custom-responsive-fontsizes-in-functions.php

<?php
function editor_font_sizes($unitOnly = false, $lineHeightOnly = false){
	
	if($rootFont = get_theme_mod("rootTypography")){
		$rootFontSize = "16px";
		$rootLineHeight = 1.3;
		
		if(isset($rootFont["size"]["desktop"]))
			$rootFontSize = $rootFont["size"]["desktop"];
		
		if(isset($rootFont["line-height"]["desktop"]))
			$rootLineHeight = $rootFont["line-height"]["desktop"];
		
		$rootFontSize_int = (int)ltrim($rootFontSize, 'A..z: ');
		
		
		if($unitOnly) return ltrim($rootFontSize, '0..9');
		if($lineHeightOnly) return $rootLineHeight;
		
		$editorFontSizes = [
			[
				'name' => __( 'Tiny', 'lmdm' ),
				'size' => $rootFontSize_int-4,
				'slug' => 'extra-small',
			],
			[
				'name' => __( 'Small', 'lmdm' ),
				'size' => $rootFontSize_int-2,
				'slug' => 'small',
			],
			[
				'name' => __( 'Medium', 'lmdm' ),
				'size' => $rootFontSize_int+4,
				'slug' => 'medium',
			],
			[
				'name' => __( 'LG', 'lmdm' ),
				'size' => $rootFontSize_int+10,
				'slug' => 'large',
			],
			[
				'name' => __( 'XL', 'lmdm' ),
				'size' => $rootFontSize_int+15,
				'slug' => 'larger',
			],
			[
				'name' => __( 'XXL', 'lmdm' ),
				'size' => $rootFontSize_int+20,
				'slug' => 'huge',
			],
			[
				'name' => __( 'Display-1', 'lmdm' ),
				'size' => $rootFontSize_int+35,
				'slug' => 'display-1',
			],
			[
				'name' => __( 'Display-2', 'lmdm' ),
				'size' => $rootFontSize_int+50,
				'slug' => 'display-2',
			],
			[
				'name' => __( 'Display-3', 'lmdm' ),
				'size' => $rootFontSize_int+65,
				'slug' => 'display-3',
			]
		];
		
		return $editorFontSizes;
	}
	return false;
}


add_action( 'wp_enqueue_scripts', 'custom_styles',100);
function custom_styles(){
	// blocksy main style:
	wp_enqueue_style( 'parent-style', get_template_directory_uri() . '/style.css' );
	
	// this could be your style with overwrites:
	if(file_exists( lmdm_path() . '/my-style.css' )){
		$modificated = date( 'Y_m_d_Hi', filemtime( lmdm_path() . '/my-style.css' ) );
		wp_enqueue_style( 'current-style', plugin_dir_url( __FILE__ ) . 'my-style.css','',$modificated );
	}
	// use next line to remove inline css variables introduced with wp 5.9
	//wp_dequeue_style( 'global-styles' );
	
	if($hasEditorFontSizes = editor_font_sizes()){
        $unit = editor_font_sizes(1);
		$css_rules = array();
		$breakpoints = [690,1000];
		
		$rootLineHeight = editor_font_sizes(0,1);
		
		foreach($hasEditorFontSizes as $entry){
			$size_lg = $entry["size"];
			$slug = $entry["slug"];
			
			// make sm sizes smaller!
			$size_sm = $size_lg-floor($size_lg/3)+2; // round to nearest 10
			if($size_sm<10) $size_sm = 10;
			
			$classname = sprintf(".has-%s-font-size",$slug);
			
			$css_attr_sm["font-size"] = sprintf("font-size:%s%s !important",$size_sm,$unit);
			
			// add more custom inline style like this:
			// if($rootLineHeight>1.2)
			//	$css_attr_sm["line-height"] = sprintf("line-height:%s",$rootLineHeight-0.2);
			
			
			// mobile:
			$css_rules[$slug] = "\n".sprintf("%s { %s }",$classname,implode("; ",$css_attr_sm));
			$css_attr_lg["font-size"] = sprintf("font-size:%s%s !important",$size_lg,$unit);
			
			
			if($size_lg < 40){
				$css_rules[$slug] .= "\n  ".sprintf("@media(min-width: %spx){ %s { %s; } }",$breakpoints[0],$classname,implode("; ",$css_attr_lg));
			}else{
				// desktop rules for display sizes / sub-sizes for tablets:
				foreach($breakpoints as $key=>$breakpoint){
					$factor = 1;
					if($breakpoint == 690) $factor = 0.8;
                    $css_attr_lg["font-size"] = sprintf("font-size:%s%s !important",floor($size_lg*$factor),$unit);
					$css_rules[$slug] .= "\n  ".sprintf("@media(min-width: %spx){ %s { %s; } }",$breakpoint,$classname,implode("; ",$css_attr_lg));
				}
            }
            
			
		}
		
		wp_add_inline_style("current-style",implode("\n",$css_rules));
	}
}

function theme_support() {
		
		add_theme_support( 'disable-custom-font-sizes' );
		if($hasEditorFontSizes = editor_font_sizes()){
			add_theme_support(
				'editor-font-sizes',
				$hasEditorFontSizes
			);
		}
		
		remove_theme_support('core-block-patterns');
}
add_action( 'after_setup_theme', 'theme_support',20 );