The agnostic-astro package utilizes XElement under-the-hood in order to provide build-time Astro components. These build-time components will help your project get closer to realizing a mostly no client-side runtime…if you do it right, this should mean an all-green 100% Lighthouse performance score! Leverage the benefits of Islands architecture by sending mostly server built agnostic-astro components. Then, sprinkle client-hydrated ones only as needed.

Ensure you've installed the agnostic-astro npm package (note this installs depedency agnostic-css as well):

npm i agnostic-astro

and then import common.min.css from your “base layout” (you should only need to do this in once place as this is global CSS). This brings in the required CSS custom properties, reset, and properties:

import 'agnostic-css/public/css-dist/common.min.css';

Then you can import Astro Loader component:

import AgLoader from 'agnostic-astro/Loader.astro';

Here's the agnostic-astro Loader component in use:

...
<AgLoader class="mbs40" size="small" />
<AgLoader class="mbs40" label="My screenreader only label for accessibility" />
<AgLoader class="mbs40" size="large" />
<div class="h4 mbs24">In 5 seconds a customized Loader will be shown below…</div>
<AgLoader class="manuallyShow mbs40" showOnMount={false} size="xlarge" style="--agnostic-loading-color: salmon;" />
<div class="h4 mbs24 mbe24">Center via flex container</div>
<div class="flex justify-center">
  <AgLoader class="mbs40" size="large" />
</div>
...and so on
<script>
  setTimeout(() => {
    document.querySelector('.manuallyShow').setAttribute('aria-busy', 'true');
  }, 5000);
</script>