Add ver filemtime to styles

style_version_always_actual.php

<?php 
add_filter( 'script_loader_src', 'remove_src_version' );
add_filter( 'style_loader_src', 'remove_src_version' );
function remove_src_version ( $src ) {
  global $wp_version;
  $version_str = '?ver='.$wp_version;
  $version_str_offset = strlen( $src ) - strlen( $version_str );
  
  $version_str_alt = '&ver='.$wp_version;
  $version_str_offset_alt = strlen( $src ) - strlen( $version_str_alt );
  
  if( substr( $src, $version_str_offset ) == $version_str )
    $without_ver = substr( $src, 0, $version_str_offset );
  elseif (substr( $src, $version_str_offset_alt ) == $version_str_alt)  {
    $without_ver = substr( $src, 0, $version_str_offset_alt );
  }
  else  $without_ver = $src; //return original url if no version

  $file_path = str_replace(get_stylesheet_directory_uri(), get_stylesheet_directory(), $without_ver);
  
  $file_path_alt = str_replace(get_template_directory_uri(), get_template_directory(), $without_ver);
  
  
  if (file_exists($file_path)) {
    return $without_ver.'?ver='.filemtime($file_path);
  } elseif (file_exists($file_path_alt)) {
    return $without_ver.'?ver='.filemtime($file_path_alt);
  }
  else return $without_ver;

}