jett-theme/functions.php

<?php

/* Remove default CSS variables that come with Wordpress
  https://github.com/WordPress/gutenberg/issues/56180#issuecomment-1819222376
*/
function custom_wp_theme_json_default( $theme_json ) {
	$new_data = array(
		'version'  => 2,
		'settings' => array(
			'color'  => array(
				'palette'   => array(),
				'gradients' => array(),
			),
			'shadow' => array(
				'presets' => array(),
			),
			'typography' => array(
				'fontSizes' => array(),
			),
			// 'dimensions' => array(
			// 	'aspectRatios' => array(),
			// ),
			// 'spacing' => array(
			// 	'spacingScale' => array(
			// 		'steps' => 0,
			// 	),
			// ),
		),
	);
	return $theme_json->update_with( $new_data );
}
add_filter( 'wp_theme_json_data_default', 'custom_wp_theme_json_default' );

// enable svg uploads
add_filter( 'wp_check_filetype_and_ext', function($data, $file, $filename, $mimes) {

  global $wp_version;
  if ( $wp_version !== '4.7.1' ) {
     return $data;
  }

  $filetype = wp_check_filetype( $filename, $mimes );

  return [
      'ext'             => $filetype['ext'],
      'type'            => $filetype['type'],
      'proper_filename' => $data['proper_filename']
  ];

}, 10, 4 );
function cc_mime_types($mimes) {
  $mimes['svg'] = 'image/svg+xml';
  return $mimes;
}
add_filter('upload_mimes', 'cc_mime_types');

// define block styles
function jett_block_styles() {
	register_block_style(
		'core/heading',
		array(
			'name'         => 'gradient',
			'label'        => __( 'Gradient', 'jett' ),
			'inline_style' => '
				.wp-block-heading.is-style-gradient {
					background: var(--wp--preset--gradient--violet-to-green);
					-webkit-background-clip: text;
					-webkit-text-fill-color: transparent;
					line-height: 1.1;
				}
			'
		)
	);
	register_block_style(
		'core/paragraph',
		array(
			'name'         => 'gradient',
			'label'        => __( 'Gradient', 'jett' ),
			'inline_style' => '
				p.is-style-gradient {
					background: var(--wp--preset--gradient--violet-to-green);
					-webkit-background-clip: text;
					-webkit-text-fill-color: transparent;
					line-height: 1.1;
				}
			'
		)
	);
	register_block_style( 
		'core/list', 
		array(
			'name'         => 'arrow',
			'label'        => __( 'Arrow', 'lex-scotland' ),
			'inline_style' => '
				ul.is-style-arrow {
					list-style: none;
				}
				ul.is-style-arrow div {
					display: inline;
				}
				ul.is-style-arrow li::before {
					content: "→";
					margin-right: 0.5em;
					font-weight: bold;
				}
			'
		)
	);
}
add_action( 'init', 'jett_block_styles' );