namespace StackExchangeWordPress;

add_action( 'wp_loaded', __NAMESPACE__ . 'wp_loaded' );
function wp_loaded() {
  $role = 'author';
  if( ! is_current_user_in_role( $role ) ) {
    return;
  }
  add_action( 'wp_enqueue_scripts', __NAMESPACE__ . 'wp_enqueue_scripts' );
  add_action( 'wp_footer', __NAMESPACE__ . 'wp_footer' );
}

function wp_footer() { ?>
  <div class="hidden or-some-other-class-that-wont-be-shown">
    <!-- Some other HTML code -->
  </div>
<?php }

function wp_enqueue_scripts() {
  //* Enqueue the CSS that will initially hide the hidden div
  //* Or it could be in another stylesheet already enqueued
  wp_enqueue_style( 'name-of-style', PATH_TO . 'style-name.css' );

  //* In the javascript file, pop up the hidden div
  wp_enqueue_script( 'name-of-script', PATH_TO . 'script-name.js' );
}

function is_current_user_in_role( $role ) {
  return in_array( $role, (array) wp_get_current_user()->roles )
}