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+# URL-Driven Section Routing — Design
+
+**Date:** 2026-05-07  
+**Status:** Approved
+
+## Goal
+
+Replace the single-page client-state accordion with multi-page URL-driven routing. Each portfolio section gets its own static URL. The sections list remains visible at all times; clicking a section heading navigates to its page.
+
+## Route Structure
+
+Delete `app/page.tsx`. Create `app/[[...slug]]/page.tsx` (optional catchall).
+
+| URL | Active section |
+|---|---|
+| `/` | `sections[0].slug` (first section, URL stays `/`) |
+| `/intro` | `intro` |
+| `/bio` | `bio` |
+| `/skills` | `skills` |
+| `/experience` | `experience` |
+| `/projects` | `projects` |
+
+`generateStaticParams` emits one entry per section plus the root:
+```ts
+[{}, { slug: ['intro'] }, { slug: ['bio'] }, ...]
+```
+
+## Component Changes
+
+### `SectionAccordion` (entity)
+
+- Replace `onClick: () => void` prop with `href: string`
+- Inactive state: render `<Link href={href}>` instead of `<button onClick>`
+- No `'use client'` needed (already a server component)
+
+### `SectionsAccordion` (widget)
+
+- Remove `'use client'` directive and `useState`
+- Add `activeSlug: string` prop (passed from page server component)
+- Pass `href={`/${section.slug}`}` to each `SectionAccordion`
+- Keep `children` slot pattern for RSC content
+
+### `SidebarNav` (widget)
+
+- Remove `IntersectionObserver` and `scrollToSection`
+- Add `usePathname()` hook for active detection
+- Active rule: `pathname === `/${item.id}`` or `(pathname === '/' && item is first)`
+- Items become `<Link href={`/${item.id}`}>` instead of `<button onClick>`
+- Keep `'use client'` (required for `usePathname`)
+
+### `MobileNav` (widget)
+
+- Section items become `<Link>` that also close the menu on navigate
+- Use `usePathname` in a `useEffect` to close menu on route change (replaces manual close-on-click)
+
+## Data Flow
+
+```
+[[...slug]]/page.tsx  (RSC)
+  ├─ fetch sections[]
+  ├─ activeSlug = params?.slug?.[0] ?? sections[0].slug
+  ├─ notFound() if activeSlug not in sections
+  ├─ SidebarNav items={navItems}           ← usePathname for active state
+  └─ SectionsAccordion sections activeSlug
+       ├─ SectionAccordion href="/"    isActive=true  → SectionFactory content
+       ├─ SectionAccordion href="/bio"               → Link
+       └─ SectionAccordion href="/skills"            → Link
+```
+
+No client state in the section list. `SidebarNav` remains client-only for `usePathname`.
+
+## Error Handling
+
+- Unknown slug → `notFound()` at page level (404 static page)
+- Empty sections list → `notFound()` at page level
+
+## Testing
+
+- `SectionsAccordion`: drop interaction (click/activate) tests; replace with prop-driven assertions — correct `isActive` and `href` per section given `activeSlug`
+- `SidebarNav`: drop `IntersectionObserver` mock; mock `usePathname`; assert active link class
+- `MobileNav`: items become links; assert close-on-navigate via `usePathname` effect
+- `[[...slug]]/page.tsx`: no unit tests (pure orchestration of tested components)
+
+## No New Dependencies
+
+`next/link` and `next/navigation` already present.