docs: forbid text gradients in style guide and replace existing text gradient with solid color in hero

.agents/AGENTS.md

@@ -13,3 +13,5 @@
 - **Don't Auto-Play Videos with Sound:** This is highly disruptive; give users full control over media.
 - **Don't Overcrowd the Interface:** Over-emphasizing every element dilutes the page's purpose. Leave ample whitespace around sections and text.
 - **Don't Open Internal Links in New Tabs:** Let users control their own browsing journey instead of hijacking their back button.
+- **Don't Use Text Gradients:** Avoid using gradient colors on text elements to maintain maximum readability, high contrast, and a clean, non-AI-generated look.
+

src/components/HeroAndLiquidGlass.astro

@@ -19,7 +19,7 @@
         
         <h1 class="text-4xl sm:text-7xl font-extrabold tracking-tight text-slate-900 dark:text-white leading-[1.1] transition-colors duration-300">
           Sorgenfreies Hosting <br/>
-          <span class="bg-clip-text text-transparent bg-gradient-to-r from-sky-600 to-indigo-600 dark:from-sky-400 dark:via-indigo-300 dark:to-white">
+          <span class="text-sky-600 dark:text-sky-400">
             für Ihre Website.
           </span>
         </h1>