I’m writing this little plugin and my php file at one point includes a small html file, like this:

 function draw_editor(){
  include HANDLER_INCLUDE_URL.'/draw.html';
 }

But the problem is, that the html in turn needs some css and js files. And no matter what I try, the console shows me 404’s.
My folder structure looks like this:
myPlugin/includes/css

The .php is in myPlugin, the html in myPlugin/includes and the css in myPlugin/includes/css

No matter what I try, the html does not find the files it needs. So far I tried:

href="css/style.css" />
href="/css/style.css" />
href="../css/style.css" />
href="style.css" />
href="../wp-content/plugins/myPlugin/includes/css/style.css" />
href="/var/www/wordpress/wp-content/myPlugin/includes/style.css" />

nothing works.
If I smuggle a <?php echo(__DIR__) ?> in the html, I get /var/www/wordpress/wp-content/myPlugin/includes

Can someone please tell me what I’m doing wrong here?