refactor(styles): enhance glass effects, card designs, and transitions across components

- Replaced `client:only="react"` with `client:load transition:persist="header"` for `GlassHeader` to improve page transitions and header consistency.
- Updated card and surface designs with refined colors, borders, and shadows for a cleaner, modern look.
- Adjusted CSS variables for better contrast and distinct layers.
- Applied consistent blur and backdrop styles across components for visual cohesion.

src/pages/hire.astro

@@ -14,7 +14,7 @@ const pageTitle = lang === 'zh' ? '合作' : 'Hire Me';
 ---
 
 <Layout title={pageTitle}>
-  <GlassHeader lang={lang} client:only="react" />
+  <GlassHeader lang={lang} client:load transition:persist="header" />
   <main class="min-h-screen">
     <!-- Hire Page Hero -->
     <section class="py-24 relative overflow-hidden">