implemented header and dark theme.

src/components/Separator.jsx

@@ -0,0 +1,9 @@
+function Separator() {
+  return (
+    <div className="h-[2px]">
+        <div className="h-full w-full bg-white rounded-md"></div>
+    </div>
+  )
+}
+
+export default Separator;