Make subtitle more readable - larger and not italic

- Increased font size from 1.375rem to 1.5rem (24px)
- Changed color from muted to secondary (brighter)
- Removed italic style for better readability

style.css

@@ -88,11 +88,11 @@ body {
 
 /* Subtitle styling */
 #content h1 + p {
-    font-size: 1.375rem;
-    color: var(--text-muted);
+    font-size: 1.5rem;
+    color: var(--text-secondary);
     font-weight: 500;
     margin-bottom: 2.5rem;
-    font-style: italic;
+    font-style: normal;
 }
 
 #content h2 {