feat: add float animation and pink drop shadow to header logo

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

layouts/partials/logo.html

@@ -5,4 +5,4 @@
     class — CSS classes on the <img> element (default: "h-9 w-auto")
 */ -}}
 {{- $class := .class | default "h-9 w-auto" -}}
-<img src="/logo.svg" class="{{ $class }}" alt="{{ site.Title }}" width="512" height="512">
+<img src="/logo.svg" class="{{ $class }} logo-img" alt="{{ site.Title }}" width="512" height="512">