feat: add Header component

src/components/Header.astro

@@ -0,0 +1,28 @@
+---
+---
+
+<header class="fixed top-0 left-0 w-full h-[78px] bg-[rgba(248,243,238,0.84)] border-b border-border-light backdrop-blur-sm z-50 flex items-center justify-center">
+  <div class="w-[1280px] flex items-center">
+    <div class="flex-1">
+      <a href="/" class="flex items-center gap-2 w-fit">
+        <img src="/assets/logo-icon.png" alt="Talk Pro icon" class="h-[42px] w-[53px] object-cover" />
+        <img src="/assets/logo-wordmark.png" alt="Talk Pro" class="h-6" />
+      </a>
+    </div>
+
+    <nav class="flex items-center gap-7 font-bold text-[14px] text-text-secondary tracking-[-0.09px]">
+      <a href="#" class="hover:text-text-primary transition-colors">Home</a>
+      <a href="#" class="hover:text-text-primary transition-colors">Features</a>
+      <a href="#" class="hover:text-text-primary transition-colors">Product</a>
+      <a href="#" class="hover:text-text-primary transition-colors">Privacy</a>
+      <a href="#" class="hover:text-text-primary transition-colors">About</a>
+    </nav>
+
+    <div class="flex-1 flex justify-end">
+      <button class="bg-brand text-white font-bold text-[14px] px-[22px] py-[13px] rounded-[17px] hover:opacity-90 transition-opacity">
+        Download
+      </button>
+    </div>
+  </div>
+</header>
+<div class="h-[78px]"></div>