Fix highlighting in notable tooltip

Author: notriddle

src/librustdoc/html/static/css/themes/ayu.css

@@ -334,7 +334,7 @@ a.test-arrow:hover {
 	color: #999;
 }
 
-:target, :target * {
+:target, :target > * {
 	background: rgba(255, 236, 164, 0.06);
 }
 

src/librustdoc/html/static/css/themes/dark.css

@@ -282,7 +282,7 @@ a.test-arrow:hover{
 	color: #999;
 }
 
-:target, :target * {
+:target, :target > * {
 	background-color: #494a3d;
 }
 

src/librustdoc/html/static/css/themes/light.css

@@ -274,7 +274,7 @@ a.test-arrow:hover{
 	color: #999;
 }
 
-:target, :target * {
+:target, :target > * {
 	background: #FDFFD3;
 }