docs/struct.Foo.html
+show-text: true
+// Check the impl headers.
+assert-css: (".impl.has-srclink .srclink", {"font-size": "17px"}, ALL)
+// The ".6" part is because the font-size is actually "1.1em".
+assert-css: (".impl.has-srclink .code-header.in-band", {"font-size": "17.6px"}, ALL)
+// Check the impl items.
+assert-css: (".impl-items .has-srclink .srclink", {"font-size": "16px"}, ALL)
+assert-css: (".impl-items .has-srclink .code-header", {"font-size": "16px"}, ALL)