Tailwind v4 migration, massive SEO optimization, and fixes

- Migrate to Tailwind CSS v4 with @theme, @layer, @plugin syntax
- Upgrade to Next.js 16.1, React 19.2, TypeScript 5.9.3
- Add 8 technology landing pages (Next.js, React, TypeScript, Tailwind CSS, Claude AI, Python, n8n, KI-Agenten)
- Expand SEO keywords across all locales (de/en/sr) for home, layout, cities, services
- Add tech-specific keywords to all 22 city pages
- Add FAQ schema + seoKeywords to service detail pages
- Add CollectionPage JSON-LD to blog listing
- Fix city page: dynamic region, BASE_URL canonicals, x-default hreflang
- Rewrite terms page with full German AGB, English and Serbian translations
- Remove dead crypto import and unused CSRF middleware (Edge Runtime fix)
- Remove crawlDelay from robots.ts
- Update sitemap with technology pages (~198 indexed URLs)
- Remove deprecated tailwind.config.js

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/sections/Experience.tsx

@@ -73,7 +73,7 @@ const Experience = () => {
           viewport={{ once: true }}
           transition={{ duration: 0.8, ease: [0.25, 0.46, 0.45, 0.94] }}
         >
-          <h2 className="text-3xl font-bold text-white text-center mb-12">
+          <h2 className="text-2xl sm:text-3xl md:text-4xl font-bold text-white text-center mb-8 sm:mb-12">
             {t('title')}
           </h2>
           <div
@@ -135,7 +135,7 @@ const Experience = () => {
             <div className="flex justify-center items-center gap-4 mt-8">
               <button
                 onClick={() => currentPage > 0 && setCurrentPage(prev => prev - 1)}
-                className="text-zinc-400 hover:text-white transition-all duration-300 p-2 text-2xl font-light disabled:opacity-30"
+                className="text-zinc-400 hover:text-white transition-all duration-300 p-3 sm:p-2 text-2xl font-light disabled:opacity-30"
                 disabled={currentPage === 0}
                 aria-label="Previous page"
               >
@@ -147,21 +147,20 @@ const Experience = () => {
                     key={index}
                     onClick={() => setCurrentPage(index)}
                     className="relative flex items-center justify-center transition-all duration-300"
-                    style={{ width: '24px', height: '24px' }}
+                    className="relative flex items-center justify-center w-10 h-10 sm:w-6 sm:h-6 transition-all duration-300"
                     aria-label={`Page ${index + 1}`}
                   >
                     <span
                       className={`rounded-full transition-all duration-300 ${
-                        index === currentPage ? 'bg-white' : 'bg-zinc-600 hover:bg-zinc-400'
+                        index === currentPage ? 'bg-white w-2.5 h-2.5' : 'bg-zinc-600 hover:bg-zinc-400 w-2 h-2'
                       }`}
-                      style={{ width: '8px', height: '8px' }}
                     />
                   </button>
                 ))}
               </div>
               <button
                 onClick={() => currentPage < totalPages - 1 && setCurrentPage(prev => prev + 1)}
-                className="text-zinc-400 hover:text-white transition-all duration-300 p-2 text-2xl font-light disabled:opacity-30"
+                className="text-zinc-400 hover:text-white transition-all duration-300 p-3 sm:p-2 text-2xl font-light disabled:opacity-30"
                 disabled={currentPage === totalPages - 1}
                 aria-label="Next page"
               >