Rollup merge of #84376 - torhovland:issue-84534, r=GuillaumeGomez

Uses flex to fix formatting of h1 at any width

Fixes #84354.

src/librustdoc/html/static/rustdoc.css

@@ -116,6 +116,8 @@ h4:not(.method):not(.type):not(.tymethod):not(.associatedconstant) {
 	padding-bottom: 6px;
 }
 h1.fqn {
+	display: flex;
+	width: 100%;
 	border-bottom: 1px dashed;
 	margin-top: 0;
 }
@@ -458,6 +460,13 @@ nav.sub {
 	font-weight: normal;
 }
 
+h1.fqn > .out-of-band {
+	float: unset;
+	flex: 1;
+	text-align: right;
+	margin-left: 8px;
+}
+
 h3.impl > .out-of-band {
 	font-size: 21px;
 }
@@ -1450,10 +1459,6 @@ h4 > .notable-traits {
 		padding: 0;
 	}
 
-	.content .in-band {
-		width: 100%;
-	}
-
 	.content h4 > .out-of-band {
 		position: inherit;
 	}