Astro Development

Project Setup

• •Astro 5 with React integration and Tailwind v4 via Vite plugin.
• •Site: https://sami.github.io, Base: /selco.
• •Config: astro.config.mjs.

Routing

Pages live in src/pages/ and map directly to routes:

src/pages/index.astro           → /selco/
src/pages/calculators/index.astro → /selco/calculators/
src/pages/calculators/tiles.astro → /selco/calculators/tiles/

Base URL

Critical: All internal links must use import.meta.env.BASE_URL. This resolves to /selco in production. Hardcoded paths break on GitHub Pages.

---
const base = import.meta.env.BASE_URL;
---
<a href={`${base}/calculators`}>Calculators</a>

Islands Architecture

Use Astro for all static content. Only use React components where interactivity is needed (forms, calculators, dynamic UI).

---
import TileCalculator from '../../components/calculators/TileCalculator';
---
<!-- Static content rendered by Astro -->
<h1>Tile Calculator</h1>
<p>Calculate how many tiles you need.</p>

<!-- Interactive island hydrated by React -->
<TileCalculator client:load />

Hydration Directives

• •client:load — Hydrate immediately. Use for calculators (above the fold, interactive on load).
• •client:visible — Hydrate when scrolled into view. Use for below-fold interactive content.
• •client:idle — Hydrate when browser is idle. Use for non-urgent interactivity.

Default to client:load for calculator components since users visit the page to use them.

Layout

All pages use BaseLayout.astro which provides:

• •SEO head (via SEOHead component)
• •Sticky header with navigation
• •Main content area via <slot />
• •Disclaimer and feedback footer

---
import BaseLayout from '../../layouts/BaseLayout.astro';
---
<BaseLayout title="Page Title" description="Page description for SEO.">
  <!-- page content -->
</BaseLayout>

Passing Data to React

Pass data from Astro frontmatter to React components as props. Do NOT fetch data inside React components if it can be resolved at build time.

---
const base = import.meta.env.BASE_URL;
---
<Calculator baseUrl={base} client:load />