Optimize theme

. Disable Gutenberg assets: Usually you can use gutenberg blocks on blog and post pages. So disable them in rest pages to improvement page loading.

Open functions.php in your-site/wp-content/themes/cassini-child
Then add this following code:

function cassini_child_disable_gutenberg_wp_enqueue_scripts() {
  if( ! is_singular('post') ) {
     wp_dequeue_style('wp-block-library');
     wp_dequeue_style('wp-block-library-theme');
     wp_dequeue_style('wc-blocks-style');
  }
}
add_action('wp_enqueue_scripts', 'cassini_child_disable_gutenberg_wp_enqueue_scripts', 100);

3. Disable WordPress global style: https://github.com/WordPress/gutenberg/issues/36834

Open functions.php in your-site/wp-content/themes/cassini-child
Then add this following code:

function cassini_child_remove_wp_global_styles() {
     remove_action( 'wp_enqueue_scripts', 'wp_enqueue_global_styles' );
     remove_action( 'wp_body_open', 'wp_global_styles_render_svg_filters' );
}
add_action( 'init', 'cassini_child_remove_wp_global_styles' );