Styling the "License the image" link

On this page, the "License this image" link has been created with the following code:

/**********************************************************************************
	Insert license link after the image on single posts - provided by theme support
***********************************************************************************/

add_filter( 'the_content', 'db_insert_before_first_paragraph' );
function db_insert_before_first_paragraph( $content ) { 
    if ( is_single() ) {

        $my_div = '<a href="/purchase/" target="_blank" class="license-caption-link">❤ License this image</a>';
        $first_para_pos = strpos( $content, '<p' );
        $new_content = substr_replace( $content, $my_div, $first_para_pos, 0 );
        
        return $new_content;
    }
    
    return $content;

}

While trying to style the link with CSS, it seems like something is wrong. The style is also affecting the image (background color, padding), which it should not.

Also, I have the same link on this page created with the following code:

/********************************************************************************************************
	Create automatic excerpt for the stories page and insert the license link - provided by theme support
*********************************************************************************************************/

function catch_that_image() {
  global $post, $posts;
  $first_img = '';
  ob_start();
  ob_end_clean();
  $output = preg_match_all('/<img.+?src=[\'"]([^\'"]+)[\'"].*?>/i', $post->post_content, $matches);
  $first_img = $matches[1][0];

  if(empty($first_img)) {
    $first_img = "/path/to/default.png";
  }
  return '<img src="'.$first_img.'" /><a href="/purchase/" target="_blank" class="license-caption-link">❤ License this image</a>';
}
add_shortcode('first-image', 'catch_that_image');

The style for both of the links should be the same (top and bottom margin). Please help to fix this!