Architecture

Overview
- Framework: Next.js App Router (React 19)
- Styling: Bootstrap 5 with React-Bootstrap components and project SASS overrides
- Theming: Light/Dark theme set via data-bs-theme on <html>, initialized from a cookie or system preference in `src/app/layout.tsx`

Key paths
- App entry/layout: `src/app/layout.tsx`
- Global styles: `src/scss/nbn.scss` (imports Bootstrap, a Bootswatch-like layer, and project styles)
- Navbar: `src/components/Navbar.tsx`
- Register Explorer: `src/app/registers/*`
- Register parsing utilities: `src/utils/register_parser.ts` and `src/utils/register_parsers/*`
- Data: `data/nextreg.txt`

Styling & SASS
- `src/scss/nbn.scss` imports Bootstrap and local overrides in this order:
  1. `variables` (custom Bootstrap variables)
  2. Bootstrap core
  3. `bootswatch` (theme tweaks)
  4. `explorer` (project-specific styles)

Theming bootstrap
- On the server, `layout.tsx` reads the `NBN-theme` cookie (light/dark) and sets `data-bs-theme` on the HTML element.
- On the client, an inline script in the head ensures no flash of incorrect theme by immediately setting the attribute based on cookie or user preference.

Development scripts
- Dev: `pnpm dev` (port 4000 with Turbopack)
- Build: `pnpm build`
- Start: `pnpm start` (defaults to port 3000)
