fix(blog): table of contents scroll links

Fixes an issue where TOC links wouldn't scroll due to

ID generation mismatches on MDX headers containing

formatted text or German umlauts.

components/blog/MDXComponents.tsx

@@ -10,6 +10,7 @@ import PowerCTA from '@/components/blog/PowerCTA';
 import StickyNarrative from '@/components/blog/StickyNarrative';
 import TechnicalGrid from '@/components/blog/TechnicalGrid';
 import ComparisonGrid from '@/components/blog/ComparisonGrid';
+import { generateHeadingId, getTextContent } from '@/lib/blog';
 
 export const mdxComponents = {
   VisualLinkPreview,
@@ -36,17 +37,28 @@ export const mdxComponents = {
           className="inline-flex items-center gap-3 px-6 py-3 bg-primary text-white font-bold rounded-xl hover:bg-accent hover:text-primary-dark transition-all duration-300 no-underline my-8 group shadow-lg hover:shadow-xl hover:-translate-y-1"
         >
           <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 10v6m0 0l-3-3m3 3l3-3m2 8H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z" />
+            <path
+              strokeLinecap="round"
+              strokeLinejoin="round"
+              strokeWidth={2}
+              d="M12 10v6m0 0l-3-3m3 3l3-3m2 8H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"
+            />
           </svg>
           <span>{children}</span>
-          <span className="text-xs opacity-50 font-normal group-hover:opacity-100 transition-opacity">(PDF)</span>
+          <span className="text-xs opacity-50 font-normal group-hover:opacity-100 transition-opacity">
+            (PDF)
+          </span>
         </a>
       );
     }
 
     if (href?.startsWith('/')) {
       return (
-        <Link href={href} {...props} className="text-primary font-medium hover:underline decoration-2 underline-offset-2 transition-all">
+        <Link
+          href={href}
+          {...props}
+          className="text-primary font-medium hover:underline decoration-2 underline-offset-2 transition-all"
+        >
           {children}
         </Link>
       );
@@ -61,18 +73,19 @@ export const mdxComponents = {
       >
         {children}
         <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M10 6H6a2 2 0 00-2 2v10a2 2 0 002 2h10a2 2 0 002-2v-4M14 4h6m0 0v6m0-6L10 14" />
+          <path
+            strokeLinecap="round"
+            strokeLinejoin="round"
+            strokeWidth={2}
+            d="M10 6H6a2 2 0 00-2 2v10a2 2 0 002 2h10a2 2 0 002-2v-4M14 4h6m0 0v6m0-6L10 14"
+          />
         </svg>
       </a>
     );
   },
-  img: (props: any) => (
-    <AnimatedImage src={props.src} alt={props.alt} />
-  ),
+  img: (props: any) => <AnimatedImage src={props.src} alt={props.alt} />,
   h2: ({ children, ...props }: any) => {
-    const id = typeof children === 'string'
-      ? children.toLowerCase().replace(/[^\w\s-]/g, '').replace(/\s+/g, '-')
-      : props.id;
+    const id = props.id || generateHeadingId(getTextContent(children));
     return (
       <SplitHeading {...props} id={id} className="mt-16 mb-6 pb-3 border-b-2 border-primary/20">
         {children}
@@ -80,9 +93,7 @@ export const mdxComponents = {
     );
   },
   h3: ({ children, ...props }: any) => {
-    const id = typeof children === 'string'
-      ? children.toLowerCase().replace(/[^\w\s-]/g, '').replace(/\s+/g, '-')
-      : props.id;
+    const id = props.id || generateHeadingId(getTextContent(children));
     return (
       <h3 {...props} id={id} className="text-2xl font-bold text-text-primary mt-12 mb-4">
         {children}
@@ -108,17 +119,22 @@ export const mdxComponents = {
     <li {...props} className="text-lg text-text-secondary flex items-start gap-3">
       <span className="text-primary mt-1.5 flex-shrink-0">
         <svg className="w-5 h-5" fill="currentColor" viewBox="0 0 20 20">
-          <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zm3.707-9.293a1 1 0 00-1.414-1.414L9 10.586 7.707 9.293a1 1 0 00-1.414 1.414l2 2a1 1 0 001.414 0l4-4z" clipRule="evenodd" />
+          <path
+            fillRule="evenodd"
+            d="M10 18a8 8 0 100-16 8 8 0 000 16zm3.707-9.293a1 1 0 00-1.414-1.414L9 10.586 7.707 9.293a1 1 0 00-1.414 1.414l2 2a1 1 0 001.414 0l4-4z"
+            clipRule="evenodd"
+          />
         </svg>
       </span>
       <span className="flex-1">{children}</span>
     </li>
   ),
   blockquote: ({ children, ...props }: any) => (
-    <blockquote {...props} className="my-8 pl-6 border-l-4 border-primary bg-neutral-light/30 py-4 pr-6 rounded-r-lg">
-      <div className="text-lg text-text-primary italic">
-        {children}
-      </div>
+    <blockquote
+      {...props}
+      className="my-8 pl-6 border-l-4 border-primary bg-neutral-light/30 py-4 pr-6 rounded-r-lg"
+    >
+      <div className="text-lg text-text-primary italic">{children}</div>
     </blockquote>
   ),
   strong: ({ children, ...props }: any) => (
@@ -144,7 +160,10 @@ export const mdxComponents = {
     </div>
   ),
   thead: ({ children, ...props }: any) => (
-    <thead {...props} className="bg-neutral-50 text-text-primary font-semibold border-b border-neutral-200">
+    <thead
+      {...props}
+      className="bg-neutral-50 text-text-primary font-semibold border-b border-neutral-200"
+    >
       {children}
     </thead>
   ),

