feat: draw attention to sign link

sass/main.scss

@@ -487,3 +487,18 @@ ul.language-select > li {
 .footnote-definition > p {
 	display: inline;
 }
+
+.nav__link {
+	text-decoration: underline;
+	text-decoration-color: red;
+	text-decoration-thickness: 3px;
+	font-weight: bold;
+	font-size: 1.2em;
+	padding: 10px;
+}
+
+.nav__link:hover,
+.nav__link:active {
+	color: #a31d1d;
+	border-bottom: none !important;
+}