added final frontend with full responsive style but without any logic

frontend/src/components/Header.tsx

@@ -2,8 +2,13 @@ import React from "react";
 
 const Header: React.FC = () => {
   return (
-    <header>
-      <h1>Header</h1>
+    <header className="mb-6 md:mb-10">
+      <h1 className="text-3xl md:text-4xl font-extrabold text-blue-800 tracking-tight drop-shadow-sm">
+        Gegenstand ausleihen
+      </h1>
+      <p className="text-blue-500 mt-1 md:mt-2 text-base md:text-lg font-medium">
+        Schnell und unkompliziert Equipment reservieren
+      </p>
     </header>
   );
 };