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 Spinner component:

import AgSpinner from 'agnostic-astro/Spinner.astro';

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

...
<AgSpinner showOnMount size="small" />
<AgSpinner showOnMount />
<AgSpinner showOnMount size="large" />
<AgSpinner showOnMount size="xlarge" />
<div class="mbs24 text-center">In 5 seconds a customized spinner will be shown below…</span>
<AgSpinner class="manuallyShow mbs40" showOnMount={false} size="xlarge" style="--agnostic-spinner-color: salmon;" />
...and so on
<script>
  setTimeout(() => {
    // aria-busy toggles spinner's visibility. By default showOnMount is true but
    // in this case, we've set: showOnMount={false} allowing control via JavaScript
    document.querySelector('.manuallyShow').setAttribute('aria-busy', 'true');
  }, 5000);
</script>