Build portfolio site - Astro + Tailwind, trilingual structure

- Astro 5.x + Tailwind CSS 4.x
- Dark theme with warm orange accent (#f97316)
- i18n routing: /en/, /de/, /es/ (English content complete, DE/ES placeholders)
- Components: Navbar, Hero, Services (4 cards), Projects (4 case studies), About, Contact, Footer
- Fade-in scroll animations
- Mobile-responsive with hamburger menu
- All content from content/*.md integrated
- SEO meta tags, Open Graph tags
- Clean build with no errors

astro.config.mjs

@@ -0,0 +1,18 @@
+// @ts-check
+import { defineConfig } from 'astro/config';
+
+import tailwindcss from '@tailwindcss/vite';
+
+// https://astro.build/config
+export default defineConfig({
+  i18n: {
+    defaultLocale: 'en',
+    locales: ['en', 'de', 'es'],
+    routing: {
+      prefixDefaultLocale: true
+    }
+  },
+  vite: {
+    plugins: [tailwindcss()]
+  }
+});