Fix display of toggles on mobile

Author: GuillaumeGomez

src/librustdoc/html/static/css/rustdoc.css

@@ -2007,6 +2007,16 @@ details.rustdoc-toggle[open] > summary.hideme::after {
 		max-width: 100vw;
 		width: 100vw;
 	}
+
+	/* Position of the "[-]" element. */
+	details.rustdoc-toggle:not(.top-doc) > summary {
+		margin-left: 10px;
+	}
+	.impl-items > details.rustdoc-toggle > summary:not(.hideme)::before,
+	#main-content > details.rustdoc-toggle:not(.top-doc) > summary::before,
+	#main-content > div > details.rustdoc-toggle > summary::before {
+		left: -11px;
+	}
 }
 
 @media print {

src/test/rustdoc-gui/toggle-docs-mobile.goml

@@ -9,6 +9,16 @@ assert-attribute: (".top-doc", {"open": ""})
 click: (3, 280)
 assert-attribute: (".top-doc", {"open": ""})
 
+// Assert the position of the toggle on the top doc block.
+assert-position: (".top-doc summary::before", {"x": 4})
+// Assert the position of the toggle on the impl block.
+assert-position: ("#implementations + details > summary::before", {"x": 4})
+// Assert the position of the toggle on a method.
+assert-position: (
+    "#trait-implementations-list .impl-items .method-toggle > summary::before",
+    {"x": 4},
+)
+
 // Now we do the same but with a little bigger width
 size: (600, 600)
 assert-attribute: (".top-doc", {"open": ""})