fixed mismatched borders on post header, added flex wrap to nav bar

frontend/components/Header.tsx

@@ -35,7 +35,7 @@ export default function Header() {
   return (
     <header>
       <nav>
-        <div class="bg-[#313244] flex justify-center space-x-6 p-4">
+        <div class="bg-[#313244] flex flex-wrap justify-center space-x-6 p-4">
           {headerLinks.map((l) => {
             const newTab = l.newTab ? "_blank" : "_self";
             return (