customize the HTML/styling of links in PMPro-generated emails

my_pmpro_change_email_link_styling.php

// customize the HTML/styling of links in PMPro-generated emails
function my_pmpro_change_email_link_styling( $data, $email ){

  /*--- An array of variable names. Change or add to this to style different links.
      default options: 'invoice_link', 'levels_link', 'login_link' ---*/
  $links_to_change = array( 'invoice_link', 'login_link' );

  $newdata = [];
  foreach( $data as $variable => $value ) {
    if( in_array( $variable, $links_to_change) && strpos( $value, "http" ) !== false ) {

      /*--- Make the link color red. change this line to change the styling of the link ---*/
      $newdata[$variable] = '<a href="' . $data[$variable] . '" style="color:rgb(255,0,0)" !important>'.$data[$variable].'</a>';

    } else {
      $newdata[$variable] = $data[$variable];
    }
  }
  return $newdata;
}
add_filter( 'pmpro_email_data', 'my_pmpro_change_email_link_styling', 30, 2 );