💄 update blogpost ui

Signed-off-by: Sindre Kjelsrud <kjelsrudsindre@gmail.com>

src/components/BlogHeader.astro

@@ -0,0 +1,29 @@
+---
+import ThemeIcon from './ThemeIcon.astro';
+
+function toggleTheme() {
+  const currentTheme = document.body.getAttribute('data-theme');
+  document.body.setAttribute('data-theme', currentTheme === 'dark' ? 'light' : 'dark');
+}
+---
+
+<header class="flex justify-between items-center py-5">
+  <div>
+    <a class="text-l font-semibold" href="/blog">
+      <svg class="w-6 h-6 text-gray-800 dark:text-white" style="color: var(--color-current);"  aria-hidden="true" xmlns="http://www.w3.org/2000/svg" width="24" height="24" fill="none" viewBox="0 0 24 24">
+        <path stroke="currentColor" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="m15 19-7-7 7-7"/>
+      </svg>
+    </a>
+  </div>
+  <ThemeIcon />
+</header>
+
+<style>
+[data-theme='dark'] {
+  --color-current: #9AD3BB;
+}
+
+[data-theme='light'] {
+  --color-current: #3B2C29;
+}
+</style>