lib/blog.ts

@@ -109,7 +109,12 @@ export async function getAllPostsMetadata(locale: string): Promise<Partial<PostM
 export async function getAdjacentPosts(
   slug: string,
   locale: string,
-): Promise<{ prev: PostMdx | null; next: PostMdx | null; isPrevRandom?: boolean; isNextRandom?: boolean }> {
+): Promise<{
+  prev: PostMdx | null;
+  next: PostMdx | null;
+  isPrevRandom?: boolean;
+  isNextRandom?: boolean;
+}> {
   const posts = await getAllPosts(locale);
   const currentIndex = posts.findIndex((post) => post.slug === slug);
 
@@ -127,7 +132,7 @@ export async function getAdjacentPosts(
   let isPrevRandom = false;
 
   const getRandomPost = (excludeSlugs: string[]) => {
-    const available = posts.filter(p => !excludeSlugs.includes(p.slug));
+    const available = posts.filter((p) => !excludeSlugs.includes(p.slug));
     if (available.length === 0) return null;
     return available[Math.floor(Math.random() * available.length)];
   };
@@ -154,17 +159,42 @@ export function getReadingTime(content: string): number {
   return Math.ceil(minutes);
 }
 
+export function generateHeadingId(text: string): string {
+  let id = text.toLowerCase();
+  id = id.replace(/ä/g, 'ae');
+  id = id.replace(/ö/g, 'oe');
+  id = id.replace(/ü/g, 'ue');
+  id = id.replace(/ß/g, 'ss');
+
+  id = id.replace(/[*_`]/g, '');
+  id = id.replace(/[^\w\s-]/g, '');
+  id = id
+    .replace(/\s+/g, '-')
+    .replace(/-+/g, '-')
+    .replace(/^-+|-+$/g, '');
+
+  return id || 'heading';
+}
+
+export function getTextContent(node: any): string {
+  if (typeof node === 'string') return node;
+  if (typeof node === 'number') return node.toString();
+  if (Array.isArray(node)) return node.map(getTextContent).join('');
+  if (node && typeof node === 'object' && node.props && node.props.children) {
+    return getTextContent(node.props.children);
+  }
+  return '';
+}
+
 export function getHeadings(content: string): { id: string; text: string; level: number }[] {
   const headingLines = content.split('\n').filter((line) => line.match(/^#{2,3}\s/));
 
   return headingLines.map((line) => {
     const level = line.match(/^#+/)?.[0].length || 0;
-    const text = line.replace(/^#+\s/, '').trim();
-    const id = text
-      .toLowerCase()
-      .replace(/[^\w\s-]/g, '')
-      .replace(/\s+/g, '-');
+    const rawText = line.replace(/^#+\s/, '').trim();
+    const cleanText = rawText.replace(/[*_`]/g, '');
+    const id = generateHeadingId(cleanText);
 
-    return { id, text, level };
+    return { id, text: cleanText, level };
   });
 }