fix(html): resolve validation errors, implement dynamic MDX heading shifting, and improve accessibility

components/blog/SplitHeading.tsx

@@ -8,15 +8,17 @@ interface SplitHeadingProps {
   id?: string;
 }
 
-export default function SplitHeading({ children, className = '', id }: SplitHeadingProps) {
+export default function SplitHeading({
+  children,
+  className = '',
+  id,
+  level: Level = 'h2',
+}: SplitHeadingProps & { level?: any }) {
   return (
-    <div 
-      id={id}
-      className={className}
-    >
-      <h2 className="text-xl md:text-2xl font-bold leading-tight text-text-primary">
+    <div id={id} className={className}>
+      <Level className="text-xl md:text-2xl font-bold leading-tight text-text-primary">
         {children}
-      </h2>
+      </Level>
     </div>
   );
 }