You don’t need to add a CSS file to hype, you can set CSS in the ‘head’ area. You can edit the contents of the <head>…</head> of your exported .html file by clicking on ‘Edit HTML Head’ in the Document Inspector.
Just add:
<style>
...
</style>
And you can set your own CSS which will be exported to your Hype document’s .HTML file.
This also shows a cursor in action: Change mouse cursor on rollover or use a custom image for cursor
Here’s a demo document to see a coupe methods. The first scene is the method I think you should use. The second scene is with a remote cursor loaded from a URL.
CustomCursor.hype 2.zip (79.8 KB)