Overhaul portfolio UX with cinematic motion system and stronger technical SEO foundations

[Copilot]

The site needed a complete visual and interaction reset plus stronger SEO implementation. This PR replaces the existing presentation layer with a new cinematic UI system and upgrades metadata/structured signals to improve discoverability.

• UI + Information Architecture

  • Reworked index.html into clearer, scan-friendly sections (hero, work, research, about, contact).
  • Updated content hierarchy, CTA placement, and card/timeline layouts for faster narrative flow.
  • Improved semantic structure and accessibility-oriented markup (sectioning, labels, descriptive image alt text).

• Styling + Motion Language

  • Replaced styles.css with a new design system (color tokens, glass panels, gradients, typography, responsive spacing).
  • Introduced cinematic motion elements (noise/vignette/orbs, reveal transitions, hover depth, magnetic CTA behavior).
  • Added robust responsive behavior and reduced-motion handling to keep effects performant and optional.

• Client-Side Interaction Layer

  • Rebuilt script.js to drive new interactions: theme toggle persistence, scroll progress bar, section-aware nav highlighting, reveal observers, animated counters, and tilt/magnetic micro-interactions.
  • Kept behavior framework-free and aligned with the repo’s static architecture.

• SEO + Social Preview Improvements

  • Expanded head metadata: title, description, keywords, canonical, robots directives.
  • Added richer Open Graph and Twitter card tags for share previews.
  • Upgraded structured data to a graph (Person, WebSite, ItemList) for clearer entity/project signaling.
  • Refreshed sitemap.xml recency and crawl hints (lastmod, changefreq, priority).

<meta name="robots" content="index, follow, max-image-preview:large, max-snippet:-1, max-video-preview:-1">

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@graph": [
    { "@type": "Person", "name": "Upendra Khanal", "url": "https://upendrakhanal.com.np" },
    { "@type": "WebSite", "name": "Upendra Khanal Portfolio", "url": "https://upendrakhanal.com.np" },
    { "@type": "ItemList", "name": "Featured Projects" }
  ]
}
</script>