Can I have access to my mobile hardware from the browser? Yes! Besides being able to play with services like camera and GPS most modern browsers today have the ability to access cool features like fingerprint and even Web-XR.
If you haven't come across Typed Object Model (or Typed OM) yet you would be forgiven as it's pretty new. It falls under the CSS Houdini suite of API's and on the surface seems the least exciting. However, it underpins all of them and will eventually change how we view CSS as a language.