fix: 🐛 display style of headings

Signed-off-by: WaitSpring <me@waitspring.com>

resources/skins.citizen.styles/skinning/elements.less

@@ -81,12 +81,12 @@ h6 {
 
 h3,
 h4 {
-	margin-top: 1.5em;
+	margin-top: 1.25em;
 }
 
 h5,
 h6 {
-	margin-top: 1.25em;
+	margin-top: 1em;
 }
 
 h1 {
@@ -94,9 +94,13 @@ h1 {
 	font-size: var( --font-size-h1 );
 }
 
+h1:not( .firstHeading ) {
+	border-bottom: 1px solid var( --border-color-base );
+}
+
 h2 {
 	border-bottom: 1px solid var( --border-color-base );
-	margin-top: 1.75em;
+	margin-top: 0.5em;
 	font-size: var( --font-size-h2 );
 }